AC disconnect and correct wiring for Micro inverter

[doctorman]

It gets very hard for the next guy when you keep switching cable sizes. Someone might see the bigger wire and think they can increase the breaker size, but in reality when done and the other end of the wire it is small it is dangerous. In this situation it could cause a house fire. Upsize the THWN to match the Romex if possible. I am sure the cost is not worth a life. Correct me if I am wrong.

If I switch from #8 THWN to #4 Romex I will be putting it in combiner with breaker of course ,
I dont htink it would pass inspection otherwise,
in that case the romex would not need a breaker, and would connect to main service panel directly

[inetdog]

...
... because NEC prohibits splices within a service panel.

Not true.

[Ampster]

Not true.

Good to know. My electrician told me that but maybe he was referring to local code.

[inetdog]

Good to know. My electrician told me that but maybe he was referring to local code.

Possibly, but I am not aware of any major locality that specifies that. Some inspectors try to enforce such a provision without any code citation to back it up. (Referred to as shirt-pocket rules.)
The situation may be different in Canada, though.

[bcroe]

It gets very hard for the next guy when you keep switching cable sizes. Someone might see the bigger wire and think they can increase the breaker size, but in reality when done and the other end of the wire it is small it is dangerous. In this situation it could cause a house fire. Upsize the THWN to match the Romex if possible. I am sure the cost is not worth a life. Correct me if I am wrong.

That is an interesting point, I wonder if there are any guidelines of labeling, etc for the situation of over
sizing a run to reduce voltage drop? I have been plotting getting back most of the 1000 KWH a year
a 600 foot 240VAC loop costs me in resistive losses. A piece of the loop has already been replaced with
1/0 for the pair of 240VAC wires, while the circuit breaker and hardly used neutral remain for 2 gauge.
I will probably not be the last person to own the equipment.

Now that I own a trencher, the possibility of replacing the longest segment (between buildings, more
circuit breakers along the way) is practical. 1/0 or aluminum 2/0 would do the job of reducing voltage
loss, using a neutral and breaker just sized for the actual currents. Bruce Roe