pv arrays and rcd protection

[kingbob]

A friend had a pv array fitted which fed into a 16a mcb on the non rcd protected side of a split fuse board. The fuse board has now been brought up to date with the fitting of a second rcd so that all circuits are protected. Now unfortunately the rcd covering the side of the board that the array is on trips occasionally, sometimes several times in a short period of time. All the circuits test ok, insulation, e-n etc. Could the pv array be causing this problem

 

[Earthstore]

No, the person who put the pv onto a shared RCD has caused the problem.
unless certain rules apply, then pv should not be on an RCD but never on a shared RCD.
I hope this helps.

 

[sedgy34]

I would imagine if they looked at the cable from the inverter to the db it wouldn't require rcd protection, so wrong choice of distribution board.

 

[jonnyboy1]

Or fit rcbo for solar circuit if choosing this type of db

 

[SolarCity]

Next time the RCD starts tripping out, turn off the breaker that is supplying the PV system. Try switching the RCD back on. If it stays on, leave it for a few minutes and then switch the PV breaker back on - if it trips then it is very likely that it is the PV system that is causing the problem - or at least the main part of the problem.

Regardless, your system needs attention anyway. PV systems should not be installed on a shared RCD - it needs to be on its own seperate breaker. The reason for this is that a PV system could still be producing power after the RCD has operated. Therefore, all of the circuits protected by that RCD could still be energised, at least long enough to mess up your disconnection times.

To be fair to the electrician that changed the board, it is not a generally well known problem - even amongst the PV installers themselves.