Generator electric question
 

A little off topic, but I know someone here will have the answer. I have a
genset with a 220v recepticle which I wire into a transfer switch. The only
circuit that actually uses 220 serves the well-pump. The transfer switch
has a ganged 20amp breaker, which I wired to the well-pump circuit. The
generator, however, has two 20amp pushbutton circuit breakers, one for each
leg of 110. My question is: If one of the generator breakers tripped, then
my well pump would be getting only one leg of 110. Would the increased load
on the ganged breaker on the transfer switch cause it to also trip, or
should I wire in a ganged breaker at the generator itself? I certainly
don't want or have a way to test this...so I'm looking for advice.
Thanks,
Nok

Generator electric question
 

Nok wrote:

A little off topic, but I know someone here will have the answer. I have a
genset with a 220v recepticle which I wire into a transfer switch. The only
circuit that actually uses 220 serves the well-pump. The transfer switch
has a ganged 20amp breaker, which I wired to the well-pump circuit. The
generator, however, has two 20amp pushbutton circuit breakers, one for each
leg of 110. My question is: If one of the generator breakers tripped, then
my well pump would be getting only one leg of 110. Would the increased load
on the ganged breaker on the transfer switch cause it to also trip, or
should I wire in a ganged breaker at the generator itself? I certainly
don't want or have a way to test this...so I'm looking for advice.


If either breaker opens the well pump won't run. There would be a
lower load on the generator, without the pump. The breaker that's going
to trip is the one with an additional load, so you'll notice that the
pump isn't running.


--
You can't have a sense of humor, if you have no sense.

Generator electric question
 

With one 120 VAC breaker open (at the generator), the well
should stop running, and the amp draw would go to zero. Much
like opening a switch.

The ganged breaker is for people / worker safety. So, when
one turns off the (double) breaker to the well pump, one
turns off ALL the power.

If one side was off, like your generator 120 vac (single)
breaker example. The well pump would stop. A worker might
think the power is off. But, winding, and wires would still
have power available, and would be a safety hazzard for
workers.

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


"Nok" wrote in message
...
A little off topic, but I know someone here will have the
answer. I have a
genset with a 220v recepticle which I wire into a transfer
switch. The only
circuit that actually uses 220 serves the well-pump. The
transfer switch
has a ganged 20amp breaker, which I wired to the well-pump
circuit. The
generator, however, has two 20amp pushbutton circuit
breakers, one for each
leg of 110. My question is: If one of the generator
breakers tripped, then
my well pump would be getting only one leg of 110. Would
the increased load
on the ganged breaker on the transfer switch cause it to
also trip, or
should I wire in a ganged breaker at the generator itself?
I certainly
don't want or have a way to test this...so I'm looking for
advice.
Thanks,
Nok

Generator electric question
 

"some" other appliances in the house would work. The ones on
the still-not leg. Other appliances, on the tripped leg,
would not work. Very possible that the generator would still
be under load.

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


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

If either breaker opens the well pump won't run. There
would be a
lower load on the generator, without the pump. The breaker
that's going
to trip is the one with an additional load, so you'll notice
that the
pump isn't running.


--
You can't have a sense of humor, if you have no sense.

Generator electric question
 

On 10/25/2011 3:48 PM, Stormin Mormon wrote:
With one 120 VAC breaker open (at the generator), the well
should stop running, and the amp draw would go to zero. Much
like opening a switch.
....

"Should"???

How can it do anything else; there's no return leg any longer.

--

Generator electric question
 

Stormin Mormon wrote:

"some" other appliances in the house would work. The ones on
the still-not leg. Other appliances, on the tripped leg,
would not work. Very possible that the generator would still
be under load.


Not if both breakers are accurate. The well pump loads both sides,
and one breaker by itself. The other breaker will have a higher load
and should trip first, if the load is more than a few tens of mA. He
could always add a small double pole breaker box and a 240 V 20A breaker
like those for a pump or small A/C to get common trip. Connect it to
the line side of the existing breakers.


--
You can't have a sense of humor, if you have no sense.

Generator electric question
 

On Oct 25, 4:48*pm, "Stormin Mormon"
wrote:
With one 120 VAC breaker open (at the generator), the well
should stop running, and the amp draw would go to zero. Much
like opening a switch.

The ganged breaker is for people / worker safety. So, when
one turns off the (double) breaker to the well pump, one
turns off ALL the power.

If one side was off, like your generator 120 vac (single)
breaker example. The well pump would stop. A worker might
think the power is off. But, winding, and wires would still
have power available, and would be a safety hazzard for
workers.

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

Zowie! twice in one day, I'm agreeing with Stormin. The dual ganged
breaker is there to ensure that if either side trips, that there is no
power in the box. That's for the purpose of protecting the
electrician, not the equipment.

I'd spend the money on a good GFCI (which has nothing to do with your
well pump, but I've seen plenty of generator installations that are an
electrocution waiting to happen).

Generator electric question
 

Sorry, Nanny. I'll write it out a hundred times, now.

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


"dpb" wrote in message
...
On 10/25/2011 3:48 PM, Stormin Mormon wrote:
With one 120 VAC breaker open (at the generator), the well
should stop running, and the amp draw would go to zero.
Much
like opening a switch.
....

"Should"???

How can it do anything else; there's no return leg any
longer.

--

Generator electric question
 

On 10/25/2011 03:55 PM, dpb wrote:
On 10/25/2011 3:48 PM, Stormin Mormon wrote:
With one 120 VAC breaker open (at the generator), the well
should stop running, and the amp draw would go to zero. Much
like opening a switch.
...

"Should"???

How can it do anything else; there's no return leg any longer.

Some power will still flow through the motor. The path is 120V
from the still hot leg, through the motor, through all of the
120V loads (in parallel) on the tripped leg, and thence to the
neutral. The fraction of the 120V that appears across the motor
depends on the ratio of the motor impedance to that of those
paralleled loads. In any event, current through the motor
cannot be higher than the sum of the currents those 120V loads
would normally draw.

--
Bob Nichols AT comcast.net I am "RNichols42"

Generator electric question
 

On 10/25/2011 4:13 PM, Michael A. Terrell wrote:

Stormin Mormon wrote:

"some" other appliances in the house would work. The ones on
the still-not leg. Other appliances, on the tripped leg,
would not work. Very possible that the generator would still
be under load.


Not if both breakers are accurate. The well pump loads both sides,
and one breaker by itself. The other breaker will have a higher load
and should trip first, if the load is more than a few tens of mA. He
could always add a small double pole breaker box and a 240 V 20A breaker
like those for a pump or small A/C to get common trip. Connect it to
the line side of the existing breakers.




Ain't gonna happen, Mike.

Manufacturing tolerance will decide which breaker goes first....

Generator electric question
 

On 10/25/2011 3:55 PM, dpb wrote:
On 10/25/2011 3:48 PM, Stormin Mormon wrote:
With one 120 VAC breaker open (at the generator), the well
should stop running, and the amp draw would go to zero. Much
like opening a switch.
...

"Should"???

How can it do anything else; there's no return leg any longer.

--


The electrical _potential_ is still there even if there is no current flow.

Wanna know which breaker let go?

Touch one of the lines.


OR think of it this way.

Pee on an electric fence - once.
Just once is all it will take.

Generator electric question
 

Richard wrote:

On 10/25/2011 4:13 PM, Michael A. Terrell wrote:

Stormin Mormon wrote:

"some" other appliances in the house would work. The ones on
the still-not leg. Other appliances, on the tripped leg,
would not work. Very possible that the generator would still
be under load.


Not if both breakers are accurate. The well pump loads both sides,
and one breaker by itself. The other breaker will have a higher load
and should trip first, if the load is more than a few tens of mA. He
could always add a small double pole breaker box and a 240 V 20A breaker
like those for a pump or small A/C to get common trip. Connect it to
the line side of the existing breakers.



Ain't gonna happen, Mike.

Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.


--
You can't have a sense of humor, if you have no sense.

Generator electric question
 

On 10/26/2011 1:50 AM, Michael A. Terrell wrote:

Richard wrote:

On 10/25/2011 4:13 PM, Michael A. Terrell wrote:

Stormin Mormon wrote:

"some" other appliances in the house would work. The ones on
the still-not leg. Other appliances, on the tripped leg,
would not work. Very possible that the generator would still
be under load.


Not if both breakers are accurate. The well pump loads both sides,
and one breaker by itself. The other breaker will have a higher load
and should trip first, if the load is more than a few tens of mA. He
could always add a small double pole breaker box and a 240 V 20A breaker
like those for a pump or small A/C to get common trip. Connect it to
the line side of the existing breakers.



Ain't gonna happen, Mike.

Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.



Sorry, thought that was the OP...

Generator electric question
 

Richard wrote:

On 10/26/2011 1:50 AM, Michael A. Terrell wrote:

Richard wrote:

On 10/25/2011 4:13 PM, Michael A. Terrell wrote:

Stormin Mormon wrote:

"some" other appliances in the house would work. The ones on
the still-not leg. Other appliances, on the tripped leg,
would not work. Very possible that the generator would still
be under load.


Not if both breakers are accurate. The well pump loads both sides,
and one breaker by itself. The other breaker will have a higher load
and should trip first, if the load is more than a few tens of mA. He
could always add a small double pole breaker box and a 240 V 20A breaker
like those for a pump or small A/C to get common trip. Connect it to
the line side of the existing breakers.



Ain't gonna happen, Mike.

Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.



Sorry, thought that was the OP...


No problem. :)


--
You can't have a sense of humor, if you have no sense.

Generator electric question
 

I guess you didn't know? 220 VAC motors typically do not
have a neutral connection.

Since in a 220 VAC motor, the two 120 VAC legs are in
series, the current (amperage) is the same. Doesn't add to
make a higher number.

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


"Robert Nichols"
wrote in
message ...

How can it do anything else; there's no return leg any
longer.

Some power will still flow through the motor. The path is
120V
from the still hot leg, through the motor, through all of
the
120V loads (in parallel) on the tripped leg, and thence to
the
neutral. The fraction of the 120V that appears across the
motor
depends on the ratio of the motor impedance to that of those
paralleled loads. In any event, current through the motor
cannot be higher than the sum of the currents those 120V
loads
would normally draw.

--
Bob Nichols AT comcast.net I am "RNichols42"

Generator electric question
 

On Wed, 26 Oct 2011 09:36:15 -0400, "Stormin Mormon"
wrote:

I guess you didn't know? 220 VAC motors typically do not
have a neutral connection.

Since in a 220 VAC motor, the two 120 VAC legs are in
series, the current (amperage) is the same. Doesn't add to
make a higher number.

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

If you didn't follow the verbal explanationm, draw the circuit,
including the 120V loads.

The path is
120V
from the still hot leg, through the motor, through all of
the
120V loads (in parallel) on the tripped leg, and thence to
the
neutral.

--
Ned Simmons

Generator electric question
 

Ned Simmons wrote:
On Wed, 26 Oct 2011 09:36:15 -0400, "Stormin Mormon"
wrote:

I guess you didn't know? 220 VAC motors typically do not
have a neutral connection.

Since in a 220 VAC motor, the two 120 VAC legs are in
series, the current (amperage) is the same. Doesn't add to
make a higher number.

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

If you didn't follow the verbal explanationm, draw the circuit,
including the 120V loads.

The path is
120V
from the still hot leg, through the motor, through all of
the
120V loads (in parallel) on the tripped leg, and thence to
the
neutral.

Kinda like when I see a car comin' at me with one very dim headlight . I
know right away that it's very likely that dim bulb has lost it's connection
to ground .
--
Snag
I think there might
be a pun in there ...

Generator electric question
 

On 10/26/2011 08:36 AM, Stormin Mormon wrote:
I guess you didn't know? 220 VAC motors typically do not
have a neutral connection.

Since in a 220 VAC motor, the two 120 VAC legs are in
series, the current (amperage) is the same. Doesn't add to
make a higher number.

Care to point out where I said there was any neutral connection to
the motor? If there are some 120V loads on the leg with the
tripped breaker (which is quite likely, since that's the breaker
that tripped), there is a path from that side of the motor
_through_those_loads_ to the neutral conductor. Now you have a
voltage divider from the still hot 120V line, through the motor,
and the parallel combination of those 120V loads. The motor will
see a portion of the 120V, and those other loads will see the
rest. (Yes, I know the voltages will be partly out of phase and
won't add arithmetically. Trying to keep it simple here.)

--
Bob Nichols AT comcast.net I am "RNichols42"

Generator electric question
 

"Michael A. Terrell" wrote:



Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.


With ANYBODY's breakers. Especially cheap thermal magnetic ones.

The tolerance bands are typically +/- 10%.
And that is assuming they work at all.

jk

Generator electric question
 

On 10/25/2011 1:21 PM, Nok wrote:
A little off topic, but I know someone here will have the answer. I have a
genset with a 220v recepticle which I wire into a transfer switch. The only
circuit that actually uses 220 serves the well-pump. The transfer switch
has a ganged 20amp breaker, which I wired to the well-pump circuit. The
generator, however, has two 20amp pushbutton circuit breakers, one for each
leg of 110. My question is: If one of the generator breakers tripped, then
my well pump would be getting only one leg of 110. Would the increased load
on the ganged breaker on the transfer switch cause it to also trip, or
should I wire in a ganged breaker at the generator itself? I certainly
don't want or have a way to test this...so I'm looking for advice.
Thanks,
Nok


Not knowing what type of a well and pump you are referring to, it's a
little hard to respond.

The two deep wells on my properties, 350 ft and 650 ft, both use
submersible pumps towards the bottoms of each well. They run off 220
volts and have NO connection to either a ground or common component of
the 220 power.

In fact, any connection to ground immediately pops the circuit breakers.
That means the wire feeding the pump has shorted to the pipe. I know
this from bad experiences!

So, if either side of your generator 220 opens up, the pump won't run.

If you are running a shallow well pump, then I can't answer.

Paul

Generator electric question
 

On Wed, 26 Oct 2011 21:52:34 -0700, jk wrote:

"Michael A. Terrell" wrote:



Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.


With ANYBODY's breakers. Especially cheap thermal magnetic ones.

The tolerance bands are typically +/- 10%.
And that is assuming they work at all.

jk

I should stick in a bit of information here about breakers. One of the
common types readily avaible are Murrey breakers.

They suck badly. Ive had to replace 22 of them this year in an
installation thats only 3 yrs old.

Burned contacts at the base of the breaker, along with breakers that
trip far far too easily.

After this year..Im going with SquareD in all my installs. Murrey was
cheaper..but the amortized costs are more, both in hardware and down
time.

Shrug

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

Generator electric question
 

Is this generator supplying loads other than the pump? Single phase loads?

Even if the pump is the only load, good luck ensuring that the downstream
ganged breaker will trip first. If there are other loads (between the two
breakers), a gen breaker will almost certainly trip first.

What happens next will depend on what lies downstream of the (tripped) gen
breaker. Single phase loads on the tripped phase will end up in series with
the pump winding. While the voltage will probably collapse so that these
loads become inoperative, that leg will still be energized at some voltage.
If there's a fault there (what tripped the breaker), that could lead to a
hazardous situation.

Best bet is to replace the two gen breakers with a ganged unit. Don't feed a
line to line load from independent single pole breakers.

--
Paul Hovnanian
------------------------------------------------------------------
Shoot low, sheriff. They're riding Shetlands!

Generator electric question
 

On Sat, 29 Oct 2011 14:31:59 -0700, Gunner Asch
wrote:

On Wed, 26 Oct 2011 21:52:34 -0700, jk wrote:

"Michael A. Terrell" wrote:



Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.

You can get the "aircraft style" 2-pole handle-tie lever breakers that
will work fine in that portable generator - replace the two little
pop-button style breakers.

There are Line Lug - Load Lug US Style breakers available that can be
panel-mounted - GE, Square-D and others. But they're huge in
comparison, they won't fit.

With ANYBODY's breakers. Especially cheap thermal magnetic ones.

The tolerance bands are typically +/- 10%.
And that is assuming they work at all.

jk

I should stick in a bit of information here about breakers. One of the
common types readily avaible are Murrey breakers.

They suck badly. Ive had to replace 22 of them this year in an
installation thats only 3 yrs old.

Burned contacts at the base of the breaker, along with breakers that
trip far far too easily.

After this year..Im going with SquareD in all my installs. Murrey was
cheaper..but the amortized costs are more, both in hardware and down
time.

The new Murray MP series aren't that bad, and I deal with them every
day in residences and retail...

But if you're dealing with industrial shops, they really should be
installing Bolt-On Panelboards and breakers, they won't have those
buss problems because it's clamped on with a 10-32 screw. You can get
them Square-D QOB Bolt-On panels if you insist on staying with them.

When given a choice I always stay with a 1" "Industrial Interchange"
style that is interchangeable in an emergency - you can stick a
Cutler/Challenger or GE in a Murray panel in a pinch, or vice versa.

Stay away from Square-D Homeline, they are NOT true I.I. style and you
have to modify the Homeline buss with side-cutters to get a Murray or
GE breaker in, Pool Men do that to me all the time because they have a
Murray breaker with them. But snipping a chunk out of the Aluminum
buss breaks the tin plating and speeds up the "Self-Destruct Tin
Corrosion" feature, and I'll soon be installing a whole new panel.

You can get Square D QO now, but eventually they will be discontinued
in favor of the Homeline and then the fun starts.

GE is good but I won't put them in new, they have proprietary breaker
stabs on their 'skinnys' and there's a cross-bar where a regular
Murray or Challenger 'thick' won't plug in. You have to go get a GE
breaker - but again the Pool Men just start snipping off the side
cross-bars to get a Challenger that they have with them in, see above.

And the Aluminum buss stabs in any brand panel WILL fail after 20 or
30 years if they aren't treated right - like the builders that sprayed
Wallboard Texture into all the open panels in the development, and
then their Electricians doing trim-out just stuffed the breakers on
over the gypsum splatters. Twenty years later, the panels start
burning up...

Put an Aluminum Buss panel anywhere near salt water, and that's more
like 5 to 15 years.

Half of that you can blame on cheap people, even if you can order the
panel with a Copper Buss option most people won't pay extra for one.

You want trouble, the older Challenger Half-size split breakers with
the "hook" buss stabs - they don't have a pressure spring, so they get
stretched real easy and get loose on the buss stab, then start burning
up the stabs.

Same thing with Zinsco breakers, especially the skinny little stabs on
the R38 and RC38 twins.

And don't get me started on FPE Stab-Lok - sending 200 Amps through an
8-32 Screw to the vertical buss, and their miniature stabs that don't
stay stabbed or locked into the busses. And the 2-pole breakers that
fail and get jammed internally and then will not open for anything -
even a roaring fire. FPE is Bad Juju, Replace The Whole Panel at the
first hint of trouble.

-- Bruce --

Generator electric question
 

Gunner Asch wrote:

On Wed, 26 Oct 2011 21:52:34 -0700, jk wrote:

"Michael A. Terrell" wrote:



Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.


With ANYBODY's breakers. Especially cheap thermal magnetic ones.

The tolerance bands are typically +/- 10%.
And that is assuming they work at all.

jk

I should stick in a bit of information here about breakers. One of the
common types readily avaible are Murrey breakers.

They suck badly. Ive had to replace 22 of them this year in an
installation thats only 3 yrs old.

Burned contacts at the base of the breaker, along with breakers that
trip far far too easily.

After this year..Im going with SquareD in all my installs. Murrey was
cheaper..but the amortized costs are more, both in hardware and down
time.


Murray was interchangable with a lot of other brands.

American Switch
Arrow-Hart Bryant
Crouse Hinds
Cutler-Hammer
Electri-Center
Frank Adams
General Electric
General Switch
Gould
GTE Sylvania
Montgomery Ward
Murray
Siemens
Westinghouse/Bryant

Sears had a series that fit at one time, as well.


A lot of breakers and panels are shipped with little or no ontact
lubricant, which causes early failures. Some 'electricians' wipe it off
the buss bars, causing their own problems.

http://ecatalog.squared.com/pubs/Cir...0600DB0109.pdf

--
You can't have a sense of humor, if you have no sense.

Generator electric question
 

On Sun, 30 Oct 2011 01:24:49 -0400, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

On Wed, 26 Oct 2011 21:52:34 -0700, jk wrote:

"Michael A. Terrell" wrote:



Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.


With ANYBODY's breakers. Especially cheap thermal magnetic ones.

The tolerance bands are typically +/- 10%.
And that is assuming they work at all.

jk

I should stick in a bit of information here about breakers. One of the
common types readily avaible are Murrey breakers.

They suck badly. Ive had to replace 22 of them this year in an
installation thats only 3 yrs old.

Burned contacts at the base of the breaker, along with breakers that
trip far far too easily.

After this year..Im going with SquareD in all my installs. Murrey was
cheaper..but the amortized costs are more, both in hardware and down
time.


Murray was interchangable with a lot of other brands.

American Switch
Arrow-Hart Bryant
Crouse Hinds
Cutler-Hammer
Electri-Center
Frank Adams
General Electric
General Switch
Gould
GTE Sylvania
Montgomery Ward
Murray
Siemens
Westinghouse/Bryant

Sears had a series that fit at one time, as well.


A lot of breakers and panels are shipped with little or no ontact
lubricant, which causes early failures. Some 'electricians' wipe it off
the buss bars, causing their own problems.

http://ecatalog.squared.com/pubs/Cir...0600DB0109.pdf


Ive gotten stab slot burns..badly smoking the base of the breakers and
often breaking the shells of the breakers around the stab slots. The
stabs themselves are eroded and rough with pits and burns.

And the breakers have never tripped..so its not a result of an overload.

The only thing I can think of..is salt air..but its a couple miles
inland from the Pacific and nothing else shows any signs of salt
corrosion.

These breakers are only 20 amp, 3ph and are carrying about 8 amps under
load..with less than 18 amps on startup..everything is running under
VFDs.

And Im ****ed off as I cant figure out why this is happening. And its
only happening with the new Murray panels. Nothing at all with the old
SquareDs and other old weird brands that Ive not swapped out yet.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

Generator electric question
 

Gunner Asch wrote:

On Sun, 30 Oct 2011 01:24:49 -0400, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

On Wed, 26 Oct 2011 21:52:34 -0700, jk wrote:

"Michael A. Terrell" wrote:



Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.


With ANYBODY's breakers. Especially cheap thermal magnetic ones.

The tolerance bands are typically +/- 10%.
And that is assuming they work at all.

jk

I should stick in a bit of information here about breakers. One of the
common types readily avaible are Murrey breakers.

They suck badly. Ive had to replace 22 of them this year in an
installation thats only 3 yrs old.

Burned contacts at the base of the breaker, along with breakers that
trip far far too easily.

After this year..Im going with SquareD in all my installs. Murrey was
cheaper..but the amortized costs are more, both in hardware and down
time.


Murray was interchangable with a lot of other brands.

American Switch
Arrow-Hart Bryant
Crouse Hinds
Cutler-Hammer
Electri-Center
Frank Adams
General Electric
General Switch
Gould
GTE Sylvania
Montgomery Ward
Murray
Siemens
Westinghouse/Bryant

Sears had a series that fit at one time, as well.


A lot of breakers and panels are shipped with little or no ontact
lubricant, which causes early failures. Some 'electricians' wipe it off
the buss bars, causing their own problems.

http://ecatalog.squared.com/pubs/Cir...0600DB0109.pdf

Ive gotten stab slot burns..badly smoking the base of the breakers and
often breaking the shells of the breakers around the stab slots. The
stabs themselves are eroded and rough with pits and burns.

And the breakers have never tripped..so its not a result of an overload.

The only thing I can think of..is salt air..but its a couple miles
inland from the Pacific and nothing else shows any signs of salt
corrosion.

These breakers are only 20 amp, 3ph and are carrying about 8 amps under
load..with less than 18 amps on startup..everything is running under
VFDs.

And Im ****ed off as I cant figure out why this is happening. And its
only happening with the new Murray panels. Nothing at all with the old
SquareDs and other old weird brands that Ive not swapped out yet.


Westinghouse used to make the circuit breakers for a lot of other
brands, including the lower current Sqaure D breakers. I knew a Polish
EE who worked for Square D at a plant in Ohio where they made large
switchgear. BTW, he told the WORST polish jokes! :)

They were made in the US. Where are the failing Murray breakers
made? Mexico or China?


--
You can't have a sense of humor, if you have no sense.

Generator electric question
 

On Sun, 30 Oct 2011 04:48:03 -0700, Gunner Asch
wrote:

Ive gotten stab slot burns..badly smoking the base of the breakers and
often breaking the shells of the breakers around the stab slots. The
stabs themselves are eroded and rough with pits and burns.

And the breakers have never tripped..so its not a result of an overload.

The only thing I can think of..is salt air..but its a couple miles
inland from the Pacific and nothing else shows any signs of salt
corrosion.

These breakers are only 20 amp, 3ph and are carrying about 8 amps under
load..with less than 18 amps on startup..everything is running under
VFDs.

And Im ****ed off as I cant figure out why this is happening. And its
only happening with the new Murray panels. Nothing at all with the old
SquareDs and other old weird brands that Ive not swapped out yet.

Gunner

I'm betting a big part of this is from the VFD's - they might be
"officially" drawing 18A startup and 8A run, but the chopper effect of
the drives throws a ton of harmonics that your regular clamp-amp can't
see on the power lines and the neutral buss.

The other half of the problem is the tin-plated aluminum busses in
the Murray panel - "When they are good they are very very good, but
when they are bad they are rotten."

Once the tin coating is compromised the aluminum underneath starts
corroding, and it'll run the whole length but you can't see it easily
under the tin. Till it gets peeled off, then.... Eew.

I have a Two Strikes policy - When you go there the first time and
have to shut off power, pull all the breakers, inspect and clean all
the stabs with Noalox and abandon one or two as hopelessly burnt, you
warn them that next time the panel has to get changed.

If it happens again, you have to stand firm or soon it will get so bad
they'll have you back weekly, and worse they'll claim you are
incompetent - pull the panel and put in a fresh one.

Even if the customer claims poverty and insist you "patch it again" -
don't offer the choice if it's really bad. Their just being a cheap
ass, some Millionaires do that as a reflex thinking they're saving
money when they really aren't. And I don't want to keep dicking with
the same damn problem a dozen times.

Effects of high Q-factor harmonics are very visible if you do a
thermal scan of the panels at any large office building - computer
power supplies are switching style also, and the Q Factor (Inductive
reactance) from all those harmonics means they have to put in special
panels with a way oversized Neutral Bar and conductor back to the
transformer.

And the step-down 480-120 transformers for computer-heavy office
buildings have to be specially built ("Q-13" or higher markings) to
damp the harmonics too, or they start glowing at the Neutral
connections.

This shop might need the same rework to address that many VFD's
concentrated on one panel. That, and check into adding power factor
capacitors and filter inductors in front of each machine to try and
stop the crap at the source.

Last time I dealt with this was a bank that burned up the neutral buss
in a 125A sub-panel - I put in a new 200A neutral buss to get them
running again, and warned them they need to buy a better class of
computers and/or get an Electrical Engineer involved.

-- Bruce --

Generator electric question
 

On Sun, 30 Oct 2011 08:40:35 -0400, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

On Sun, 30 Oct 2011 01:24:49 -0400, "Michael A. Terrell"
wrote:


Gunner Asch wrote:

On Wed, 26 Oct 2011 21:52:34 -0700, jk wrote:

"Michael A. Terrell" wrote:



Manufacturing tolerance will decide which breaker goes first....


Sure, with Chinese breakers. :)

That's why I sugessted adding the external dual pole breaker with
common trip.


With ANYBODY's breakers. Especially cheap thermal magnetic ones.

The tolerance bands are typically +/- 10%.
And that is assuming they work at all.

jk

I should stick in a bit of information here about breakers. One of the
common types readily avaible are Murrey breakers.

They suck badly. Ive had to replace 22 of them this year in an
installation thats only 3 yrs old.

Burned contacts at the base of the breaker, along with breakers that
trip far far too easily.

After this year..Im going with SquareD in all my installs. Murrey was
cheaper..but the amortized costs are more, both in hardware and down
time.


Murray was interchangable with a lot of other brands.

American Switch
Arrow-Hart Bryant
Crouse Hinds
Cutler-Hammer
Electri-Center
Frank Adams
General Electric
General Switch
Gould
GTE Sylvania
Montgomery Ward
Murray
Siemens
Westinghouse/Bryant

Sears had a series that fit at one time, as well.


A lot of breakers and panels are shipped with little or no ontact
lubricant, which causes early failures. Some 'electricians' wipe it off
the buss bars, causing their own problems.

http://ecatalog.squared.com/pubs/Cir...0600DB0109.pdf

Ive gotten stab slot burns..badly smoking the base of the breakers and
often breaking the shells of the breakers around the stab slots. The
stabs themselves are eroded and rough with pits and burns.

And the breakers have never tripped..so its not a result of an overload.

The only thing I can think of..is salt air..but its a couple miles
inland from the Pacific and nothing else shows any signs of salt
corrosion.

These breakers are only 20 amp, 3ph and are carrying about 8 amps under
load..with less than 18 amps on startup..everything is running under
VFDs.

And Im ****ed off as I cant figure out why this is happening. And its
only happening with the new Murray panels. Nothing at all with the old
SquareDs and other old weird brands that Ive not swapped out yet.


Westinghouse used to make the circuit breakers for a lot of other
brands, including the lower current Sqaure D breakers. I knew a Polish
EE who worked for Square D at a plant in Ohio where they made large
switchgear. BTW, he told the WORST polish jokes! :)

They were made in the US. Where are the failing Murray breakers
made? Mexico or China?

I cant recall. I think..think heco en Mexico


One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

Generator electric question
 

On Sun, 30 Oct 2011 08:30:16 -0700, "Bruce L. Bergman (munged human
readable)" wrote:

On Sun, 30 Oct 2011 04:48:03 -0700, Gunner Asch
wrote:

Ive gotten stab slot burns..badly smoking the base of the breakers and
often breaking the shells of the breakers around the stab slots. The
stabs themselves are eroded and rough with pits and burns.

And the breakers have never tripped..so its not a result of an overload.

The only thing I can think of..is salt air..but its a couple miles
inland from the Pacific and nothing else shows any signs of salt
corrosion.

These breakers are only 20 amp, 3ph and are carrying about 8 amps under
load..with less than 18 amps on startup..everything is running under
VFDs.

And Im ****ed off as I cant figure out why this is happening. And its
only happening with the new Murray panels. Nothing at all with the old
SquareDs and other old weird brands that Ive not swapped out yet.

Gunner

I'm betting a big part of this is from the VFD's - they might be
"officially" drawing 18A startup and 8A run, but the chopper effect of
the drives throws a ton of harmonics that your regular clamp-amp can't
see on the power lines and the neutral buss.

The other half of the problem is the tin-plated aluminum busses in
the Murray panel - "When they are good they are very very good, but
when they are bad they are rotten."

Once the tin coating is compromised the aluminum underneath starts
corroding, and it'll run the whole length but you can't see it easily
under the tin. Till it gets peeled off, then.... Eew.

I have a Two Strikes policy - When you go there the first time and
have to shut off power, pull all the breakers, inspect and clean all
the stabs with Noalox and abandon one or two as hopelessly burnt, you
warn them that next time the panel has to get changed.

If it happens again, you have to stand firm or soon it will get so bad
they'll have you back weekly, and worse they'll claim you are
incompetent - pull the panel and put in a fresh one.

Even if the customer claims poverty and insist you "patch it again" -
don't offer the choice if it's really bad. Their just being a cheap
ass, some Millionaires do that as a reflex thinking they're saving
money when they really aren't. And I don't want to keep dicking with
the same damn problem a dozen times.

Effects of high Q-factor harmonics are very visible if you do a
thermal scan of the panels at any large office building - computer
power supplies are switching style also, and the Q Factor (Inductive
reactance) from all those harmonics means they have to put in special
panels with a way oversized Neutral Bar and conductor back to the
transformer.

And the step-down 480-120 transformers for computer-heavy office
buildings have to be specially built ("Q-13" or higher markings) to
damp the harmonics too, or they start glowing at the Neutral
connections.

This shop might need the same rework to address that many VFD's
concentrated on one panel. That, and check into adding power factor
capacitors and filter inductors in front of each machine to try and
stop the crap at the source.

Last time I dealt with this was a bank that burned up the neutral buss
in a 125A sub-panel - I put in a new 200A neutral buss to get them
running again, and warned them they need to buy a better class of
computers and/or get an Electrical Engineer involved.

-- Bruce --

Good advise saved and noted!!

Thanks Bruce!

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch