RCD tripping

[yellowvanman]

Email from customer:

Our Solar PV installation is protected by a 30mA RCD in it's own CU which regularly trips during the morning inverter startup at this time of year (when the roof is persistently very wet). We have a transformerless grid-connected Power One Aurora inverter, and I understand the 30mA RCD is just a little too sensitive.

Been a long time since I've done PV! I've got no other info, so don't know where the invgfertor is sited.

Just checked a Power One manual and no mention of RCD protection needed, so if no cables are concealed he doesn't really need an RCD, if its not TT?

Any recommendations for tansformerless invertors needing RCD protection?

 

[Gavin A]

If it doesn't need RCD protection to protect the cable - ie unless it's buried less than 50mm in a wall, then it doesn't need an RCD / could be put on a 100mA.