We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat

On Tuesday, March 30, 2021 at 1:08:53 PM UTC-5, Pat wrote:
We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat

A very quick look on Ebay showed different sized compressors. Some are
1/10 hp, others are 1/3 hp. Are the compressors the same within a single unit?

On Tue, 30 Mar 2021 11:43:37 -0700 (PDT), Dean Hoffman
wrote:

On Tuesday, March 30, 2021 at 1:08:53 PM UTC-5, Pat wrote:
We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat

A very quick look on Ebay showed different sized compressors. Some are
1/10 hp, others are 1/3 hp. Are the compressors the same within a single unit?

I hadn't thought of that possibility. I'll do some research. It's a
model 642 by the way.

Thanks for the quick reply,
Pat

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

On Tue, 30 Mar 2021 17:18:47 -0400, wrote:

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

After reading Dean Hoffman's suggestion, I did a little more research.
I didn't find much other than lots of warnings not to use generators.
Sub-zero didn't really say why, though. They did say that starting
both compressors could peak at 24 amps. But, since they recommend a
15 amp breaker, that peak can't last very long. Who knows what the
voltage would drop to at the compressors during that peak. Other than
duplicating your variac setup, the only thing I can think to try next
time is moving the battery/inverter to the kitchen to avoid some of
the voltage drop. The inverter claims 1500 watts continuous with 3000
watts peak. Sub-zero's stated 24 amps peak would very near that 3000
watts max, so what I measured at 114vac during a 800 watt load might
actually be much lower during that peak demand. We've lived here for
almost 20 years and that was the first power outage that lasted longer
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".

Thanks for your comments,
Pat

In article ,
says...
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".




I have had very few power outages, but did buy a dual fuel generator.
By only using propane it can sit there for years and be ready to go for
half an hour or days if needed, then shut off and not have to mess with
it to the next time. Propane will not go bad and nothing left in the
engine like it would if gas. Caught one on sale that is about 3.5 to 4
KW for only $ 350 including shipping.

It is batery or pull start, so I do check the charge of the battery
every few months.

On Wednesday, March 31, 2021 at 6:37:51 AM UTC-4, Pat wrote:
On Tue, 30 Mar 2021 17:18:47 -0400, wrote:

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg
After reading Dean Hoffman's suggestion, I did a little more research.
I didn't find much other than lots of warnings not to use generators.
Sub-zero didn't really say why, though. They did say that starting
both compressors could peak at 24 amps. But, since they recommend a
15 amp breaker, that peak can't last very long. Who knows what the
voltage would drop to at the compressors during that peak. Other than
duplicating your variac setup, the only thing I can think to try next
time is moving the battery/inverter to the kitchen to avoid some of
the voltage drop. The inverter claims 1500 watts continuous with 3000
watts peak. Sub-zero's stated 24 amps peak would very near that 3000
watts max, so what I measured at 114vac during a 800 watt load might
actually be much lower during that peak demand. We've lived here for
almost 20 years and that was the first power outage that lasted longer
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".

Thanks for your comments,
Pat

I would suspect that the freezer compressor takes more current to start.
So the fridge one wins out, it starts and then it reduces the available
current. IDK if they have electronic smarts that figure that out or if
it's just a thermal breaker for the compressor. If it's the latter you'd think
you'd hear a click when the freezer one stops trying.

Another consideration is that you're fiddling with Sub Zero that cost
thousands and repair would not be cheap either. I'd make sure I had
an inverter plenty big. Inverters are cheap compared to a repair bill
if the compressor gets hosed.

On Tue, 30 Mar 2021 17:18:47 -0400, posted for all of us to
digest...


On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

O O O is that a listed raceway? ;-)

--
Tekkie

On Wed, 31 Mar 2021 06:37:44 -0400, Pat
wrote:

On Tue, 30 Mar 2021 17:18:47 -0400, wrote:

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

After reading Dean Hoffman's suggestion, I did a little more research.
I didn't find much other than lots of warnings not to use generators.
Sub-zero didn't really say why, though. They did say that starting
both compressors could peak at 24 amps. But, since they recommend a
15 amp breaker, that peak can't last very long. Who knows what the
voltage would drop to at the compressors during that peak. Other than
duplicating your variac setup, the only thing I can think to try next
time is moving the battery/inverter to the kitchen to avoid some of
the voltage drop. The inverter claims 1500 watts continuous with 3000
watts peak. Sub-zero's stated 24 amps peak would very near that 3000
watts max, so what I measured at 114vac during a 800 watt load might
actually be much lower during that peak demand. We've lived here for
almost 20 years and that was the first power outage that lasted longer
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".

Thanks for your comments,
Pat

If you have access to a scope it might not be a bad idea to look at
the wave form under load. It might be pretty ugly.
My generator wasn't really that bad.

http://gfretwell.com/Propaneproject/Waveform.jpg

On Wed, 31 Mar 2021 16:53:26 -0400, Tekkie©
wrote:


On Tue, 30 Mar 2021 17:18:47 -0400, posted for all of us to
digest...


On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

O O O is that a listed raceway? ;-)

That is just a "duct", the wiring method is a cable and the boxes are
listed.
The assembly is not listed but it is made up from "recognized" parts.
As AHJ here it is "approved" on a 90.4.
"Come and get me copper"!
;-)

On Wed, 31 Mar 2021 21:51:47 -0400, posted for all of us to
digest...


On Wed, 31 Mar 2021 06:37:44 -0400, Pat
wrote:

On Tue, 30 Mar 2021 17:18:47 -0400, wrote:

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

After reading Dean Hoffman's suggestion, I did a little more research.
I didn't find much other than lots of warnings not to use generators.
Sub-zero didn't really say why, though. They did say that starting
both compressors could peak at 24 amps. But, since they recommend a
15 amp breaker, that peak can't last very long. Who knows what the
voltage would drop to at the compressors during that peak. Other than
duplicating your variac setup, the only thing I can think to try next
time is moving the battery/inverter to the kitchen to avoid some of
the voltage drop. The inverter claims 1500 watts continuous with 3000
watts peak. Sub-zero's stated 24 amps peak would very near that 3000
watts max, so what I measured at 114vac during a 800 watt load might
actually be much lower during that peak demand. We've lived here for
almost 20 years and that was the first power outage that lasted longer
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".

Thanks for your comments,
Pat

If you have access to a scope it might not be a bad idea to look at
the wave form under load. It might be pretty ugly.
My generator wasn't really that bad.

http://gfretwell.com/Propaneproject/Waveform.jpg

I always wanted a scope but never got one. I was always interested in observing
the A/C waveform but I was afraid if I plugged in the inputs I would blow the
sucker up. A ham gave me one that weighed about 100lbs but had no leads. It sat
in my living room until my wife said to get rid of it. I built a Heathkit
automotive one which worked fine. Any recommendations?

--
Tekkie

On Wed, 31 Mar 2021 21:57:53 -0400, posted for all of us to
digest...


On Wed, 31 Mar 2021 16:53:26 -0400, Tekkie©
wrote:


On Tue, 30 Mar 2021 17:18:47 -0400, posted for all of us to
digest...


On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

O O O is that a listed raceway? ;-)

That is just a "duct", the wiring method is a cable and the boxes are
listed.
The assembly is not listed but it is made up from "recognized" parts.
As AHJ here it is "approved" on a 90.4.
"Come and get me copper"!
;-)

First you deny me shelter and now you deny me a fine. I think I should
confiscate the scope and variac for my emotional health! Send it overnite.

--
Tekkie

On 04/01/2021 12:37 PM, Tekkie� wrote:
I always wanted a scope but never got one. I was always interested in observing
the A/C waveform but I was afraid if I plugged in the inputs I would blow the
sucker up. A ham gave me one that weighed about 100lbs but had no leads. It sat
in my living room until my wife said to get rid of it. I built a Heathkit
automotive one which worked fine. Any recommendations?

https://www.electronics-lab.com/top-...inkers-makers/


For a real low cost solution you can use the computer's audio card and
free softwa

https://listoffreeware.com/best-free...tware-windows/


20 years ago or so Radio Shack had an o-scope probe to use with a
computer. The frequency range was limited by the processing power of the
day but it was handy for some things.

On Thu, 1 Apr 2021 14:37:33 -0400, Tekkie© wrote:


On Wed, 31 Mar 2021 21:51:47 -0400, posted for all of us to
digest...


On Wed, 31 Mar 2021 06:37:44 -0400, Pat
wrote:

On Tue, 30 Mar 2021 17:18:47 -0400, wrote:

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

After reading Dean Hoffman's suggestion, I did a little more research.
I didn't find much other than lots of warnings not to use generators.
Sub-zero didn't really say why, though. They did say that starting
both compressors could peak at 24 amps. But, since they recommend a
15 amp breaker, that peak can't last very long. Who knows what the
voltage would drop to at the compressors during that peak. Other than
duplicating your variac setup, the only thing I can think to try next
time is moving the battery/inverter to the kitchen to avoid some of
the voltage drop. The inverter claims 1500 watts continuous with 3000
watts peak. Sub-zero's stated 24 amps peak would very near that 3000
watts max, so what I measured at 114vac during a 800 watt load might
actually be much lower during that peak demand. We've lived here for
almost 20 years and that was the first power outage that lasted longer
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".

Thanks for your comments,
Pat

If you have access to a scope it might not be a bad idea to look at
the wave form under load. It might be pretty ugly.
My generator wasn't really that bad.

http://gfretwell.com/Propaneproject/Waveform.jpg

I always wanted a scope but never got one. I was always interested in observing
the A/C waveform but I was afraid if I plugged in the inputs I would blow the
sucker up. A ham gave me one that weighed about 100lbs but had no leads. It sat
in my living room until my wife said to get rid of it. I built a Heathkit
automotive one which worked fine. Any recommendations?

I would look for an old tektronics like that 453. They were built to
spec for IBM and real tanks. I don't think I ever saw a bad one and we
beat the hell out of them. I gave away 3 after they closed our office.
IBM must have dumped 10,000-15,000. Every 360/370 account had one and
a lot of CEs also had one in their car. I fear a lot of them went
straight to the dump. That is where the ones I had were going.
I kept a 465. I would have saved my last 453 as a spare, the one in
the picture, but I am just running out of room.
A guy I barely know from another newsgroup asked me if I was giving it
away somewhat facetiously and I said yes. He showed up at my door the
next day.

On Thu, 1 Apr 2021 20:14:02 -0600, lowbrowwoman, the endlessly driveling,
troll-feeding, senile idiot, blabbered again:


20 years ago or so Radio Shack had an o-scope probe to use with a
computer. The frequency range was limited by the processing power of the
day but it was handy for some things.

Yes, 20 years ago they had one! VBG

On Tuesday, March 30, 2021 at 5:19:06 PM UTC-4, wrote:
On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:
We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat

It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg
If you're unlucky enough to not have a variac, they're pretty easy to build, and no tedious winding of wire is involved.

See he

https://www.youtube.com/watch?v=P9UjxG8sN1c

In article ,
says...

For a real low cost solution you can use the computer's audio card and
free softwa

https://listoffreeware.com/best-free...tware-windows/


20 years ago or so Radio Shack had an o-scope probe to use with a
computer. The frequency range was limited by the processing power of the
day but it was handy for some things.



For around $ 200 to $ 300 Hantek makes some very good scopes. I have
one of them I bought several years ago. It is a 200 MHz version. I was
told at the time by several that the Hantek was the better one, but the
Rigol is also very good for the money.

I don't know if it is just hype, but some sources say to get one that is
sold in the US instead of ordering from China. Suppose to be a better
quality for the same model.

http://www.hantek.com/




Rigol is another China brand that has a good reputation for the same
price range.


https://www.rigolna.com/products/dig...loscopes/1000/

On Thu, 1 Apr 2021 20:14:02 -0600, rbowman posted for all of us to digest...


On 04/01/2021 12:37 PM, Tekkie? wrote:
I always wanted a scope but never got one. I was always interested in observing
the A/C waveform but I was afraid if I plugged in the inputs I would blow the
sucker up. A ham gave me one that weighed about 100lbs but had no leads. It sat
in my living room until my wife said to get rid of it. I built a Heathkit
automotive one which worked fine. Any recommendations?

https://www.electronics-lab.com/top-...inkers-makers/


For a real low cost solution you can use the computer's audio card and
free softwa

https://listoffreeware.com/best-free...tware-windows/


20 years ago or so Radio Shack had an o-scope probe to use with a
computer. The frequency range was limited by the processing power of the
day but it was handy for some things.

What does the bandwidth do/affect? I can assume from the pricing that more is
better and is there a good resource to learn how to use it? More questions to
follow, I'm sure.

--
Tekkie

On Thu, 01 Apr 2021 23:28:28 -0400, posted for all of us to
digest...


On Thu, 1 Apr 2021 14:37:33 -0400, Tekkie© wrote:


On Wed, 31 Mar 2021 21:51:47 -0400, posted for all of us to
digest...


On Wed, 31 Mar 2021 06:37:44 -0400, Pat
wrote:

On Tue, 30 Mar 2021 17:18:47 -0400, wrote:

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

After reading Dean Hoffman's suggestion, I did a little more research.
I didn't find much other than lots of warnings not to use generators.
Sub-zero didn't really say why, though. They did say that starting
both compressors could peak at 24 amps. But, since they recommend a
15 amp breaker, that peak can't last very long. Who knows what the
voltage would drop to at the compressors during that peak. Other than
duplicating your variac setup, the only thing I can think to try next
time is moving the battery/inverter to the kitchen to avoid some of
the voltage drop. The inverter claims 1500 watts continuous with 3000
watts peak. Sub-zero's stated 24 amps peak would very near that 3000
watts max, so what I measured at 114vac during a 800 watt load might
actually be much lower during that peak demand. We've lived here for
almost 20 years and that was the first power outage that lasted longer
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".

Thanks for your comments,
Pat

If you have access to a scope it might not be a bad idea to look at
the wave form under load. It might be pretty ugly.
My generator wasn't really that bad.

http://gfretwell.com/Propaneproject/Waveform.jpg

I always wanted a scope but never got one. I was always interested in observing
the A/C waveform but I was afraid if I plugged in the inputs I would blow the
sucker up. A ham gave me one that weighed about 100lbs but had no leads. It sat
in my living room until my wife said to get rid of it. I built a Heathkit
automotive one which worked fine. Any recommendations?

I would look for an old tektronics like that 453. They were built to
spec for IBM and real tanks. I don't think I ever saw a bad one and we
beat the hell out of them. I gave away 3 after they closed our office.
IBM must have dumped 10,000-15,000. Every 360/370 account had one and
a lot of CEs also had one in their car. I fear a lot of them went
straight to the dump. That is where the ones I had were going.
I kept a 465. I would have saved my last 453 as a spare, the one in
the picture, but I am just running out of room.
A guy I barely know from another newsgroup asked me if I was giving it
away somewhat facetiously and I said yes. He showed up at my door the
next day.

Beat me to it. The district had a 360. I wonder where that one went? I wonder
where a lot of interesting stuff went. Not to me. 8(

--
Tekkie

On Fri, 2 Apr 2021 10:37:49 -0400, Ralph Mowery posted for all of us to
digest...


In article ,
says...

For a real low cost solution you can use the computer's audio card and
free softwa

https://listoffreeware.com/best-free...tware-windows/


20 years ago or so Radio Shack had an o-scope probe to use with a
computer. The frequency range was limited by the processing power of the
day but it was handy for some things.



For around $ 200 to $ 300 Hantek makes some very good scopes. I have
one of them I bought several years ago. It is a 200 MHz version. I was
told at the time by several that the Hantek was the better one, but the
Rigol is also very good for the money.

I don't know if it is just hype, but some sources say to get one that is
sold in the US instead of ordering from China. Suppose to be a better
quality for the same model.

http://www.hantek.com/




Rigol is another China brand that has a good reputation for the same
price range.


https://www.rigolna.com/products/dig...loscopes/1000/

rbowman sent a link which I looked at and that had Hantek. I need more
information before I buy. Otherwise I just order the high price spread and
never use it...

I hate buying any China stuff - just as a personal philosophy but it seems
unavoidable.

Thanks

--
Tekkie

On Fri, 2 Apr 2021 05:34:56 -0700 (PDT), TimR
wrote:

On Tuesday, March 30, 2021 at 5:19:06 PM UTC-4, wrote:
On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:
We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat

It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg
If you're unlucky enough to not have a variac, they're pretty easy to build, and no tedious winding of wire is involved.

See he

https://www.youtube.com/watch?v=P9UjxG8sN1c
The "scariac" is NOT a variac - it is a high powered rheostat.
A Variac is a variable output autotransformer and can increase voltage
as well as fecrease it and the output voltage is pretty much unrelated
to the resistance of the load - unlike the "scariac" which is
basically part of a voltage devider network, dropping part of the
voltage across the load and dissipating the rest as heat in the
"cell". The "scariac" will also work on DC - while a Variac is
strictly AC. I have several rangng from 500ma to over 2a amps. I have
one set up in a toolbox that can supply up to 160 volts - either AC or
DC - from a 115 volt AC input and had another set up to supply
adjustable 240 from 115 or adjustable 115 from 240.

I also have a "sstepiac" - a buck-boost transformer which has a 6
and 12 volt secondary connected in series with the primary - either
forward or reversed - to boost or reduce the line voltage by 6, 12, or
18 volts depending on how it is configured - as well as an isolation
transformer made of parts of 2 microwave oven transformers. I used to
have an isolation trandformer made of 2 big fillament transformers
connected back to back for working on "ac/dc" tube radios and TVs
back when I was a kid.

A Variac is NOT an isolationtransformer - both sides of the line CAN
be "hot" on the output!!!!!

On Fri, 2 Apr 2021 10:37:49 -0400, Ralph Mowery
wrote:

In article ,
says...

For a real low cost solution you can use the computer's audio card and
free softwa

https://listoffreeware.com/best-free...tware-windows/


20 years ago or so Radio Shack had an o-scope probe to use with a
computer. The frequency range was limited by the processing power of the
day but it was handy for some things.



For around $ 200 to $ 300 Hantek makes some very good scopes. I have
one of them I bought several years ago. It is a 200 MHz version. I was
told at the time by several that the Hantek was the better one, but the
Rigol is also very good for the money.

I don't know if it is just hype, but some sources say to get one that is
sold in the US instead of ordering from China. Suppose to be a better
quality for the same model.

http://www.hantek.com/

Doubtfull as the US seller just buys them from the same place you buy
it from in China. The only "advantage" is possibly faster (but more
expensive) shipping and giving an American a bonus for (maybe) having
it in stock stateside. Here in Canada I can often get the stuff faster
from China directly instead of detouring it through the USA.



Rigol is another China brand that has a good reputation for the same
price range.


https://www.rigolna.com/products/dig...loscopes/1000/

On 04/02/2021 02:31 PM, Tekkie� wrote:
What does the bandwidth do/affect? I can assume from the pricing that more is
better and is there a good resource to learn how to use it? More questions to
follow, I'm sure.

Short answer, it determines the maximum frequency you can reliably
measure. More is not always better. The rule of thumb is the stated
bandwidth for a digital scope should be 5 times the frequency you're
interested in. For example the Atmel chips used in the Arduinos
typically are clocked at 8 or 16 MHz. The Z80 family, which still is one
of the most widely used processors for embedded systems, has a similar
range. A scope with 100 MHz bandwidth would be fine. 300 MHz and you
might see noise, harmonics, and so forth to confuse the issue.


https://www.tek.com/document/online/...loscope-basics

From the horse's mouth...

and the 12 minute version

https://www.youtube.com/watch?v=u4zyptPLlJI

Sparkfun is one of the more popular outlets for hobbyists:

https://www.sparkfun.com/

Adafruit is another

https://www.adafruit.com/

I've been playing around with one of these

https://www.adafruit.com/

using circuitPython. I've got a couple of the standard Arduinos that are
programmed with a C/C++ subset. There is an Arduino IDE and you can tie
it in with Visual Studio where with CircuitPython the interpreter is on
the device and all you need is a text editor.

What are you interested in doing? A 100 MHz scope is also adequate for
the ham HF bands or CBs.

On 04/02/2021 02:39 PM, Tekkie� wrote:
rbowman sent a link which I looked at and that had Hantek. I need more
information before I buy. Otherwise I just order the high price spread and
never use it...

First and most important question -- what do you want to do with it?
I've always worked mostly with digital circuitry so I bias that way.

I hate buying any China stuff - just as a personal philosophy but it seems
unavoidable.

I grew up not buying Japanese stuff since my brother spent his late
teens in the South Pacific. By the '80s bicycles, R/C models, and even
upscale fishing poles were cornered by the Japs.

By the '90s my brother visited in his RV towing the yacht tender. One of
the first things he said was 'I thought I would never buy a Japanese
car...' to explain the Toyota Tercel he was towing.

That's how it is with China. Back in the '80s I favored SunTour bike
components. They were a Japanese competitor to Shimano but lost the
market. I just took a ride tonight and the bike has SR SunTour
components -- same name but they're made in China not Osaka.

The West ****ed it all away. I don't know which models are involved but
there is a joke in the Triumph motorcycle circles about the new Thairumphs.

On Fri, 2 Apr 2021 20:24:08 -0600, lowbrowwoman, the endlessly driveling,
troll-feeding, senile idiot, blabbered again:


I grew up not buying Japanese stuff since my brother spent his late...

Oh, ****!!!

On Fri, 2 Apr 2021 20:08:28 -0600, lowbrowwoman, the endlessly driveling,
troll-feeding, senile idiot, blabbered again:

On 04/02/2021 02:31 PM, Tekkie� wrote:
What does the bandwidth do/affect? I can assume from the pricing that more is
better and is there a good resource to learn how to use it? More questions to
follow, I'm sure.

Short answer, it determines the maximum frequency you can reliably
measure. More is not always better. The rule of thumb is the stated
bandwidth for a digital scope should be 5 times the frequency you're
interested in. For example the Atmel chips used in the Arduinos
typically are clocked at 8 or 16 MHz. The Z80 family, which still is one
of the most widely used processors for embedded systems, has a similar
range. A scope with 100 MHz bandwidth would be fine. 300 MHz and you
might see noise, harmonics, and so forth to confuse the issue.

LOL You sure got that special talent to make ANYTHING you talk about appear
as obnoxious senile babble, senile blabbermouth.

On Fri, 2 Apr 2021 20:08:28 -0600, rbowman posted for all of us to digest...


On 04/02/2021 02:31 PM, Tekkie? wrote:
What does the bandwidth do/affect? I can assume from the pricing that more is
better and is there a good resource to learn how to use it? More questions to
follow, I'm sure.

Short answer, it determines the maximum frequency you can reliably
measure. More is not always better. The rule of thumb is the stated
bandwidth for a digital scope should be 5 times the frequency you're
interested in. For example the Atmel chips used in the Arduinos
typically are clocked at 8 or 16 MHz. The Z80 family, which still is one
of the most widely used processors for embedded systems, has a similar
range. A scope with 100 MHz bandwidth would be fine. 300 MHz and you
might see noise, harmonics, and so forth to confuse the issue.


https://www.tek.com/document/online/...loscope-basics

From the horse's mouth...

and the 12 minute version

https://www.youtube.com/watch?v=u4zyptPLlJI

Sparkfun is one of the more popular outlets for hobbyists:

https://www.sparkfun.com/

Adafruit is another

https://www.adafruit.com/

I've been playing around with one of these

https://www.adafruit.com/

using circuitPython. I've got a couple of the standard Arduinos that are
programmed with a C/C++ subset. There is an Arduino IDE and you can tie
it in with Visual Studio where with CircuitPython the interpreter is on
the device and all you need is a text editor.

What are you interested in doing? A 100 MHz scope is also adequate for
the ham HF bands or CBs.

The short answer is f'n around. I am also a ham...

--
Tekkie

On Fri, 2 Apr 2021 16:34:52 -0400, Tekkie© wrote:


On Thu, 01 Apr 2021 23:28:28 -0400, posted for all of us to
digest...


On Thu, 1 Apr 2021 14:37:33 -0400, Tekkie© wrote:


On Wed, 31 Mar 2021 21:51:47 -0400, posted for all of us to
digest...


On Wed, 31 Mar 2021 06:37:44 -0400, Pat
wrote:

On Tue, 30 Mar 2021 17:18:47 -0400, wrote:

On Tue, 30 Mar 2021 14:08:46 -0400, Pat
wrote:

We had a power outage here last Friday that lasted about 19 hours. (It
was caused by a wind storm blowing a large tree into power lines a few
blocks away). I happen to have four 100 Ah LiFePO4 12v batteries near
my circuit breaker box. (Their normal use is to power my boat during
the summer, but they were just being stored in the basement this time
of year). I also have a 1500 watt 12v to 120 VAC inverter. You can
probably see where this is going... Can I power my
refridgerator/freezer during the power outage using the inverter and
one of the 12v batteries? I thought, why not give it a try?

The refridgerator/freezer is a Sub-Zero brand built-in side-by-side
that is about 15 years old. If you aren't familiar with these, they
have separate systems for the refridgerator and freezer (ie, two
separate compressors). It has a dedicated 15 amp circuit, so it was
easy to pull the breaker and separate the wires from the breaker box.
I did that and then put a regular three prong plug on the end of the
wires and plugged the plug into the inverter socket and gave it a try.
The Sub-zero powered up normally and appeared to run. It drew about
800 watts for short periods and about 100 watts for longer periods.
(For example, 800 watts for 20 seconds followed by 100 watts for 2
minutes ... then repeat). So far, so good. After an hour or so, the
refridgerator section was back down to its normal 38 degrees F, but
the freezer temperature was slowly rising rather than dropping as
expected. Near the time the power was restored, the refridgerator
temp was still at 38F, but the freezer had risen from 0F to 22F. In
other words, the freezer wasn't really working at all. When the power
came back on, I restored the circuit to normal. Within a short time,
the freezer was back down to 0 and everything was back to normal.

So, my mystery is why did the refridgerator run normally off my
inverter but the freezer did not? The inverter is of the sine-wave
variety. I don't have a scope to look at the wave form, but it kept
the voltage up at 114 VAC even under the heaviest load (measured with
a Fluke 87). It was 120 VAC with no load. I would like to understand
this so I can use this setup during any future outages.

Thanks,
Pat


It is possible it just doesn't like 114v. That might be a bit lower
than that by the time it gets to the fridge. My generator puts out 115
under a fairly full load and my newer Whirlpool side by side didn't
like it much. The actual voltage at the plug was 109-110.
I ended up putting this together and it solved the problem.
When I ran it up to around 120 all was well.
http://gfretwell.com/electrical/Henc%20Variac.jpg

After reading Dean Hoffman's suggestion, I did a little more research.
I didn't find much other than lots of warnings not to use generators.
Sub-zero didn't really say why, though. They did say that starting
both compressors could peak at 24 amps. But, since they recommend a
15 amp breaker, that peak can't last very long. Who knows what the
voltage would drop to at the compressors during that peak. Other than
duplicating your variac setup, the only thing I can think to try next
time is moving the battery/inverter to the kitchen to avoid some of
the voltage drop. The inverter claims 1500 watts continuous with 3000
watts peak. Sub-zero's stated 24 amps peak would very near that 3000
watts max, so what I measured at 114vac during a 800 watt load might
actually be much lower during that peak demand. We've lived here for
almost 20 years and that was the first power outage that lasted longer
than a few hours. Other than quick glitches during lightning storms,
we have only had 2 or 3 outages in total over those 20 years. I'll
keep my eye out for a higher power inverter and plan to use it in the
kitchen rather than at the breaker box for "next time".

Thanks for your comments,
Pat

If you have access to a scope it might not be a bad idea to look at
the wave form under load. It might be pretty ugly.
My generator wasn't really that bad.

http://gfretwell.com/Propaneproject/Waveform.jpg

I always wanted a scope but never got one. I was always interested in observing
the A/C waveform but I was afraid if I plugged in the inputs I would blow the
sucker up. A ham gave me one that weighed about 100lbs but had no leads. It sat
in my living room until my wife said to get rid of it. I built a Heathkit
automotive one which worked fine. Any recommendations?

I would look for an old tektronics like that 453. They were built to
spec for IBM and real tanks. I don't think I ever saw a bad one and we
beat the hell out of them. I gave away 3 after they closed our office.
IBM must have dumped 10,000-15,000. Every 360/370 account had one and
a lot of CEs also had one in their car. I fear a lot of them went
straight to the dump. That is where the ones I had were going.
I kept a 465. I would have saved my last 453 as a spare, the one in
the picture, but I am just running out of room.
A guy I barely know from another newsgroup asked me if I was giving it
away somewhat facetiously and I said yes. He showed up at my door the
next day.

Beat me to it. The district had a 360. I wonder where that one went? I wonder
where a lot of interesting stuff went. Not to me. 8(

I lot of cool stuff came to my house. The guys were calling me for a
year after I left saying they were ready to throw out more stuff, did
I want to stop by. That was where I got the 2 of the 453s I gave away.
They had more. This place was like the fall of Saigon when IBM was
imploding, They didn't want to pay to ship anything back to Tampa or
Atlanta so it was "scrap locally".
One of the cool things I got was about 50 pounds of 3980 sorter parts.
(Rollers. chain sprockets, bearings, pillow blocks, pins etc). Pretty
handy stuff when you want to make anything with rotating machinery. I
also got a box of various SSRs. (3-30v in, controlling line voltage up
to 45a). Those are great to go straight from CMOS to big line powered
stuff. Plenty of cool test equipment that I was the last person who
could use.

On Fri, 2 Apr 2021 20:08:28 -0600, rbowman wrote:

On 04/02/2021 02:31 PM, Tekkie? wrote:
What does the bandwidth do/affect? I can assume from the pricing that more is
better and is there a good resource to learn how to use it? More questions to
follow, I'm sure.

Short answer, it determines the maximum frequency you can reliably
measure. More is not always better. The rule of thumb is the stated
bandwidth for a digital scope should be 5 times the frequency you're
interested in. For example the Atmel chips used in the Arduinos
typically are clocked at 8 or 16 MHz. The Z80 family, which still is one
of the most widely used processors for embedded systems, has a similar
range. A scope with 100 MHz bandwidth would be fine. 300 MHz and you
might see noise, harmonics, and so forth to confuse the issue.


https://www.tek.com/document/online/...loscope-basics

From the horse's mouth...

and the 12 minute version

https://www.youtube.com/watch?v=u4zyptPLlJI

Sparkfun is one of the more popular outlets for hobbyists:

https://www.sparkfun.com/

Adafruit is another

https://www.adafruit.com/

I've been playing around with one of these

https://www.adafruit.com/

using circuitPython. I've got a couple of the standard Arduinos that are
programmed with a C/C++ subset. There is an Arduino IDE and you can tie
it in with Visual Studio where with CircuitPython the interpreter is on
the device and all you need is a text editor.

What are you interested in doing? A 100 MHz scope is also adequate for
the ham HF bands or CBs.

You also care about rise time if you are looking at digital stuff.
Basically how fast does it respond to fast shots.