By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

RCD problem that wasn't

It's all too easy to blame the RCD if it is tripped by turning on VFD

All Topics | Latest Posts

Search for:  in Thread Title in  
David Jupp25/02/2017 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 Haine25/02/2017 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 10025/02/2017 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.

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate