I bought a HEPD80 surge protector to install in an old 100A Pushmatic panel. It has 12 AWG leads and for installation as a Type 2 SPD the paper that came with it calls for a 20A 2-pole breaker; I also seen online places where is says a 30A 2-pole breaker. The instructions also say that it can be installed as a Type 1 SPD ahead of the main breaker, with no overcurrent protection at all.

Additionally, I found this Eaton document which mentions putting their device with 14 AWG wires on a 50A breaker and states "Can a 14 AWG wire be installed using a 50 ampere circuit breaker? Yes. The connecting wires do not carry load current. Instead, they carry only short-duration currents that are associated with a transient event."

So my question is, since it is safe to install it ahead of the main breaker, is it not equally safe to install it on a larger breaker? I'd rather not try my luck installing it as Type 1 on live service wires; and I have a spare 40A 2-pole breaker laying around, but not a 20A (and the breakers aren't exactly cheap)...

  • 1
    If you read the section right below, you must install as listed in the instructions. If the instructions do not mention using a 40 amp breaker, but only a 20 amp breaker, you must use a 20 amp breaker. Only if they give a range of sizes, can you choose.
    – crip659
    Feb 23, 2023 at 17:09

2 Answers 2


Yes, that's fine. If it is approved for a Type 1 insulation that means you could put it on a 10,000 amp breaker if you wanted to.

Actually, Pushmatic terminals are UL-listed for 2 wires per breaker terminal. So you can simply piggyback it onto a breakers being used for other appliances that's what I did with mine. There's nothing wrong with doing this. Mine shares a 30A actually.

It is extremely difficult to find replacement Pushmatic breakers. The new stock made by Chinatticut Electric are complete garbage - rather than license-build the original Pushmatic design, they made an inferior copy that doesn't trip.

  • Thank you, that was my thinking but wanted brighter minds to confirm. Didn't know the Pushmatics were listed for double-tapping, that solves my dilemma. We had an electrician tell us no and Google's top results also say no. Pretty disappointing to hear that that new stock brand is crap, after I already put a subpanel on one of their 60A breakers; guess that gives me an excuse to replace the main panel and upgrade the service...
    – User41943
    Feb 24, 2023 at 14:14

The Installation Manual specifically says to use a 15, 20 or 30 amp 2-pole circuit breaker. Do not use a breaker larger than 30 amp.

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