ITE Panel And burnt Quad Breakers

[B677]

Came across an ITE panel (20 Pace 40 circuit 200A) with three quads that are damaged due to heat on at least one leg. Worst one was EV breaker with 50A in middle and 20A on outsides - It started smoking when homeowner's EV charged at 9600 watts. The other one was combo of dryer and AC Condenser, and the third was induction cooktop with 20A/50A quad. The EV one heat damaged and it appears the socket/spring action was totally gone on one side and poor on the other (where the bus blade pushes into). The bus itself and the stabs are in decent shape considering its a mid 70s panel

Siemens is the correct breaker to use in this panel from what I understand ? I've only done a handful of Siemens panels - not as bad as GE but I don't like the breaker seating, usually feel loose.

So this was outside of the scope of the job - just did some investigating on the main panel after adding a heat pump outside - swapped out one Siemans and a two Bryant Quads for the customer as he picked them up. I recommend a panel swap to and exterior disconnect but I think they are tight on money.

Thinking one leg might be loose somewhere at main breaker or meter (aluminum feeders). Anyone have experience with Siemens/ITE - did the ITE have slightly thinner bus blades that might make a loose connection ? definitely seems like connection is loose and heat happens

 

[Fred B]

Can't speak to ITE vs Siemens but the ITE was also the maker for the Bulldog PushMatic panel. Can't say if the bus may have been thinner than the Siemens bus.
Are you talking about this type of breaker when you say "quad breaker" pictured below? Here it is called a 2 pole tandem. Is the metal binding clip still in place on the bus termination of the breaker? Seen guys remove the rejection device to make it fit a bus space that is not designed for tandem breakers, but that also keeps the breaker tighter onto the bus.

 

[Electromatic]

Having large, continuous loads on tandems or quads is not ideal as they can't dissipate the heat as well as full-sized breakers. If these are also packed above, below, and beside other big loads, the problem gets worse. There's probably no space for full-sized breakers, but you could try to reposition big loads apart from one another.
The loose fit on to the bus could be the result of the breakers overheating and relaxing the metal of the breaker contacts.

 

[B677]

Can't speak to ITE vs Siemens but the ITE was also the maker for the Bulldog PushMatic panel. Can't say if the bus may have been thinner than the Siemens bus.
Are you talking about this type of breaker when you say "quad breaker" pictured below? Here it is called a 2 pole tandem. Is the metal binding clip still in place on the bus termination of the breaker? Seen guys remove the rejection device to make it fit a bus space that is not designed for tandem breakers, but that also keeps the breaker tighter onto the bus.
View attachment 2578757

This is exactly the newer of the two I replaced - One older one that was heat damaged was a Bryant (also a quad / two pole tandem)

The binding clip you are referring to, I think I know what you mean - is it the binding clip part of the rejection mechanism ? So this clip does also provide some tension on the spot where the bus blade makes contact? This would explain a lot - on the the 15/20 the tension might not be so critical but now on the Quad when you have say 70A Total on that contact area that extra tension probably makes some difference.

Two pole tandem makes perfect sense but I have not referred to it as such - Quad to me means double tandem to me (four terminals)

The schematic on the panel shows 20 space 40 circuit - I have run into ITE/Siemans panels that did have the bus that would only allow tandems/quads in certain spaces - and the schematic on the panel would almost always show which spaces work with what. The last one I saw was back in June I believe it was a 12/24 where only half the panel could accept tandems - The ones than would accept tandems had the bus with notches

thanks for your input, very helpful

 

[B677]

Having large, continuous loads on tandems or quads is not ideal as they can't dissipate the heat as well as full-sized breakers. If these are also packed above, below, and beside other big loads, the problem gets worse. There's probably no space for full-sized breakers, but you could try to reposition big loads apart from one another.
The loose fit on to the bus could be the result of the breakers overheating and relaxing the metal of the breaker contacts.

I can only find these up to a combined max of 70A so I feel that shouldn't be bad - QO panels I think each bus blade is rated up to 125A - not familiar with Siemens

Edit : though looking at the bus blades made for tandems/quads : they are notched, so a tandem/quad compatible space has less conductive material than a space that won't accept tandems - seems ass-backwards ... unless that is why they seem to max out at 70A