Replacing a breaker in main panel in a house which also has solar

[cppoly]

A panel inside a house has a 100A MCB and also has a PV system which also feeds the panel.

There is a sticker on the panel that says to shut off the solar disconnect prior to working in the panel but if I shut off the 100A MCB, wouldn't this prevent any electricity from getting through this point (as in the case of having to replace a 20A breaker)?

Do I need to notify the solar company if I have to shut off their disconnect? I don't want to accidentally cause any damage to the solar equipment by shutting it down without them knowing about it.

 

[jaggedben]

For most solar systems without battery backup the solar output will deergenize when disconnected. Follow the same standard procedure you always should in any panel. Turn off the panel, measure voltage where you intend to work, proceed to work only if voltage is gone. If there's still voltage call the solar company and/or look for other sources such as a battery inverter.

I hate those boy-who-cried-wolf stickers. Especially now with increasing exceptions where battery backup keeps things energized.

You will not damage the solar system by opening the disconnect. If it can't take that, like any other equipment, it's not your fault.

The most likely pitfall for you here is forgetting to turn the solar back on, thus causing the homeowner to lose money, which they may not notice for a while while the amount builds up.

 

[cppoly]

Thanks

 

[Fred B]

Is what you have load side backfeed or supply side tap connection. If supply side tap the solar will stay energized even if you turn off main breaker.