Not connecting inverter directly to consumer unit?

[dougalthedog]

According to the DTI's "Photovoltaics in Buildings" document:

"An inverter supplied from a PV array must preferably be installed in a
dedicated circuit 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."

The use of must and preferably next to each other is surely a bit confusing!

I have recently heard of an installer advising a customer that they could connect the inverter to an existing circuit in say a bedroom if it was going to be too difficult to route the cable to the consumer unit.

I am interested to find out if this practice is widespread and additionally whether any such installation has been part of an MCS annual review.

My gut feeling is that whilst this may save cosmetic damage for the customer, this probably does not outweigh the potential safety concerns or the fact that access would be required for meter reading.

Thanks in advance.

 

[lamb]

According to BS7671, parallel generation plant may be connected to a distribution circuit downstream of the circuit protective device(s), where the current carrying capacity of the cable (sub-main) exceeds the rating of the sum of the generator output and protective device.
In other words, the sub-main cable must be rated to take the full load current and full generation current simultaneously, and assumes the two loads as additive.
However, connecting generating plant directly into a final circuit supplying current using equipment is not permitted by the DTI guide.