Ac isolation on pv

[pogson6]

Hi Guys,

Is there a requirement or a guideline that stipulates where the AC lockable isolator goes at the mains?, i.e just before or after the generation meter (im classing the inverter as the supply).

I would have thought just before the gen meter as you can then work on the meter (if needed) by opening the isolator and opening the MCB PV circuit for total piece of mind. I know that killing the AC supply would/should cause the inverter to cut out as g83 requirement but it just feels right to physically operate a device. If you put it after the gen meter then you would also have to operate the isolator at the inverter which might be up in the loft.

When you do your installs where do you position your isolator???

 

[sharpener]

The Electricity Safety Council guidliness http://www.esc.org.uk/fileadmin/user_upload/documents/industry/best_practice/BPG3_11.pdf
show the meter between the isolator and CU (A) as you suggest but the DTI Guidelines 2nd edition show it on the inverter side of the isolator (B).

I guess either is electrically satisfactory but I agree with you for the reasons you give. The rationale for lockable isolators is so you can work somewhere else in safety, this clearly isn't needed where you have the consumer unit/meter/isolator all within your sight.

My installers wanted to do (B) but were happy to do (A) as I had a specific reason for requesting it; otherwise the meter would have been too high from the ground to read easily (which contravenes the rule about not needing tools, a ladder or a torch) and/or the pre-installed 4mm^2 cable from the loft would not have been long enough.

 

[moggy1968]

I've done both depending on space etc. don't really see as it matters that much to be honest!!