It's all too easy to blame the RCD if it is tripped by turning on VFD
David Jupp | 25/02/2017 10:21:46 |
978 forum posts 26 photos | I've noticed several threads recently where turning on VFD units has tripped the supply RCD. I too have had similar problems since first installing a VFD some years ago, recently this has seemed to become more of a problem. I've just realised that since I replaced on old floodlamp fitting on the outside of the garage a few weeks ago, the problem has vanished. Now even my largest VFD doesn't trip the RCD when turned on. I don't know if the issue was that the floodlamp was an open face type, or that the weather had got into the PIR motion detector housing. Anyway - the learning (as I recall some have commented in other threads) is don't rush to blame either the VFD or the RCD, carefully check anything else fed from the same supply before buying a replacement RCD with different characteristic. In my case simply isolating the exterior lights at the MCB would likely have pointed to the cause a long time ago. |
John Haine | 25/02/2017 10:51:40 |
5563 forum posts 322 photos | My brother had a similar problem when he had solar panels fitted. Occasionally the main RCD tripped, in the end it turned out to be a spider's nest in a light fitting in an outbuilding. Once you have something a bit leaky, it biases the RCD so a bit extra, such as from an inverter filter, can trip it. |
Martin 100 | 25/02/2017 11:10:43 |
287 forum posts 6 photos | Posted by David Jupp on 25/02/2017 10:21:46:
In my case simply isolating the exterior lights at the MCB would likely have pointed to the cause a long time ago. Not neccessarily as the MCB in most cases is single pole and would only isolate the live, leaving the possibility of a neutral to earth leakage path which the RCD considers exactly the same as a live to earth leakage. |
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