Various breakers in same panel.

[powerplay]

Aside from warranty, are there safety issues with installing cutler hammer and westinghouse breakers into an Siemens panel? I know many interchange some, but when I ran into an obviously retrofitted panel with assorted breakers do I I insist they replace all breakers with matching ones before the new owner buys? (I suspect yes)

 

[templdl]

Are the breakers and/or panel listed for such us? If not as a professional you shouldn't assume and do it.
Even though it would be your professional observation that the installation looks secure the question remains is it UL listed. And as a professional with knowledge of the NEC does it comply with that which is included in ART 110 of the NEC?
And, what about your liability? Should some catastrophic failure occur you may be blamed being ant easy and obvious target. The question is, is it worth it?

 

[Jraef]

It's a weird little marketing game that they all play now, and it pits professionals against the DIY crowd in my opinion. I used to work for Siemens, this was how they explained it internally to us.

Breakers can be UL listed for use in panels made by other mfrs, because all you have to do is buy one of their panels and test your breakers in it, typically just one of each frame size that it can accept. So if Siemens wants to list their Type Q breakers in a GE, C-H or Sq. D Homeline panel, it's relatively cheap for them to do so. That way when John Q Public goes down to Home Despot and buys a blister-packed "Universal" breaker he can get the cheapest thing he can find and it will stab in.

But LOAD CENTERS (and Panelboards) are ONLY listed to use their OWN breakers. There is ZERO incentive for a panel mfr to list their panels with a competitor's breakers in it, so they do not go to that expense. What that means then is that when JQP plugs in a GE breaker into his Homeline load center, he is violating the UL listing of the load center.

But he is the homeowner, right? So what he does AFTER it is inspected and approved is his own business, and more importantly his own risk. If that breaker causes a fire and the insurance inspector determines it was the result of a a breaker used in a manor that violated the UL listing of the load center, then he may (although not likely) deny damages. If it was a "handyman" type of non-bonded and insured 3rd party, he too might be liable, but you run into the old "blood from a turnip" scenario.

So here is the conflict. YOU, assuming you are a licensed and bonded contractor, are at risk if you do it. YOU are supposed to know better and not violate listings of equipment. In that same fire scenario if the insurance inspector determines that YOU installed a breaker in a non-listed manner, the insurance company will come after YOU and your insurance company. So to protect yourself, you should NEVER use a breaker from one mfr in a panel of another unless the PANEL is specifically listed to allow that, and none of them do.

 

[K8MHZ]

I went to a service call a few years back. The complaint was the electric stove wouldn't work all the time. I went to the panel and it was a mix of several different brands of breakers and few were the same as the panel. I pulled the cover off and went to turn off the stove breaker. It was burnt in half and came apart in my hand with half of it stuck on the bus and arcing. I had to shut the main off and surgically remove the rest of the breaker from the bus. I still have the charred remains the breaker somewhere. It's great show and tell when people ask me about using breakers not listed for a panel.