Interconnection for a large industrial system

[solarken]

I am preplanning for quoting a rather large PV system at a municipal facility. They will have two 4000A services from different substations. I was provided the single line, screenshot attached, which does not look right to me. It shows two 4000A services feeding a 4000A switchboard through two 4000A breakers, with an electrical/mechanical interlock and symbols that suggest that both services would be connected simultaneously or disconnected simultaneously. I am thinking one of the breakers need to be open and one closed, so that only one can be on at a time via the interlock. Am I missing something?
Also, the service is brought in at 480V with 12 parallel sets of 400MCM, for each service. Trying to get my head around how to interconnect a PV system to this with the two services and the 12 sets of conductors in each. Anyone come across anything similar that has some suggestions?

 

[don_resqcapt19]

I expect that is interlocked so only one can be in the on position at a time.

 

[ggunn]

I have seen this sort of things a few times. The interlock note doesn't specify whether only one or the other is on, or both are on and off together, and there is no bus rating shown. I have seen them configured both ways.

 

[pv_n00b]

If they want the PV to back feed whichever service is connected then you will have to connect to the SWBD, either thorough a CB or a bus tap.
The way they show the interlocked CBs is incorrect but typical. Most of the drafters only use the closed CB symbol and can't be bothered to go get the open one. For the quote you can assume they are interlocked to only connect one service at a time and put that assumption in your quote. When you do the site walkdown you can verify it.
It would be a pain to try to tap just one of the parallel service feeders since you would have to hit all 36 conductors.

 

[solarken]

If they want the PV to back feed whichever service is connected then you will have to connect to the SWBD, either thorough a CB or a bus tap.
The way they show the interlocked CBs is incorrect but typical. Most of the drafters only use the closed CB symbol and can't be bothered to go get the open one. For the quote you can assume they are interlocked to only connect one service at a time and put that assumption in your quote. When you do the site walkdown you can verify it.
It would be a pain to try to tap just one of the parallel service feeders since you would have to hit all 36 conductors.

I agree, only only one service can be used at a time if the bus rating of the switchgear is correct. If the utility permits connecting at the Czt cabinet, that would be easier, but still, with two services, would likely need to switch between whichever is active with a big transfer switch or equivalent.