RCD Problems with a twist

[Elecon 2004]

Hi,
I am having ongoing problems with Rcd in clients house.
It is worth pointing out that I am living and working in Spain.
The problem is continual nuisance trips when there is a power cut (there are loads when the weather is bad) the rcd is tripping when the power goes of,so it appears that it is the absence of a load that is causing the trip.
The rcd is 30mA as per UK regs and it is a TT system here Ihave read much on various forums but am struggling to resolve the problem.

 

[Darkwood]

Welcome to the forum Elecon 2004

 

[malcolmsanford]

(1) Is it a voltage operated RCD, they often trip in storms
(2) Faulty RCD
(3) Double pole RCD in there could be a milli second or so delay in the disconnection of supply between Line/Neutral and the device will react on the unbalance

 

[Deleted member 26818]

Unless the RCD is a latching type, it will switch off if there is no power.

 

[UKMeterman]

1.
The power cut is often due to lighting this can cause big transients through any EMC filters on appliance, these can appear as earth faults and trip circtain rcds
2. Old RCDs might be out of spec and trip at very low leakage.

So
1. read http://www.select.org.uk/downloads/BEAMA Installation RCD Handbook V2 2010 updated (2).pdf
2. Do the standard tests on the installation including standing leakage.
3. Some of the better RCDs have protection against transient trips, have a chat with ABB
4. Consider some upstream surge protection, again have a chat with ABB.