I have an electrical panel with Square D breakers.
They are duals, (2 breakers in one) 20 Amps each.
One breaker is tripping from time to time for no reason that I can see and I
want to replace it to see if that solves the problem. (I know I can swap
two identical breakers to see what happens but read on....)
I see Cuttler Hammer dual breakers for sale on Ebay at a low price, makes it
not worth the time to swap them..
Are the mechanical mounting and electrical connections standardized so that
I can use Cutler Hammer breakers in a panel with Square D's?
I know I need to match the electrical ratings...
Because it sounds like the panel in question is almost barely not
overloaded... So if the panel is overpopulated it isn't that much of
a stretch of the imagination that an individual circuit in such a
panel is not likewise over capacity or suffering from voltage drop
due to a longer run with a smaller incorrectly sized wire...
And aside from those words, what sense does the rest of it make?
It's a long leap that because the guy says his panel has half size
breakers it means that it's overloaded and that is causing the
problem. I'd give the OP some credit for having the sense to
rule that out. It's also not clear that all the breakers are half
size, he could just mean the one in question is.
In 40 years as an electrician, I get many calls where the customer has a
tripping circuit breaker. It is very rare when the cause is a defective
breaker. I will say, if the OP has Homeline split circuit breakers (half
size 20-20) type, I've had instances where I've seen those breakers trip
from vibrations near the panel
Bingo! I love it when they plug it into the battery backup power supply.
I wind up fixing a computer that's been fed dirty power, repairing or
replacing the battery backup unit and or associated power strips that
have melted. Oh look, a receptacle, I can plug in my 1500 watt ceramic
heater and keep my legs warm! o_O
Umm, no they are not, there are very few interchangeable
circuit breakers out there... Circuit breakers are made
to work with certain panels only, the ones they are
listed for... There is much more to it than the amperage
rating of the over current protection on the breaker...
The busbars in different panels are different sizes and
thicknesses and spacings, therefore the socket that
the various breakers have to accommodate the busbars
in the panels they are listed for use in varies depending
on the manufacturer and panel model line type...
Using an incorrect breaker for a panel might not be
obvious as it will "sorta fit" but won't line up properly
with the cutout in the panel cover, won't be in the
proper amount of contact with the busbar and might
not "clamp" into the panel properly...
Some questions for you are:
-- How many actual circuits are there in your panel ?
It sounds like you are pushing maximum occupancy
limits if you have double-breakers (two circuits in a
single-pole single space unit) in your panel...
-- Have you verified that the circuit is not in fact
The breaker might be working perfectly and tripping
because of an overload condition even though you
aren't aware that one is occurring...
-- Is one of the circuits in the double-breaker used
close to its amperage capacity on a regular basis ?
Those neat-o double-breakers can get hot when they
are used under full load constantly, and with twice
the heat from twice the number of circuits inside
the same space normally occupied by one breaker
device, the smaller components of the two breaker
mechanisms are more susceptible to being deformed
under high load high heat conditions...
Your problem could even be from an overloaded
circuit in an adjacent breaker which has malfunctioned
and failed to trip which is causing one of the two circuits
inside the double-breaker to nuisance trip from overheating...
re: "I see Cuttler Hammer dual breakers for sale on Ebay at a low
price, makes it not worth the time to swap them."
Huh? How long does it take to loosen 2 screws, swap the wires from one
breaker to another and tighten the screws up again?
You could probably do that in less time than it takes to place the
order on eBay.
swap the two wires on two breakers and see if the failure follows the
wire swap or follows the breaker. it is only two screws for heaven's
sake. If you do need a new breaker, take your old one with you to
make sure you get exactly the same shape/mounting,. Every
manufacturer has many various breakers, they change from time to time
due to NEC changes and apparently identical breakers may in fact not
be identical. The store should be able to cross-reference from your
defective breaker to current production if you need a new one. You
don't say how old the breakers are..
In many cases a breaker of a different brand will work just fine.
It will not pass an electrical inspection, at least not here, because the
breakers and the box are rated based on a single brand.
Sometimes the rating standard is exactly the same and it would pass, but the
inspectors take the easy way out. I sorta understand that. Inspecting each
breaker's ratings would be a PITA.
If it looks the same, mounts the same, has the same amperage and fits the
hole in the cover most likely you will be safe using it.
Specific to tandem breakers is the lockout method that prevents too many of
them being in the same box. It might be a hook or nubs on the side. Best
thing is to take the old one with you to the BORG and find an exact match
based on physical size and amps. The local Lowes carries CH breakers, the
Murrys and some of the GE as well as the Homeline are about the same.
There are some really old CH ones that are no longer made. That panel
should be replaced completely as it was recalled.
Please come visit http://www.househomerepair.com
There is one exception to another brand of breaker in a panel failing
electrical inspection. Underwriters Recognized (UR) breakers will
pass inspection if the inspector is competent. The UR mark means that
Underwriters Laboratories has Recognized that breaker as suitable for
use in a panel of another brand and that it will meet the minimum
standards for that size and type of breaker in that use. At one time
Thomas & Betts made several such breakers but I don't believe that
they still do.
There is an exception to the breaker of a different manufacturer not
passing electrical inspection. If the breaker of a different
manufacturer is Classified for use in that panel board it will pass
inspection if the inspector is competent.
[QUOTE]98. Classified and Listed Compatibility List - A circuit
breaker that is both Classified and
Listed is marked on the side with the statement:
"This circuit breaker is Listed for use in circuit breaker enclosures
and panelboards intended and
marked for its use. This circuit breaker is Classified for use, where
the available short-circuit current
is 10 kA, 120/240 V ac or less, in the compatible panelboards shown in
Publication No. ______
provided with this circuit breaker. When used as a Classified circuit
breaker, do not use in
equipment connected to circuits having an available system short-
circuit current in excess of 10 kA,
120/240 V ac. If additional information is necessary, contact
[Classified circuit breaker
As one example many of the Cutler Hammer breakers are Classified for
use in other manufacturers panels.
the situation is a home not commercial, it's not MY home.
the breaker in question that trips from time to time feeds the gas
furnace, nothing else
when I go to check things out, I can start and stop the furnace and
blower many times and the breaker doesn't trip. I don't see anything
out of sorts in the furnace. No wires rubbing on sheet metal etc. I
have some experience with things electrical.
A week or so goes by and the breaker will have tripped.
The breaker may be getting old and tripping on the start up surge of
The panal has Square D dual style breakers. Its been that way since
the house was built.
Throwing a "new" ebay breaker in there to see what happens is the
easiest as long as its <$10 or so.
So I sould have asked two questions?
1) Will a Cuttler Hammer Breaker FIT and WORK in a Sqaure D panal?
2) Is it legal?
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