Hi all, I have a stage light That is tripping the RCD on my consumer unit.

I've checked a few other things, nothing untoward found so far.

I have a suspicion it might be the ballast, but I have no idea how to test it - any suggestions appreciated.

P.S. there is no lamp in the unit yet ....

 

What is an RDC ?
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I said RCD, Residual Current Detector ...

 

The Lighting Fixture is not designed to be Powered with no Bulbs installed.
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The Lighting Fixture is not designed to be Powered with no Bulbs installed.
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That would not be a pleasant experience during a performance if a bulb blows in one fixture - everything, including the sound, would go off.

I have serviced another of these stage lights, and had it on extended "Test Mode" for many hours - with NO bulb installed, and with no tripping of the RCD.

 

I am starting with the assumption that your ballast and lamp socket are mounted to a metal enclosure- let me know is this is incorrect.

I would remove the easiest of the socket and the ballast from the luminaire first. If that doesn’t solve the problem remove the next part ( the switch). If you remove all of the electrical parts and still have the problem,remove the linecord.

With any luck that will get you there.

 

I am starting with the assumption that your ballast and lamp socket are mounted to a metal enclosure- let me know is this is incorrect.

I would remove the easiest of the socket and the ballast from the luminaire first. If that doesn’t solve the problem remove the next part ( the switch). If you remove all of the electrical parts and still have the problem,remove the linecord.

With any luck that will get you there.

The problem is definitely inside the fixture. I disconnected the load side of the mains input EMI/RFI filter, and it didn't trip the RCD, so the filter, line cord, and power switch are ok.

One thing I've not looked at yet is the IGN module for the ballast, but that's buried deep inside the fixture, and a lot of dismantling is needed to even see it properly, let alone test anything.

Looks like I'm gonna be on this for several hours yet ....

 

Let us know what you find...

 

Let us know what you find...

After taking most of it apart, looking for tell-tale evidence of anything wrong, I've put it all back together, and it's working fine - no tripping.

The only thing I've sorted is the poor earth bonding - painted screw, star washer, ring terminal, into a painted metal plate, no guarantee of a good solid earth connection at all. I've used a dremel to expose the metal plate around the screw holes.

 

To trip the RCD it must have had spurious earth leakage somewhere. I can't see that being a poor earth connection. Perhaps a termination where an exposed piece of wire, or a strand of a wire, brushing a piece of the frame.

It seems that you have tidied up whatever was causing the problem.

 

To trip the RCD it must have had spurious earth leakage somewhere. I can't see that being a poor earth connection. Perhaps a termination where an exposed piece of wire, or a strand of a wire, brushing a piece of the frame.

It seems that you have tidied up whatever was causing the problem.

I didn't find anything untoward, no exposed wire ends, no "trapped" wires, everything appeared to be in good order. I've replaced all the cable ties I had cut off to dismantle it.

I'm slightly baffled.

The modifications to the earthing were for safety, not functionality.

Gonna put all the casings back on, put a new lamp in it, and run it on an extended test.

 

Good work, however it worked! The main think is that the problem is solved, at least for now.

For an RCD breaker to trip there needs to be leakage, usually from the Line but also possibly from Neutral to earth.

Correcting the ground connection is is good for safety and maybe sporatic leakage from something to ground was the reason for the tripping.

 

Good work, however it worked! The main think is that the problem is solved, at least for now.

For an RCD breaker to trip there needs to be leakage, usually from the Line but also possibly from Neutral to earth.

Correcting the ground connection is is good for safety and maybe sporatic leakage from something to ground was the reason for the tripping.

Well it's behaving itself now on test.I switch it off from time to time, let the lamp cool, and turn it back on - still no tripping.

Keeping fingers crossed it's solved

 

Quite frankly, I don't know how these lights passed any sort of safety certification. The containing covers (powder-coated steel) fixed in place with black-painted screws, with absolutely NO metal to metal contact, and no bonding cables on the covers.

I have dremel'd the inner surfaces of the covers, and the chassis where the screws go to provide a metal-to-metal contact. and the screws that are hidden on the bottom of the unit I have removed the paint from the flanges, dremel'd to bare metal around the screw holes, and re-fitted the screws with serrated washers. Don't think I can do any more....

 

If it's tripping the RCD then there's an Earth leakage, i would measure the resistance between the Live and Earth and the Neutral and Earth on the light fitting, With the power disconnected of course.