tripping MCB

[ballyclover]

hi

hope someone can advise

i have a 6amp mcb feeding the combie boiler. the cable comes from the board into a fused switch then into a 4 way junction box, with the cable split to the boiler and timer.

i took one of the spare ways from the junction box and ran a cable to another fused switch from this i took a cable to an outside PIR. All worked well not a problem

Yesterday i added another PIR connected with a cable from the first. This also worked well without problem. However for some reason the MCB will trip. I thought this was an overload problem however it will trip with no load, lights off and boiler on, but not running

its something to do with the 2nd light i am sure, but have no idea what,Both light are in excellent condition with no sign of problems. They were both previously use on my garage and all i have done is move them and connect to a different supply

Anyone any ideas why this might be happening?

 

[ballyclover]

just to add, yesterday it would trip out between 10 mins and an hour after turning off the lights, over night it never went off at all.

just wondering could it be something as the lights cool? or delayed trip

 

[chivers67]

Disconnect the second light and have a look at all the connections, leave it disconnected to make sure it doesn't happen in the first instance.

 

[ballyclover]

disconnected 2nd light and so far hasnt tripped.

worked out the power consumption,2x500w light, 160 watt boiler consumption

works out at 4.8 amps i believe, there is a timer switch also but doubt it takes it past 5, so i pretty sure its not overload

 

[Taylortwocities]

2 x 500 watt lights

Are you trying to light up the Olympic stadium or something?

No wonder the polar ice cap is melting.

 

[ballyclover]

to be honest i didnt know they were 500 watt lights, till i looked at the backs.

gonna but 2 150w lights and hopefully that will solve the problem.

i am convinced its overload, as i have now run each light individually and were fine, connected both up and trip 30 mins later

save the planet

cheers

 

[EFLImpudence]

i have a 6amp mcb feeding the combie boiler. the cable comes from the board into a fused switch then into a 4 way junction box, with the cable split to the boiler and timer.

I would think there should be a 3A fuse in the SFCU.

As you have discovered it is not a good idea to have your lights connected as you have.