Location of load side secondary power source output connection on center-fed switchgear

[Jefffall]

Hi all,
I am looking at replacing an old 3000A, 208V, 3 phase switchgear line up that is currently center-fed from underground and of course the electrical room is just big enough so we are not able to move the lineup left or right so we are looking to reuse the existing center connection. The fun starts with us looking to add a PV system with 1431A of output circuit current to the new lineup.

I have two questions:
One is with this being a commercial center-fed connection with a 3000A main breaker is my only option to use 705.12 (3)(1) and size the bus for 5000A because I do not have the opportunity to have the primary and secondary sources on either end?

Secondly if this is the case does it matter where on the bus the PV connection is placed per 705.12(3)(1)?

705.12 (3)(3) does not work because we have way to many OCPD's to reconnect.

 

[ggunn]

Hi all,
I am looking at replacing an old 3000A, 208V, 3 phase switchgear line up that is currently center-fed from underground and of course the electrical room is just big enough so we are not able to move the lineup left or right so we are looking to reuse the existing center connection. The fun starts with us looking to add a PV system with 1431A of output circuit current to the new lineup.

I have two questions:
One is with this being a commercial center-fed connection with a 3000A main breaker is my only option to use 705.12 (3)(1) and size the bus for 5000A because I do not have the opportunity to have the primary and secondary sources on either end?

Secondly if this is the case does it matter where on the bus the PV connection is placed per 705.12(3)(1)?

705.12 (3)(3) does not work because we have way to many OCPD's to reconnect.

Can you build a supply side connected PV system and bypass all that?

 

[Jefffall]

Space outside of the room is at a premium so it would be rough placing a 2000A disconnect.

 

[jaggedben]

I would say this why they put 705.12(3)(5) in the code. Presuming it costs less to hire an engineer than to install a 5000A bus.

 

[jaggedben]

Space outside of the room is at a premium so it would be rough placing a 2000A disconnect.

What does outside the room have to do with it? Granted I don't know anything about designing or ordering switchboards. But can your new switchgear not have one service disconnect for the loads and another for the PV?

 

[jim dungar]

Are you sure the complete lineup bussing is 3000A rated? 50 years ago it was not uncommon to find reduced capacity bussing, especially with center fed lineups.