DIY Doctor

Buzzing RCD Consumer unit/supply box

Postby iris » Fri Dec 14, 2007 1:36 pm

I have noticed quite recently that when I go to my garage where my RCD unit and electricity supply box is, I can hear a buzzing noise coming from one or other of these boxes. What does this mean? The noise comes and goes. Is it dangerous?
Rank: Labourer
Progress to next rank:
Posts: 1
Joined: Fri Dec 14, 2007 1:24 pm


Simply Build It

Postby sbelectrical » Fri Dec 14, 2007 8:29 pm

hi there this is not a normal thing for an rcd to be buzzing i would suggest you get an electrician to look at it sooner rather than later as it could be
loose conections and the buzzing sound is arking of the cables which could result in fire, most electricians should come out to asses the job for free so ring one soon as mate.
Rank: Apprentice
Progress to next rank:
Posts: 12
Joined: Fri Dec 14, 2007 8:22 pm

Postby djsamm » Sun Apr 26, 2015 1:55 pm

if you have a high inductive load for example HID, fluorescent lighting or triac dimmers that can cause the RCD to buzz. also if it has a high load on one of the MCB's they can sometimes buzz however this depends on the breaker's condition. some theater lighting dimmers and electric motors cause RCD's to buzz.
Rank: Labourer
Progress to next rank:
Posts: 2
Joined: Sun Apr 26, 2015 1:49 pm

Postby ericmark » Mon Apr 27, 2015 9:48 am

The older RCD's had larger current transformers than the new ones and no electronics these may buzz in the main it means you have some earth leakage but not enough to trip it.

The problem with RCD's is the strain the wires put on them can stop them working they are detecting very small amounts of current. So after one is fitted one uses a special meter to check both trip currents and times. 40 mS is too short of a time for a stop watch it needs special meters to measure it.

So changing a RCD is something you need an electrician for as the meters are just too expensive to be worth doing DIY.

So yes it's an electricians job no real way around it.
Rank: Project Manager
Posts: 2503
Joined: Fri Oct 02, 2009 8:49 pm
Location: Llanfair Caereinion, Mid Wales.

Display posts from previous
Sort by
Order by

  • DIY How to Project Guides
  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!

  • Related Topics