Space allocation for PV equipment

[MyCleveland]

Hope to have an EC add a sub-panel later in the year for a kitchen remodel.

When placing the panel, I would like to leave some backboard space for future PV related equipment.

Questions:
Can the final interface with power system be at a sub-panel or does it need to connect at main panel ?

If I can connect to Sub, how much wall space should I dedicate for this equipment ?
I would guess the system to be 3-5000w...unknown at this time.

Quantity and size of conduits needed up to attic ? While EC is doing kitchen, with some walls open, I will have him run empty conduits 2/3 of way, but short of attic.

 

[ggunn]

Hope to have an EC add a sub-panel later in the year for a kitchen remodel.

When placing the panel, I would like to leave some backboard space for future PV related equipment.

Questions:
Can the final interface with power system be at a sub-panel or does it need to connect at main panel ?

If I can connect to Sub, how much wall space should I dedicate for this equipment ?
I would guess the system to be 3-5000w...unknown at this time.

Quantity and size of conduits needed up to attic ? While EC is doing kitchen, with some walls open, I will have him run empty conduits 2/3 of way, but short of attic.

The only question I can answer is the first: Yes, you can interconnect in a sub panel but with some caveats. You have to be in compliance with 705.12(D)(2)(3) a, b, c, or d in every panel that power could flow through from the inverter(s) to the service.

Answers to all the other questions depend on the size and type of the PV system you get. 3000W to 5000W doesn't narrow it down very much. BTW, most (all?) AHJ's are going to want a dedicated PV AC disconnect on the outside of the building.

 

[jaggedben]

...
If I can connect to Sub, how much wall space should I dedicate for this equipment ?
I would guess the system to be 3-5000w...unknown at this time.

4ft by 4ft square should be enough. You won't really need all that but some flexibility is generally required. It has to meet clearance requirements in 110.26.

Quantity and size of conduits needed up to attic ? While EC is doing kitchen, with some walls open, I will have him run empty conduits 2/3 of way, but short of attic.

A single 3/4" conduit will be sufficient, assuming that you either will have one array, or you can branch out within the attic to reach all roof planes, or you are willing to have conduit run across the roof to reach arrays not above that attic.

 

[GoldDigger]

Just keep in mind that you are not allowed to run the DC and AC sides in the same raceway.

Sent from my XT1585 using Tapatalk

 

[Carultch]

4ft by 4ft square should be enough. You won't really need all that but some flexibility is generally required. It has to meet clearance requirements in 110.26.

A single 3/4" conduit will be sufficient, assuming that you either will have one array, or you can branch out within the attic to reach all roof planes, or you are willing to have conduit run across the roof to reach arrays not above that attic.

I also concur with a 4x4 wall space. That's enough for two inverters and a small load center to combine them.

A single 3/4" is a very small system. Most residential systems I've spec'd, use a 1" conduit for the array power.

There also is the possibility that the solar contractor might put in an irradiance sensor, which would use a 3/4" data conduit.

 

[ggunn]

I also concur with a 4x4 wall space. That's enough for two inverters and a small load center to combine them.

A single 3/4" is a very small system. Most residential systems I've spec'd, use a 1" conduit for the array power.

There also is the possibility that the solar contractor might put in an irradiance sensor, which would use a 3/4" data conduit.

OK, but what if he were to use microinverters? All he would need would be space for the combiner.

 

[jaggedben]

A single 3/4" is a very small system. Most residential systems I've spec'd, use a 1" conduit for the array power.

Hard for me to imagine running 1" conduit every day on residential rooftops. 3/4" is plenty for 3-5kw. It's 4 circuits, which is twice as much as any 5kw would need these days. Of course, we use optimizers or micros on almost every system. I guess if you need a rapid shutdown control cable that could affect things.