Extending a solar panel circuit to accept a load

[chudson]

Hey guys, I have a client who currently has a 1.2kW tracking array. He is in the process of building a new outbuilding and has asked if he can extend off the circuit the supplies the array. Personally I don't see an issue with it as we have space to install a small isolator on the mains side next to the existing isolator and the whole circuit is supplied on a 6mm 3 core SWA with a 20A MCB protecting it. Ive asked what he wants in the outbuilding and he has said 1 58W single fluorescent and a double socket for a battery charger (of course we all know that at some point someone will use this for more). The only issue I could see is the solar array circuits should be, well solar array circuits and nothing more. But I think this would be acceptable deviation from the regs. What do you all think?

 

[TedM]

Not an acceptable deviation from the regs.

 

[Earthstore]

A PV system should be on it's own dedicated circuit, you could open yourself up to tripping issues, also it depends where the generation meter is, why use the generated power befere it gets metered?

Not sure on the regs, if I remember right though, it is not allowed.

 

[chudson]

A PV system should be on it's own dedicated circuit, you could open yourself up to tripping issues, also it depends where the generation meter is, why use the generated power befere it gets metered?

Not sure on the regs, if I remember right though, it is not allowed.

I'd rather not have to do it anyway, would be better if we run the outbuilding all the way back. Thanks guys

 

[TedM]

For reference this is from the MCS PV Guide:

2.3.1 a.c. Cabling
The PV system inverter(s) should be installed on a dedicated final circuit to the requirements of BS 7671 in which:
• No current-using equipment is connected, and
• No provision is made for the connection of current-using equipment, and
• No socket-outlets are permitted.

I don't think there is anything wrong with putting a small consumer unit in the outbuilding (3-way at least) and then splitting the circuits from that.

Ask yourself: How would it have been wired up if the outbuilding was already there when the PV was installed?

 

[BruceB]

It is only the final circuit that has to be dedicated to the PV, not the distribution circuit. So provided the distribution circuit is sized adequately, and by the sound of the additional load it is, then no problem with an additional DB/CU at the end of it.

 

[Gavin A]

as above, we've done that many times with existing garage / outbuilding circuits. Only the final circuit has to be dedicated, so just install a little garage unit to split the circuits off.

Main issue is where the meter is located, as this will have to be on the dedicated circuit