Tripping lights

[Wilf1982]

I have a consumer unit in my garage which has a circuit for sockets and a lighting circuit. On the lighting circuit is a flo tube and 3 outdoor lights and a security flood light. The lights are on a 3 gang switch the flo tube being two way with another switch else where. When the outdoor lights are turned on all works fine but sometimes when they are turned off the main mcb will trip instead off the mcb for the specific circuit. It happens mainly with the outdoor lights but sometimes happens with the flo tube as well.
Any suggestions appreciated
Thanks

 

[Spark123]

What is tripping, is it an RCD - has a test button?
Is the 3 gang switch in good condition?

 

[PrenticeBoyofDerry]

Is the main isolator to this unit also an RCD?
If so you have an earth leakage fault, this could be due to moisture in outside fittings or faulty flo fitting!

 

[PrenticeBoyofDerry]

Might be worth disconnecting the fluorescent fitting from circuit and see what happens!

 

[Wilf1982]

If it mainly trips when switching off the outdoor lights would a faulty flo tube be causing this if it wasn't being used?

 

[Spark123]

I was thinking arcing in the switch or something behind, usually something leaky will trip when switching on

 

[PrenticeBoyofDerry]

If it mainly trips when switching off the outdoor lights would a faulty flo tube be causing this if it wasn't being used?

If it mainly trips when switching but not trips all the time, it could be worth investigating the switch and switch terminals. As Spark123 suggests.

Has this been happening for awhile or just started, how's the whether in your area?

There are number of causes for RCDs to trip.
My suggestion of disconnecting the florescent fitting, was because it would be one of the easiest task to do and could eliminate a possible cause quickly.

 

[Wilf1982]

I will try these out tomorrow and post back what I find thanks for the help

 

[securespark]

I have found odd faults where the RCD trips when switching OFF rather than ON.

Still a short somewhere, so need to start isolating some wiring to narrow it dowm.

 

[Wilf1982]

I tried a few things today. First I disconnected the flo tube and tried the lights, it tripped. Then I disconnected the outdoor lights 1 by 1 and tried it, it tripped each time (only when switching off). The only connections are where the three lights connect to the main power in the ip66 box all connections fine. Insulation fine. (cable is one week old). I also tried moving to different switch on the 3 gang switch it tripped when switched off. I can have all the lights on,flo tube, flood light and 3 bulkhead lights with no problem if I switch the flo on/off a few times nothing trips, if I turn the flood light on/off few times nothing happens then if I turn the bulkhead lights off once the 40amp main switch trips so still none the wiser ......

 

[Wilf1982]

I have narrowed it down to the lights. I connected a standard lantern with 60w bulb to connection box at bottom of garden and there was no problems, but when changed back to the new lights it began tripping.(connected each individually). They are 13w g24-2 pin lights Each with transformer inside maybe the setup is wrong? Any advice

 

[PrenticeBoyofDerry]

Could be a faulty transformer!
Can you disconnect this individual also?

 

[Wilf1982]

All the lights are brand new and each have a transformer. I connected them 1 by 1 and each time they tripped the mcb. I don't think they could all be faulty. Is there a way of testing the transformer?

 

[PrenticeBoyofDerry]

Have you wired them the right way, 230/240 to 230/240 in?
If not it will trip the MCB and they may no longer work!
Can you upload pictures?

 

[Wilf1982]

Untitled

• Wilf1982
• 14 Jul 2012
• 1