How do I connect a generator to a panel that already has a PV system?

[Coppersmith]

Client has a 13,000 watt portable generator and wants a generator inlet on panel. A PV system is connected but I don't yet know if it's a line side tap or a backfed breaker. I know the PV system has to be disconnected when panel is on genny power. How do I install an interlock that guarantees both utility power and PV system are disconnected when genny is connected?

Edit: probably a line-side tap based on photo I just got.

 

[Coppersmith]

I think I solved my own problem. Please check my work. I'll install a 200 amp manual transfer switch before the existing panel. I'll route utility power into one side of xfer and the add the solar tap to that side. The other side will be genny. Output to existing panel.

 

[jaggedben]

Sounds okay.

 

[Another C10]

How do I install an interlock that guarantees both utility power and PV system are disconnected when genny is connected

Some may criticize my method, Example: Lets say my client has a 50A Generator, I usually purchase a Reliance 50/50 Transfer switch panel with distribution, I then feed the Transfer panel with a utility fed 50A breaker. I determine which circuits could/should be supplied by the 50A utility supply and route them to the transfer switch as well, were they land on their appropriated breakers, then I add the 50A 240v receptacle to accommodate the generator supply. I believe my safeguards are sufficient due to the fact that the branch circuits are isolated from any other power source available other than what's being fed from the utility side 50A supply I provided, eliminating any chance of the generated power flowing onto the main panel bussing.

 

[ggunn]

I think I solved my own problem. Please check my work. I'll install a 200 amp manual transfer switch before the existing panel. I'll route utility power into one side of xfer and the add the solar tap to that side. The other side will be genny. Output to existing panel.

That's the way I'd do it.

 

[ggunn]

Some may criticize my method, Example: Lets say my client has a 50A Generator, I usually purchase a Reliance 50/50 Transfer switch panel with distribution, I then feed the Transfer panel with a utility fed 50A breaker. I determine which circuits could/should be supplied by the 50A utility supply and route them to the transfer switch as well, were they land on their appropriated breakers, then I add the 50A 240v receptacle to accommodate the generator supply. I believe my safeguards are sufficient due to the fact that the branch circuits are isolated from any other power source available other than what's being fed from the utility side 50A supply I provided, eliminating any chance of the generated power flowing onto the main panel bussing.

The main issue is to disallow there to ever be continuity between the PV system AC conductors and the generator.

 

[Coppersmith]

Thanks for the help. Submitted a bid based on above plan. Now I just have to see if I win the bid.

 

[Electricman7]

Client has a 13,000 watt portable generator and wants a generator inlet on panel. A PV system is connected but I don't yet know if it's a line side tap or a backfed breaker. I know the PV system has to be disconnected when panel is on genny power. How do I install an interlock that guarantees both utility power and PV system are disconnected when genny is connected?

Edit: probably a line-side tap based on photo I just got.

These guys make custom Interlock Kits for any scenario: https://interlockkit.com/custom-manual-transfer-switch/

They attach to the existing panel cover! Super easy!
Check out this install video. The kits all work to create mechanical interferences with any breaker to lock it out when needed.

YouTube install video: Interlock Kit Install Video

 

[Ravenvalor]

These guys make custom Interlock Kits for any scenario: https://interlockkit.com/custom-manual-transfer-switch/

They attach to the existing panel cover! Super easy!
Check out this install video. The kits all work to create mechanical interferences with any breaker to lock it out when needed.

YouTube install video: Interlock Kit Install Video

They make great products. I have installed many of their kits. It would be interesting to see what they could come up with in a scenario where the service panel has a PV breaker on the opposite end of the bus as the main disconnect. If anyone can come up with something it would be these guys.

 

[electrofelon]

I know this thread is a little bit old, but I am confused by some of the responses. Op seem to think it was a line side connection. If so there was nothing he needed to do but install an interlock. A 200 amp manual transfer switch seems like a horrible idea completely unnecessary and expensive.

 

[Coppersmith]

I know this thread is a little bit old, but I am confused by some of the responses. Op seem to think it was a line side connection. If so there was nothing he needed to do but install an interlock. A 200 amp manual transfer switch seems like a horrible idea completely unnecessary and expensive.

Yes, you are correct. I just didn't see that an interlock would solve the problem. The client called me to say she had received two other quotes, both of which said they would use interlocks. She asked me if an interlock would work and after a few seconds thought I agreed it was the better solution. I requoted and won the bid.