Snag wrote:

Michael A. Terrell wrote:
Snag wrote:

Repeated tripouts on the thermal OL are BAD for compressors ! Not
to mention what might be happening in your breaker/fuse box . My
youngest had a bad cap in his condenser, repeated reset/trip cycles
fried the terminals/sockets/etc in his fuse box .He was faced with
a choice of power to the stove or power to the AC . Bad juju !!


Snag, some people will never learn to do things right. I've had two
electrical fires because people half assed repairs, or reused old
equipment that they should have thrown away. This property was bought
from the widow of a 'Precision fixedit' type that worked for the
schoolboard. He dragged home whatever he could from the scrap pile at
work to 'fix' things It's taken over 10 years to rip his crap out and
do proper repairs.

Actually this was original construction electrics . He has since had a
nice new breaker box installed . With capacity for expansion IIRC .



Good. I've seen too many caused by careless work, or where the lugs
had never been checked after the initial install. It ticks me off when
someone installs a panel with just enough circuits, or even one with a
couple less than they should have.


I caught one panel just before it would have gone up in flames. It
was a 200A 208 three phase panel that was too hot to touch, because the
clamps that held the incoming wire were loose. The insulation was burnt
back to the edge of the 4" conduit, and four new conductors had to be
pulled in, all the lugs replaced and rechecked a few times to take care
of the aluminum wire's cold flow. It had to be done between midnight &
4:00 AM, since it was the feed to a CATV headend. We had about 500
calls that their cable was out, even at that time of the night.

On Tue, 07 Aug 2012 18:13:24 -0500, Ignoramus25984
wrote:

On 2012-08-07, Michael A. Terrell wrote:

Ignoramus25984 wrote:

On 2012-08-07, Michael A. Terrell wrote:

Gunner Asch wrote:

Michael A. Terrell wrote:


Larry Jaques wrote:

Any thoughts, boys and girls?

I'd tell you what's wrong but you killfiled me, so tough luck!

ROFLMAO!!!


What goes around, comes around and can bite you in the ass.

So much for him telling me that I had nothing useful to say on the
group.

But did you actually have something useful to say about his air
conditioner?


I've walked other people through starting cap problems on this group.


So far, in this thread, you did not say anything useful.


Neither have you, that is't repeating what others have said.

I was the first to say that it was the capacitor.

And that's precisely what it appears to be. It's open resistively and
capicitaterly. I attempted to drain it with a 1Megohm resistor but
saw no spark, so I jumped with the pair of pliers. Nothing. Then I
used the VOM and found no farads around, nor ohms. Thank Crom!

--
Another belief of mine: that everyone else my age is an adult,
whereas I am merely in disguise.
-- Margaret Atwood

Larry Jaques wrote:

And that's precisely what it appears to be. It's open resistively and
capicitaterly. I attempted to drain it with a 1Megohm resistor but
saw no spark, so I jumped with the pair of pliers. Nothing. Then I
used the VOM and found no farads around, nor ohms. Thank Crom!


Why would an AC capacitor have a DC charge?

Michael A. Terrell wrote:
Snag wrote:

Michael A. Terrell wrote:
Snag wrote:

Repeated tripouts on the thermal OL are BAD for compressors ! Not
to mention what might be happening in your breaker/fuse box . My
youngest had a bad cap in his condenser, repeated reset/trip cycles
fried the terminals/sockets/etc in his fuse box .He was faced with
a choice of power to the stove or power to the AC . Bad juju !!


Snag, some people will never learn to do things right. I've had
two electrical fires because people half assed repairs, or reused
old equipment that they should have thrown away. This property was
bought from the widow of a 'Precision fixedit' type that worked for
the schoolboard. He dragged home whatever he could from the scrap
pile at work to 'fix' things It's taken over 10 years to rip his
crap out and do proper repairs.

Actually this was original construction electrics . He has since
had a nice new breaker box installed . With capacity for expansion
IIRC .



Good. I've seen too many caused by careless work, or where the lugs
had never been checked after the initial install. It ticks me off
when someone installs a panel with just enough circuits, or even one
with a couple less than they should have.


I caught one panel just before it would have gone up in flames. It
was a 200A 208 three phase panel that was too hot to touch, because
the clamps that held the incoming wire were loose. The insulation
was burnt back to the edge of the 4" conduit, and four new conductors
had to be pulled in, all the lugs replaced and rechecked a few times
to take care of the aluminum wire's cold flow. It had to be done
between midnight & 4:00 AM, since it was the feed to a CATV headend.
We had about 500 calls that their cable was out, even at that time of
the night.

The one on the back of my house was replaced a couple of years ago .
Original construction also , and the bus bars/breaker tabs were aluninum and
fried . The new one has a LOT of unused tabs ...
--
Snag
Learning keeps
you young !

On 2012-08-07, Stormin Mormon wrote:
Don't tell me I'm going to go blind,
and everyone will know?

You may go blind and your right hand will go blistery.

Snag wrote:

The one on the back of my house was replaced a couple of years ago .
Original construction also , and the bus bars/breaker tabs were aluninum and
fried . The new one has a LOT of unused tabs ...


You're a good man, no matter what the trolls say about ya!

On Monday, August 6, 2012 8:27:30 PM UTC-7, Larry Jaques wrote:
I just got back from Californy today, where I had a nice birthday

(59th) with family.



Home and shop A/C was working fine until about 6pm when I felt warm

air coming out of the vent.

Others have suggested compressor motor failure.
There's also loss of coolant, and frost blockage of cold coils.

So, to deal with frost blockage, give it a few hours OFF, watching
to see how much fluid comes out of the condensate lines. After it
starts melting, you can try fan-only operation for faster melting.

To deal with loss of coolant, takes a service call. Bad compressor,
bad motor, bad start capacitor... all take a service call (or lots of
homework, i.e. delay before birthday boy gets a cool night's sleep).

"Snag" wrote in message
...
Michael A. Terrell wrote:
Snag wrote:

Michael A. Terrell wrote:
Snag wrote:

Repeated tripouts on the thermal OL are BAD for compressors ! Not

Not according to Tecumseh.

The fact is that thermal disc type protection is engineered into the
compressor unit for EXACTLY the purpose of RELIABLY protecting the unit
despite the repeated occurance of abnormal conditions that oftentimes goes
on for years at a time.

http://www.tecumseh.com/en/canada/li...0Handbook.ashx

to mention what might be happening in your breaker/fuse box . My

Homeowner grade crap....can't recall for sure but thinking it was SQ D that
had a whole rash of those went bad a few years.

Oh and BTW, it's called a "disconnect"

youngest had a bad cap in his condenser, repeated reset/trip cycles

Except, the horse goes in FRONT of the cart...

fried the terminals/sockets/etc in his fuse box .He was faced with

Fried stab terminals at disconnect---voltage drop to unit---excessive
inrush = your capacitor will eventually fry.

a choice of power to the stove or power to the AC . Bad juju !!


Snag, some people will never learn to do things right. I've had
two electrical fires because people half assed repairs, or reused
old equipment that they should have thrown away. This property was
bought from the widow of a 'Precision fixedit' type that worked for

All I said was that putting a box fan on top will get someone by till it can
be fixed properly...

--that statement which I still stand by, and has absolutely nothing to do
with the rest of your horse **** above.

the schoolboard. He dragged home whatever he could from the scrap
pile at work to 'fix' things It's taken over 10 years to rip his
crap out and do proper repairs.

Actually this was original construction electrics . He has since
had a nice new breaker box installed . With capacity for expansion
IIRC .



Good. I've seen too many caused by careless work, or where the lugs
had never been checked after the initial install. It ticks me off
when someone installs a panel with just enough circuits, or even one
with a couple less than they should have.


I caught one panel just before it would have gone up in flames. It
was a 200A 208 three phase panel that was too hot to touch, because
the clamps that held the incoming wire were loose. The insulation
was burnt back to the edge of the 4" conduit, and four new conductors
had to be pulled in, all the lugs replaced and rechecked a few times
to take care of the aluminum wire's cold flow. It had to be done
between midnight & 4:00 AM, since it was the feed to a CATV headend.
We had about 500 calls that their cable was out, even at that time of
the night.

The one on the back of my house was replaced a couple of years ago .
Original construction also , and the bus bars/breaker tabs were aluninum
and fried . The new one has a LOT of unused tabs ...


Aluminum wire is notorious for deforming under the lugs due to thermal
cycling, ( which BTW is something which doesn't occur on motor startup
unless it's a LONG HARD START or it's already loose for some other reason )

A good idea is to tighten all lugs on a fairly regular basis, especially
those that run at near full load for long periods of time, such as electric
furnaces, clothes dryers and other resitstive loads.

FWIW, harbor freight has a relatively cheap handheld laser pointer /
thermometer that works pretty well if you're looking to find elevated
temperatures inside your electrical service equipment.

PrecisionmachinisT wrote:

The fact is that thermal disc type protection is engineered into the
compressor unit for EXACTLY the purpose of RELIABLY protecting the unit
despite the repeated occurance of abnormal conditions that oftentimes goes
on for years at a time.


Thermodiscs degrade over time. The contacts burn from the arc every
time they open, and the extra heat changes the constant of the spring
that casues them to trip. They often weld shut, after repeated trips.

"Larry Jaques" wrote in message
...
On Tue, 07 Aug 2012 17:01:21 -0500, Karl Townsend
wrote:


As long as the compressor runs, you can put a box fan on top of the unit
and get by...

You can get WAY more cooling using a garden hose and a spray nozzle.

'Taint running, so it's not just a high pressure switch shutting it
off when it overheats.

Good possibility it's a bad cap then.

--FWIW, what you are describing is the eaxct behaviour one expects to see
with a properly f\unctioning intermal thermal switch--otherwise, any time a
cap or fan went bad it would take the ****ing compressor out with it.

I pray it's a simple thing like just a cappy-
acitator.



You can check the cap with an older (analog) type ohm meter if you like...

Set it to the lowest range, and touch both leads to the cap...the needle
should swing one direction and then return to zero fairly quickly, if you
then reverse the leads, it should swing the opposite direction then return
to zero...

Otherwise, you poke around on the Bard site, there's pretty good
troubleshooting info there and since I don't feel like typing out detailed
instructions about how to check for failed compressor windings at the
moment...

http://www.bardhvac.com/digcat/volum...nfomanuals.pdf

That's a rather humble thing to write. I respect that.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Michael A. Terrell" wrote in message
m...

Stormin Mormon wrote:

Don't tell me I'm going to go blind, and everyone will know?


I can't speak for God.

"PrecisionmachinisT" wrote in
message

Good possibility it's a bad cap then.

You can check the cap with an older (analog) type ohm meter if you
like...
Set it to the lowest range, and touch both leads to the cap...the
needle should swing one direction and then return to zero fairly
quickly, if you then reverse the leads, it should swing the opposite
direction then return to zero...

The test may not work as well with a digital meter because they sample
too slowly. A more sensitive, but harder to interpret, test is to clip
a voltmeter across the cap, touch it briefly with a 9V battery and see
how slowly the reading decreases. I just tried it with an HF meter and
0.68 microfarad cap. With the cap the meter gives an intermediate
reading around 2-3V, without it the meter drops immediately to zero
after the battery is removed.

My good Keithley meter reads the HF meter's input resistance as 0.999
megohm on all the DC voltage ranges. Better meters might be 10 or 22
meg. A 1 microfarad cap with a 1 megohm load will lose about 2/3 of
its voltage every second, i.e. 10V, 3V, 1V, 0.3V, 0.1V. That's not
precisely accurate, but neither are commercial-grade capacitors.
http://www.tpub.com/neets/book2/3d.htm

jsw

I've tested capacitors with analog ohm meter, but that isn't what I remember
happening.

Christopher A. Young
Learn more about Jesus
www.lds.org
..


You can check the cap with an older (analog) type ohm meter if you
like...
Set it to the lowest range, and touch both leads to the cap...the
needle should swing one direction and then return to zero fairly
quickly, if you then reverse the leads, it should swing the opposite
direction then return to zero...

Michael A. Terrell wrote:
Why would an AC capacitor have a DC charge?

Because the "switch" opened when the voltage across it wasn't zero?
This is a series cap, isn't it? I.e., no path to discharge once the
switch opens.

An AC cap always has charge on it, except at the AC zero crossing.

I'd have to check some day. But, I'm guessing that the connection to the cap
has continutity. And, a run cap will always be zero charge when removed from
the circuit.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Bob Engelhardt" wrote in message
...
Michael A. Terrell wrote:
Why would an AC capacitor have a DC charge?

Because the "switch" opened when the voltage across it wasn't zero?
This is a series cap, isn't it? I.e., no path to discharge once the
switch opens.

An AC cap always has charge on it, except at the AC zero crossing.

Stormin Mormon wrote:
I'd have to check some day. But, I'm guessing that the connection to the cap
has continutity.

What do you mean?

And, a run cap will always be zero charge when removed from the circuit.

Why? I was trying to say that it will almost always have charge,
depending upon when exactly the circuit is opened. (Assuming that it's
in series.)

Think about it: cap's conduct AC current in that the charge goes into
them and out of them sinusoidally. But the charge doesn't go through
them. It goes on and off one side and the other side alternately.
There is always some charge on the capacitor while running. When the
circuit is opened, the charge at that moment stays there.

Bob

BTW - I clipped the quotes including my post that you were replying to
because your top posting screws up the quoting sequence/tree.

Bob Engelhardt wrote:

Michael A. Terrell wrote:
Why would an AC capacitor have a DC charge?

Because the "switch" opened when the voltage across it wasn't zero?
This is a series cap, isn't it? I.e., no path to discharge once the
switch opens.

An AC cap always has charge on it, except at the AC zero crossing.


It's in a low Q, low impedance circuit. A lot of start caps have a
bleeded inside, or welded to the terminals.

Bob Engelhardt wrote:

Stormin Mormon wrote:
I'd have to check some day. But, I'm guessing that the connection to the cap
has continutity.

What do you mean?

And, a run cap will always be zero charge when removed from the circuit.

Why? I was trying to say that it will almost always have charge,
depending upon when exactly the circuit is opened. (Assuming that it's
in series.)

Think about it: cap's conduct AC current in that the charge goes into
them and out of them sinusoidally. But the charge doesn't go through
them. It goes on and off one side and the other side alternately.
There is always some charge on the capacitor while running. When the
circuit is opened, the charge at that moment stays there.


Why? That would make the item dangerous to service. Maybe fatal.
I've worked on equipment that had a 'Shorting Stick' along with HV
interlocks, in case the high resistance bleeder resistors failed. A 3
KVDC supply that can supply a 1,000 amp discharge current doesn't give
you a second chance.

These aren't storage capacitors, they are used to give a phase
shift. High AC current for a few cycles, then unused till the next
start cycle. Run caps are similar, but much lower capacitance.

If they didn't have the built in bleeders, there would be a lot of
injured or dead HVAC types.

"Jim Wilkins" wrote in message
...
"PrecisionmachinisT" wrote in message

Good possibility it's a bad cap then.

You can check the cap with an older (analog) type ohm meter if you
like...
Set it to the lowest range, and touch both leads to the cap...the needle
should swing one direction and then return to zero fairly quickly, if you
then reverse the leads, it should swing the opposite direction then
return to zero...

The test may not work as well with a digital meter because they sample too
slowly. A more sensitive, but harder to interpret, test is to clip a
voltmeter across the cap, touch it briefly with a 9V battery and see how
slowly the reading decreases. I just tried it with an HF meter and 0.68
microfarad cap. With the cap the meter gives an intermediate reading
around 2-3V, without it the meter drops immediately to zero after the
battery is removed.

My good Keithley meter reads the HF meter's input resistance as 0.999
megohm on all the DC voltage ranges. Better meters might be 10 or 22 meg.
A 1 microfarad cap with a 1 megohm load will lose about 2/3 of its voltage
every second, i.e. 10V, 3V, 1V, 0.3V, 0.1V. That's not precisely
accurate, but neither are commercial-grade capacitors.
http://www.tpub.com/neets/book2/3d.htm


I try not to think too much about why it doesn't work with the digital
meters, just that it's a pretty reliable test for figuring out if the
capacitpr is open or shorted, which is one of the reasons I probably will
always keep them around.

Another thing I like them for is checkomg motor windings for
continuity--many of the digital meters lack the required accuracy in the low
ranges and so they don't work well if you're trying to differentiate between
a dead short and say 4 ohms or so.

"PrecisionmachinisT" wrote in
message

Another thing I like them for is checkomg motor windings for
continuity--many of the digital meters lack the required accuracy in
the low ranges and so they don't work well if you're trying to
differentiate between a dead short and say 4 ohms or so.

That's a continuing annoyance with my HF meter. The ohms zero can be
20 ohms until I wiggle whichever connection was bad, usually the
banana jacks in the meter.

If you want to measure winding resistance accurately, force about an
Amp through it and measure the voltage drop. At 1A, 1 mV is one
milliOhm.

"mike" wrote in message ...
On 8/7/2012 1:52 PM, Michael A. Terrell wrote:




What are you doing here with a troll email address? STUPID!!!

Enlighten me.
What's a troll email address?



Any other questions ?

On Wed, 08 Aug 2012 12:37:40 -0400, Jim Wilkins wrote:

"PrecisionmachinisT" wrote in
message

Another thing I like them for is checkomg motor windings for
continuity--many of the digital meters lack the required accuracy in
the low ranges and so they don't work well if you're trying to
differentiate between a dead short and say 4 ohms or so.

That's a continuing annoyance with my HF meter. The ohms zero can be
20 ohms until I wiggle whichever connection was bad, usually the
banana jacks in the meter.

If you want to measure winding resistance accurately, force about an Amp
through it and measure the voltage drop. At 1A, 1 mV is one milliOhm.

Yes. A Kelvin connection. It is very useful.

http://en.wikipedia.org/wiki/Four-terminal_sensing

--Winston

"Winston" wrote in message ...
On Wed, 08 Aug 2012 12:37:40 -0400, Jim Wilkins wrote:

"PrecisionmachinisT" wrote in
message

Another thing I like them for is checkomg motor windings for
continuity--many of the digital meters lack the required accuracy in
the low ranges and so they don't work well if you're trying to
differentiate between a dead short and say 4 ohms or so.

That's a continuing annoyance with my HF meter. The ohms zero can be
20 ohms until I wiggle whichever connection was bad, usually the
banana jacks in the meter.

If you want to measure winding resistance accurately, force about an Amp
through it and measure the voltage drop. At 1A, 1 mV is one milliOhm.

Yes. A Kelvin connection. It is very useful.

http://en.wikipedia.org/wiki/Four-terminal_sensing




My old Triplet 630 seems to work just fine for this and since the "B" cell only needs replacement about once every 30 years......

On Wed, 08 Aug 2012 11:44:59 -0700, PrecisionmachinisT wrote:

"Winston" wrote in message
...
On Wed, 08 Aug 2012 12:37:40 -0400, Jim Wilkins wrote:

(...)

If you want to measure winding resistance accurately, force about an
Amp through it and measure the voltage drop. At 1A, 1 mV is one
milliOhm.

Yes. A Kelvin connection. It is very useful.

http://en.wikipedia.org/wiki/Four-terminal_sensing




My old Triplet 630 seems to work just fine for this and since the "B"
cell only needs replacement about once every 30 years......

That's peachy for getting a 'ballpark' idea and probably quite sufficient
for most motor servicing without the need of a Kelvin connection.

When you *do* need much better precision and accuracy, a Kelvin
connection with a good digital meter is hard to beat. In a previous
lifetime, I was able to estimate current flow in a very low impedance
application by using a measured PCB trace as my current shunt. 'Worked a
treat.

--Winston

If you pull the two wires off the cap. (power off, of course.) Put an ohm
meter on those two wires, they will probably have continuity.

When you turn off the power to the device, the electric fields in the motor
all collapse. And, the cap is left hooked to a short (through the motor
windings). So, regardless of when you shut off the power, the moment the
power goes off, the cap discharges through the wires.

I'll admit, I've not turned off a motor, and pulled the cap and checked for
continuity. But, I'm guessing I'm right.

Thanks for trimming text.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Bob Engelhardt" wrote in message
...
Stormin Mormon wrote:
I'd have to check some day. But, I'm guessing that the connection to the
cap
has continutity.

What do you mean?

And, a run cap will always be zero charge when removed from the circuit.

Why? I was trying to say that it will almost always have charge,
depending upon when exactly the circuit is opened. (Assuming that it's
in series.)

Think about it: cap's conduct AC current in that the charge goes into
them and out of them sinusoidally. But the charge doesn't go through
them. It goes on and off one side and the other side alternately.
There is always some charge on the capacitor while running. When the
circuit is opened, the charge at that moment stays there.

Bob

BTW - I clipped the quotes including my post that you were replying to
because your top posting screws up the quoting sequence/tree.

Winston wrote:

PrecisionmachinisT wrote:

My old Triplet 630 seems to work just fine for this and since the "B"
cell only needs replacement about once every 30 years......

That's peachy for getting a 'ballpark' idea and probably quite sufficient
for most motor servicing without the need of a Kelvin connection.

When you *do* need much better precision and accuracy, a Kelvin
connection with a good digital meter is hard to beat. In a previous
lifetime, I was able to estimate current flow in a very low impedance
application by using a measured PCB trace as my current shunt. 'Worked a
treat.


The company name is Triplett, not Triplet: http://www.triplett.com

I've used a fixed current into a shorted trace, and a 4.5 digit DVM
to locate the short. Let's see him do that with an analog meter like
that Triplett, when the voltage change was a couple hundredths of a volt
from one point to the next.

They were OK meters in tube type radio & TV repair, 50 years ago.
The 630 was usually the meter pictured in early solid state repair
manuals ('60s) telling you not to use, to keep from destroying
transistors & signal diodes.

PrecisionmachinisT wrote:

My old Triplet 630 seems to work just fine for this and since the "B" cell only needs replacement about once every 30 years......


It's perfect, if you never do any precision work....

It has two 'Batteries', B1 & B2.

B1 is 30 Volts (NEDA 210) which costs about $40 these days.
B2 is 1.5 Volts


Not suprising that you don't know the difference.

PrecisionmachinisT wrote:

I try not to think too much about why it doesn't work with the digital
meters, just that it's a pretty reliable test for figuring out if the
capacitpr is open or shorted, which is one of the reasons I probably will
always keep them around.


DVMs use a constant current to read resistance.

Another thing I like them for is checkomg motor windings for
continuity--many of the digital meters lack the required accuracy in the low
ranges and so they don't work well if you're trying to differentiate between
a dead short and say 4 ohms or so.


Lack accuracy on the low ranges. What a joke. It has more
resolution that a cheap analog meter. They show you the poor contact
resistance, along with the resistance of the meter leads. Let's see you
find a shorted turn with that antique Triplett.

PrecisionmachinisT wrote:

"mike" wrote in message ...
On 8/7/2012 1:52 PM, Michael A. Terrell wrote:




What are you doing here with a troll email address? STUPID!!!

Enlighten me.
What's a troll email address?



Any other questions ?


No, that covers it.

Stormin Mormon wrote:
...
When you turn off the power to the device, the electric fields in the motor
all collapse. And, the cap is left hooked to a short (through the motor
windings). So, regardless of when you shut off the power, the moment the
power goes off, the cap discharges through the wires.
....

A run-capacitor motor has the cap in series with the winding. When
power is shut off, there is no path to discharge the cap. Only if the
cap were in parallel with the winding, would it be discharged as you
say. But then it wouldn't phase-shift the winding current.

Michael A. Terrell wrote:
PrecisionmachinisT wrote:

I try not to think too much about why it doesn't work with the
digital meters, just that it's a pretty reliable test for figuring
out if the capacitpr is open or shorted, which is one of the reasons
I probably will always keep them around.


DVMs use a constant current to read resistance.

Another thing I like them for is checkomg motor windings for
continuity--many of the digital meters lack the required accuracy in
the low ranges and so they don't work well if you're trying to
differentiate between a dead short and say 4 ohms or so.


Lack accuracy on the low ranges. What a joke. It has more
resolution that a cheap analog meter. They show you the poor contact
resistance, along with the resistance of the meter leads. Let's see
you find a shorted turn with that antique Triplett.

Heh , I use a cheap RS digital meter with a type K thermocouple to track
temps in my aluminum melts . Voltages are in the range of 20-30 millivolts
.... which my analog meter won't even twitch at .
--
Snag
Learning keeps
you young !

On 8/8/2012 2:00 PM, Michael A. Terrell wrote:

PrecisionmachinisT wrote:

wrote in message ...
On 8/7/2012 1:52 PM, Michael A. Terrell wrote:




What are you doing here with a troll email address? STUPID!!!

Enlighten me.
What's a troll email address?



Any other questions ?


No, that covers it.
Yep, I got a question on how that applies to me and makes me STUPID!!!?

Michael A. Terrell wrote:
Bob Engelhardt wrote:
....
When the
circuit is opened, the charge at that moment stays there.

Why? That would make the item dangerous to service. Maybe fatal.

"Why?" Because it's the physics. The physics doesn't care if it's
dangerous.

I've worked on equipment that had a 'Shorting Stick' along with HV
interlocks, in case the high resistance bleeder resistors failed. ...

These aren't storage capacitors, they are used to give a phase
shift. ...

They don't function as storage capacitors, but they can store charge.
Why are there bleeders and back-up shorting sticks? - because the
circuit can open with charge/voltage on the cap.

If they didn't have the built in bleeders, there would be a lot of
injured or dead HVAC types.

My comments have been more conceptual, my not being very familiar with
motor cap technology. I have never said that there weren't bleeders,
only that the motor could stop with a charge on the cap.

I have a collection of motor caps in my parts box. I randomly picked 6
and charged them to 100v. After 1-1/2 hours, 2 of them still had
significant charge: 1 97v & the other 99.

Bob

"Winston" wrote in message
...
On Wed, 08 Aug 2012 11:44:59 -0700, PrecisionmachinisT wrote:

"Winston" wrote in message
...
On Wed, 08 Aug 2012 12:37:40 -0400, Jim Wilkins wrote:

(...)

If you want to measure winding resistance accurately, force about
an
Amp through it and measure the voltage drop. At 1A, 1 mV is one
milliOhm.

Yes. A Kelvin connection. It is very useful.
http://en.wikipedia.org/wiki/Four-terminal_sensing

My old Triplet 630 seems to work just fine for this and since the
"B"
cell only needs replacement about once every 30 years......

That's peachy for getting a 'ballpark' idea and probably quite
sufficient
for most motor servicing without the need of a Kelvin connection.

When you *do* need much better precision and accuracy, a Kelvin
connection with a good digital meter is hard to beat. In a previous
lifetime, I was able to estimate current flow in a very low
impedance
application by using a measured PCB trace as my current shunt.
'Worked a
treat.

--Winston

I have a nice calibrated lab milliOhm sitting in front of me. I doubt
a Triplett can show it's actually 0.6 microOhms over.

jsw

On Wednesday, August 8, 2012 1:55:28 PM UTC-7, Michael Terrell wrote:
PrecisionmachinisT wrote:



My old Triplet 630 seems to work just fine for this and since the "B" cell only needs replacement about once every 30 years......

It has two 'Batteries', B1 & B2.



B1 is 30 Volts (NEDA 210) which costs about $40 these days.

B2 is 1.5 Volts

The nomenclature has changed. Old-style radios had an A battery (like your D cell, 1.5V)
for the filaments, B battery (30V) suitable for biasing vacuum tube grids, and C battery
for the plate supply.

It was a real technological stretch when Motorola made a 6V automobile radio set...

Snag wrote:

Michael A. Terrell wrote:
PrecisionmachinisT wrote:

I try not to think too much about why it doesn't work with the
digital meters, just that it's a pretty reliable test for figuring
out if the capacitpr is open or shorted, which is one of the reasons
I probably will always keep them around.


DVMs use a constant current to read resistance.

Another thing I like them for is checkomg motor windings for
continuity--many of the digital meters lack the required accuracy in
the low ranges and so they don't work well if you're trying to
differentiate between a dead short and say 4 ohms or so.


Lack accuracy on the low ranges. What a joke. It has more
resolution that a cheap analog meter. They show you the poor contact
resistance, along with the resistance of the meter leads. Let's see
you find a shorted turn with that antique Triplett.

Heh , I use a cheap RS digital meter with a type K thermocouple to track
temps in my aluminum melts . Voltages are in the range of 20-30 millivolts
... which my analog meter won't even twitch at.


I recently won three separate auction for Fluke 8050A meters on Ebay,
and repaired two of them. The third has a bad custom microprocessor, but
I spent under $100 for all three. They are 4.5 digit, but I'd love to
have a couple 5.5 digit that would let you read fractions of a millivolt
change.

mike wrote:

On 8/8/2012 2:00 PM, Michael A. Terrell wrote:

PrecisionmachinisT wrote:

wrote in message ...
On 8/7/2012 1:52 PM, Michael A. Terrell wrote:




What are you doing here with a troll email address? STUPID!!!

Enlighten me.
What's a troll email address?



Any other questions ?

No, that covers it.

Yep, I got a question on how that applies to me and makes me STUPID!!!?


OK. First of all is the Gmail domain. Then 'spamme9' clinches it.
Hotmail is another huge source of trolls.

A lot of people filter out all traffic from those domains. Happy,
now?

Bob Engelhardt wrote:

Michael A. Terrell wrote:
Bob Engelhardt wrote:
...
When the
circuit is opened, the charge at that moment stays there.

Why? That would make the item dangerous to service. Maybe fatal.

"Why?" Because it's the physics. The physics doesn't care if it's
dangerous.

I've worked on equipment that had a 'Shorting Stick' along with HV
interlocks, in case the high resistance bleeder resistors failed. ...

These aren't storage capacitors, they are used to give a phase
shift. ...

They don't function as storage capacitors, but they can store charge.
Why are there bleeders and back-up shorting sticks? - because the
circuit can open with charge/voltage on the cap.

If they didn't have the built in bleeders, there would be a lot of
injured or dead HVAC types.

My comments have been more conceptual, my not being very familiar with
motor cap technology. I have never said that there weren't bleeders,
only that the motor could stop with a charge on the cap.

I have a collection of motor caps in my parts box. I randomly picked 6
and charged them to 100v. After 1-1/2 hours, 2 of them still had
significant charge: 1 97v & the other 99.


Then you shouldn't play with them till you learn how to do it
safely. Not all can capacitors are motor capacitors. Some are used as
filter capacitors, or coupling capacitors. You didn't put a bleeder
across them to make it a fair test, as well.

whit3rd wrote:

On Wednesday, August 8, 2012 1:55:28 PM UTC-7, Michael Terrell wrote:
PrecisionmachinisT wrote:



My old Triplet 630 seems to work just fine for this and since the "B" cell only needs replacement about once every 30 years......

It has two 'Batteries', B1 & B2.



B1 is 30 Volts (NEDA 210) which costs about $40 these days.

B2 is 1.5 Volts

The nomenclature has changed. Old-style radios had an A battery (like your D cell, 1.5V)
for the filaments, B battery (30V) suitable for biasing vacuum tube grids, and C battery
for the plate supply.


Sigh. I started working on 'antique' radios in the '60s.

A = Filaments
B = Plate voltage
C = Bias supply, which quickly disappeared when they learned to self
bias tubes.

It was a real technological stretch when Motorola made a 6V automobile radio set...


As opposed to a 32 volt farm radio powered by a large wet cell
battery and charged by a Wincharger?

Here is a 6V Motorola vibrator power supply in my collection:
http://home.earthlink.net/~mike.terrell/IA142.jpg

I found a few wiring diagrams here;
http://www.brighthubengineering.com/...on-run-motors/

From the quick glance, it sure looks like if you disconnect the AC, that
there is motor windings across the cap.

Do you have a wiring diagram online I can see? I could easily be mistaken.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Bob Engelhardt" wrote in message
...
Stormin Mormon wrote:
...
When you turn off the power to the device, the electric fields in the
motor
all collapse. And, the cap is left hooked to a short (through the motor
windings). So, regardless of when you shut off the power, the moment the
power goes off, the cap discharges through the wires.
....

A run-capacitor motor has the cap in series with the winding. When
power is shut off, there is no path to discharge the cap. Only if the
cap were in parallel with the winding, would it be discharged as you
say. But then it wouldn't phase-shift the winding current.