200A sub panel off a 200A main.

[rszimm]

I’ve got a 400A main panel. Technically it’s a 200A/200A split main panel. The secondary 200A goes to a sub panel that essentially serves as the main house panel. The actual primary 200A is more or less unused. There’s a 40A solar circuit on it and a 15A GFCI breaker that goes to a shed.

So I’m building a guest house/shop and in a perfect world I’d like to pull wires for a full 200A subpanel at the guest house from the pretty much unused 200A main. So my question is if I need a 200A breaker installed in the main panel, or can I tap directly off the main 200 A breaker? (Sub feed block). It would seem the 200A main breaker protects the wires so a second 200A breaker seems redundant. However, the 40A solar has me concerned. Would I have to size up the wire to handle 240A? Also, I think the largest sub feed block you can get for my Eaton panel is a 225A block, which is less than the full 240A.

 

[Cow]

Can you post some pics of the panel with the covers off?

 

[rszimm]

I’ll try and snap one tomorrow. In general here’s a drawing: https://www.eaton.com/ecm/idcplg?Id...dition=Primary&dDocName=96-5310.DWG.pdf_47851

the secondary breaker is filled with a CSR 200a going to the main house panel. Otherwise everything is empty save for the 15a Shed GFCI and a 40A solar breaker.

 

[Chamuit]

Is your first panel a Sun Valley panel with two pullouts?

 

[rszimm]

It’s an Eaton HP404040SH with two CSR 200A main breakers wired in parallel.

 

[david]

I’ve got a 400A main panel. Technically it’s a 200A/200A split main panel. The secondary 200A goes to a sub panel that essentially serves as the main house panel. The actual primary 200A is more or less unused. There’s a 40A solar circuit on it and a 15A GFCI breaker that goes to a shed.

So I’m building a guest house/shop and in a perfect world I’d like to pull wires for a full 200A subpanel at the guest house from the pretty much unused 200A main. So my question is if I need a 200A breaker installed in the main panel, or can I tap directly off the main 200 A breaker? (Sub feed block). It would seem the 200A main breaker protects the wires so a second 200A breaker seems redundant. However, the 40A solar has me concerned. Would I have to size up the wire to handle 240A? Also, I think the largest sub feed block you can get for my Eaton panel is a 225A block, which is less than the full 240A.

If you install a 200 amp breaker to protect your feeder to the guest house the 125 % of the solar output current would not be an issue on your guest house feeder

in other words the feeder would not be a tap if protected on the supply end (main service panel)

 

[rszimm]

If you install a 200 amp breaker to protect your feeder to the guest house the 125 % of the solar output current would not be an issue on your guest house feeder

in other words the feeder would not be a tap if protected on the supply end (main service panel)

Makes sense except I believe BR breakers only go to 150A.