Federal Panel: test the circuit breakers?

In today’s inspection there was a Federal service panel with Stab-Lok circuit breakers. I have a standard comment about such panels, but my question is this: are there likely to be very many – or even any – electricians in a major metropolitan area, such as mine (Detroit) who have the test equipment to confirm whether or not the circuit breakers trip properly under the load at which they’re supposed to?

Similarly, are there replacement circuit breakers available for such panels that are confirmed good?

Circuit breakers are tested on a per unit basis, and not just as straight labor time. Molded case circuit breakers are almost never tested, as the costs involved with circuit breaker testing exceed the value of most molded case circuit breakers. Yes, it is very likely that many contractors in your area will have the expertise and the equipment to test these. It is very unlikely, however, that you’ll have many customers that are willing to pay the price to have it done, as it would be cheaper to replace the equipment.

Thanks, Marc. I wondered how that would work out, since the circuit breakers would have to be disconnected and re-connected in both cases, but there would none of the other installation (the panel itself, wire clamps, etc.) involved. Whenever I’ve installed service panels I found connecting the wires to the breakers the easiest part of the job. I know I’d charge a lot less to disconnect, test, and reconnect circuit breakers than to replace an entire panel, unless the wiring in the panel was a real mess.

Then, you’d be ripping yourself off. I know of no-one that tests and certifies molded case breakers, but if such a service existed, it would be at least 100 bucks a breaker. Twenty breakers, that’s 2 grand. That same 2 grand could have bought you a panel swap.

Then I take it the testing process is a lot more involved than connecting the circuit breaker terminals to wires in a controlled circuit and running a specified load through to see if the breaker trips …

No, but I’m telling you what it costs to do so. You’re starting to sound like a price-shopping homeowner or REA. Stop scaring me.


I suppose you could test the breakers with 2 hair dryers (that will give you a 24a-26a load) but you certainly gotta believe in the circuit conductors.

I would never intentionally test a circuit breaker in a panel. You don’t know what is on that circuit or if you would blow up a subpanel or main panel.

The only thing I would test in a panel would be a GFCI built in to a circuit breaker. Then, I would only test it when I was absolutely sure that there was nothing on that circuit that wasn’t critical (medical, business fax, etc.).