Could low voltage trip RCD?

I am a UK resident with an overactive RCD between my electricity meter and my consumer box.

After a recent break in the electricity supply to the entire street, my RCD's started buzzing and at certain times of the day won't let me connect anything that draws any significant amount of power (fridge, cooker, kettle, etc) without tripping the supply.

Even when the RCD is in the 'off' position and all the fuses are removed from the consumer unit, the RCD continues to buzz and refuses to re-set. Surely this isn't right?

This problem is at its worst around breakfast time and in the early evening.

This morning the RCD tripped the power at the same time as the next door neighbour switched on her vacuum cleaner. This happened twice in succession. I doubt the neighbours are to blame, but I wonder - Might I have a faulty RCD? or Could this be caused by a low voltage supply? or Is the RCD just doing it's job?

I'm working on a tight budget so I'd really rather not have to call in a qualified electrician to replace the RCD if the RCD's not really faulty! So far my electricity supplier's rather unhelpfully said that the problem's up to me to fix because the RCD's downstream of my meter.

I thought I'd draw a few diagrams to see if it helps understand what I'm dealing with:

1) The basics:
formatting link
Consumer unit, simplified wiring diagram:
formatting link
Consumer unit, wiring diagram as it actually appears:
formatting link
Thanks!
Reply to
matt.busfield
Loading thread data ...

No it's not.

Ah -- it looks like you have a voltage operated earth leakage circuit breaker, not an RCD, i.e. two separate earth terminals, and the '?' going to an earth rod?

The problem could be caused by someone else's earth leakage leaking back into your system through your earth rod. This would also explain why it carries on buzzing when it's tripped off. The fix for this from your point of view is to have it changed to an RCD.

However, this is probably also showing up a fault in the supply network and/or a neighbour's wiring. You should probably notify your supply company -- it might be a broken PEN conductor somewhere in a TN-C-S network which is quite a serious fault.

Reply to
Andrew Gabriel

Thanks for taking the time to reply Andrew.

You're right I think, that the '?' in my diagram

formatting link
probably an earth connection. (I've had to label it '?' because the cable goes out of sight, passing behind the board on which the consumer unit is mounted).

I shall try again to contact my supplier in light of your very helpful comments. This time I'll try faxing my request for assistance in the hope that I will bypass the call managers and get through to someone who knows their stuff.

Reply to
matt.busfield

Early evening and morning? are you close to a street light by chance? Ask your supplier to monitor the incomer ( it's free) Street lights are known to interfere with RCDs although usually by tripping them. If, as has been suggested, it is in fact a VFD then again you need to have the supply monitored to ensure there is nothing out of limits.

Reply to
Jb

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.