705.12(B)(2)(3)

[fandi]

Hello All,
Input: - The residential 120/240V 200A MSP only has a 200A breaker and a meter.
- 200A pnl B has three bus sections as shown connected to each other via the 'Microgrid interconnection device'.

At the first glance, this panel B is complied with 705.12(B)(2)(3) option c) for each bus section:
- Bus sect 1: total breaker = 40A < bus rating of 125A.
- Bus sect 2: total breakers = 40A + 125A = 165A < bus rating of 200A.
- Bus sect 3: total breaker = 20A < bus rating of 125A.

However, with this configuration, one bus can feed/receive power from other buses. So my question is: Can 125A bus section 1 be overloaded if more than 125A power runs from the MSP to feed 40A loads (on bus sect 1) AND 125A loads (on bus sect 2)?
Do we need more literature from the manufacturer to find out how the 'Microgrid interconnection device' works to prevent the above from happening?
Thanks.

 

[fandi]

It seems that the thread gathers no interest. Please let me know if it's in the wrong section. I'll try to repost in another subsection. Thank you.

 

[wwhitney]

You could try the PV section. What is the make and model of this equipment?

Cheers, Wayne

 

[jaggedben]

The diagram makes no sense. A 125A bus in between a 200A breaker upstream and a 200A bus downstream?

If the whole enclosure assembly with the MID and busses is a listed assembly then it doesn't have to follow 705 and other code rules. But if that's the case I'm going to assume that either the instructions are not being followed or the diagram has some inaccuracies. And the code does require the instructions be followed.

If it is something field assembled then you have some problems with more code sections than just 705.12. For example the upper 125A bus doesn't have proper overcurrent protection from the utility side.

I agree with Wayne that knowing the make wwould be helpful.