60 kW commercial tie in

[Zee]

Been 15 years since I built commercial.

Best way to tie in?

1phase 240 VAC service

58 kW-STC system

3 @ FRONIUS PRIMO 15.0-1 240 INV's (maybe 4)
15 kW each
240 VAC
AC output: 62.5 A each.... 80A OCPD each

(E) equipment: 400A MSP with 2p400 main brkr feeding .......
(dual paralleled 250 kcMil feeder conductors per leg, copper)
......2p 400A breaker in 400A rated SP.

 

[jaggedben]

That's already set up for a load side tap, since there's a main breaker in the panel on the right. Be sure to tap both parallel conductors.

 

[Zee]

Thank you.
Right! So the fact that there is 400A OCPD downstream does mean I can tie in up to 400A of PV as load side tap?

 

[Zee]

Would supply side connection make sense?
Specifically, wondering if a (N) PV breaker can be placed parallel to main breaker in EATON service panel (MSP not SP).
Sorta like a "split service" (2 main brkrs).

I see plenty of physical room.
I do not see bussing options though.

This would be interesting if it is an option per mfctr.

 

[Zee]

That's already set up for a load side tap, since there's a main breaker in the panel on the right. Be sure to tap both parallel conductors.

Thanks again.
If load side tap, would the (N) fused ACD ( I assume) be rated for PV Amps (3x80A=240A), or service Amps of 400A, or other?

 

[Designer101]

Thanks again.
If load side tap, would the (N) fused ACD ( I assume) be rated for PV Amps (3x80A=240A), or service Amps of 400A, or other?

is 240a Ac disconnect easily available though??
All I see is 30,60,100,200,300,400 and son on.. if you install 400A disconnect standard fuse will be 250A.

 

[Designer101]

Thank you.
Right! So the fact that there is 400A OCPD downstream does mean I can tie in up to 400A of PV as load side tap?

i think you can go up to 320 AMPS Continuous inverter output current. That needs 400A disconnect.

 

[jaggedben]

The load side tap is going to be a lot easier than supply side.

You disco needs to comply with 240.21(B). It will probably be rated 300 or 400A, whatever you can get, with your fuses at 250A like designer 101 said.

 

[Zee]

Yes, a load side tap will definitely be easier than a supply side tap.
Great point, and saves me trouble!
However, I was hoping I could get a supply side breaker in there. Oh well.

 

[Zee]

is 240a Ac disconnect easily available though??
All I see is 30,60,100,200,300,400 and son on.. if you install 400A disconnect standard fuse will be 250A.

Silly me, who makes a 240A rated enclosure!

Would my tap conductors need to be sized for the 300A or 400A rating of the ACD I install?
(Despite having 250A fuses.)

Thank you.

 

[electrofelon]

Would supply side connection make sense?
Specifically, wondering if a (N) PV breaker can be placed parallel to main breaker in EATON service panel (MSP not SP).
Sorta like a "split service" (2 main brkrs).

I see plenty of physical room.
I do not see bussing options though.

This would be interesting if it is an option per mfctr.

I was curious about that too. I think that would be a question for eaton.

Yes, a load side tap will definitely be easier than a supply side tap.
Great point, and saves me trouble!
However, I was hoping I could get a supply side breaker in there. Oh well.

that's a rather funky enclosure, I think you would have to talk to Eaton to see if they have the parts available to mount more than one breaker. You might be able to remove that existing breaker bolt on some lugs and come off to a new service enclosure....... I did just that on a switchboard section where I wanted to keep the c-t metering but ditch the service disconnect and go to a new service enclosure. I got the blessing from the inspector first that he was okay with it.

 

[Zee]

Aha a new service enclosure. Could work.
If new service that would involve AHJ and utility....sounds like trouble.

I like the breaker idea.....may call Eaton.

 

[Zee]

Different topic:
Inverter shows 1000 VDC rating. Is that standard V for US commercial PV systems nowadays?
Non habitable building.
Mods are also 1000 VDC rated so would save a lot (60%) on wire and CB's and conduit ....and labor.

 

[electrofelon]

Different topic:
Inverter shows 1000 VDC rating. Is that standard V for US commercial PV systems nowadays?
Non habitable building.
Mods are also 1000 VDC rated so would save a lot (60%) on wire and CB's and conduit ....and labor.

The fronius primo line have always been 1kv string capable. I have used them for resi projects on accessory structures several times and it can be handy. I have talked about this before, but some of their literature does NOT say they are 1KV capable. I recall an explanation by fronius where they essentially said "no one cares about 1kv for resi so we just say 600V even though they do 1kv".

 

[Zee]

Funny Fronius.

I saw that thread and your post. Interesting stuff.

I mean the whole system , if commercial, is typically designed for 1000 VDC nowadays?

Thanks. Around here we have a bit of 1phase commercial power, so Fronius INV's work great.

 

[electrofelon]

Funny Fronius.

I saw that thread and your post. Interesting stuff.

I mean the whole system , if commercial, is typically designed for 1000 VDC nowadays?

Thanks. Around here we have a bit of 1phase commercial power, so Fronius INV's work great.

Yeah pretty much all the commercial systems use 1000 volt strings and 480 3 phase inverters. I've been out of large commercial PV for 4 years now, but at that time 1500 volt strings were just starting to come in as well. As far as I know, fronius is still the only single phase inverter that will do one KV.

 

[Carultch]

Different topic:
Inverter shows 1000 VDC rating. Is that standard V for US commercial PV systems nowadays?
Non habitable building.
Mods are also 1000 VDC rated so would save a lot (60%) on wire and CB's and conduit ....and labor.

Yes, there is a multitude of reasons why a higher voltage has an advantage for transmission and processing of power. It's more economical to build an inverter for higher voltages as well. 1000V PV systems are allowed in commercial applications, whether building or non-building. It is residences where you are still limited to 600V strings, which is why single phase inverters still commonly require 600V and less DC circuits. 1500V is still limited to non-buildings (like groundmounts, and carports).

The thing that you have to anticipate, is that all products between the modules and inverters have to carry a 1000V rating as well. So that would be all connectors, wire, fuses, combiners, module-level power electronics, etc. It also means you cannot mix with <=600V circuits in the same wiring structure without a partition, or without also using 1000V wire for it. It is now common for PV-specific products to be built for 1000V, but much less common for electrical-general products to be built for it. Older PV modules and equipment may not carry a 1000V rating, and may not be capable of being used in a 1000Vdc system.

 

[jaggedben]

You have a 240V single phase inverter that uses 1000V strings? Also isn't rapid shutdown required here?

 

[electrofelon]

You have a 240V single phase inverter that uses 1000V strings? Also isn't rapid shutdown required here?

Fronius. The only single phase inverter that does 1 KV (as far as I know).

 

[Designer101]

Silly me, who makes a 240A rated enclosure!

Would my tap conductors need to be sized for the 300A or 400A rating of the ACD I install?
(Despite having 250A fuses.)

Thank you.

As per my knowledge, it It should be 1.25 percent of total number of inverter output current, here looks like if you install 250A fuses then size per that fuse. make sure you mention the fuses rating at SLD.