There are no complete stickers on the panel, just a partial one that ID’s it as a Hart-Murray. This is a service for two homes, one(ours) has a 90 amp, the other has 100amp. How do I ID the capacity of the main?

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    Usually the main breaker has that molded right into the handle. i.e. if you zoom in on the one here, it's a 100A main: diy.stackexchange.com/q/231879/18078 Take off the deadfront and look for more stickers in better shape, unless taking off the dead front is out of your comfort zone. Don't touch anything inside there, there are parts that are ALWAYS hot, even with all breakers turned off. You can also check what "class" your power meter claims to be. Then edit to provide pictures, becasue we certainly can't begin to guess from the words thus far.
    – Ecnerwal
    Commented Jan 22, 2023 at 15:21
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    Can you post photos of the panel in question please, including the partial label and the main breaker? Commented Jan 22, 2023 at 17:33
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    We'd need to see pictures of the equipment. There's a weird trick you can do that can allow solar up to the full capacity of the panel (e.g. 100A solar on a 100A panel). Commented Jan 22, 2023 at 19:56

1 Answer 1


Call your power company and ask them what size of service they think you have.

You can also look at the main breaker (first breaker past the meter).

However, on some older panels, there is not one main breaker, but actually up to six. These older panels are a hot mess, and have been outlawed.

You always have, as a "Hail Mary" play, the option to replace your meter pan with a meter-main. This is not possible to DIY but it will establish a main breaker - which solves any safety problems with "Rule of Six" panels. However, of more interest is that many meter-mains are designed with a "solar tap". Thus the solar is able to bypass the main breaker(s), and as such, there is no limit to the size of the solar system other than your service size.

This solar tap can be improvised with any meter simply by splitting the load side of the meter to serve both your original panel and a new panel. However this new panel can serve only solar systems.

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