View Full Version : RCD tripping

17-02-2013, 09:16 PM
Keep tripping the rcd in the workshop. I have had a spark check the wires for earth leak and all seems ok. Anyone had problems with a VFD causing this sort of problem? I am reluctant to go to far with replacing wiring as if all works out I will be building a new workshop soon.


Web Goblin
17-02-2013, 09:50 PM
A vfd could be causing the problem but then again so could a pc or anything with power supply in it.
This could also be because the rcd is faulty as well and tripping below its rated current. Did the spark check the rcd with an rcd tester?

17-02-2013, 11:39 PM
Are you switching both neutral and live to the VFD?
If you are, change it so you're only switching the live. I've had this problem in the past, and now whenever wiring up a VFD, I just switch the live.

Some details can be found at HowTo: How to Use Inverter Drives with RDC Earth Leakage Protected Supplies (http://www.inverterdrive.com/HowTo/How-to-Use-Inverter-Drives-with-RDC-Earth-Leakage/)

Web Goblin
18-02-2013, 06:08 AM
Now that Im not on my phone and I can see the site properly,when does the rcd trip? Is it at power up, starting the spindle or after it has been running for a while? Does the rcd trip at any other time? Is this the main rcd on the distribution board or do you have a separate one for the vfd circuit? This could also be an accumulation of leakage from various devices in the workshop and the vfd is just enough to add to it to trip the rcd.

23-02-2013, 08:36 PM
Guys thanks for all the help. Been ill and so not been up to doing much. I did though find the problem. One of the wires to the spindle had broken the joint so was flapping about and presumably touching to earth. Sorted. The workshop/garage is about to be replaced and extended a further 2.2 mtrs and will be a bit higher. Then the electrics will be installed properly without trailing leads connecting everything.