Lights keep tripping

[Teddy54]

Just been called to be at a job 4oclock (on a friday!) were the d/s lighting circuit keeps tripping. They havn't had an alterations in the last 6 months and there is no spot lights.

Anyone tell me what common occurences could cause this? Also the best method to start with the process of elimination?

Cheers

 

[Ponty Massive]

Is the RCD or MCB tripping?

 

[Teddy54]

Mcb

666

 

[Ponty Massive]

Walk around the house scratching your chin, making the whoooo, tut tut noise, get them to ensure the kettle is working whilst you quickly whip out the d/s lamps from the fitting, make sure there's not transformers or dimmers on the circuit then give the L-N a blast with your megger!!

L/V light with transformer has gone or lamp blown and there's a short between L-N?? That would be my starting point!

 

[truckster]

Testing is the only way to find it. Check how many lights are n the cct to eliminate overload. Seperate the cct at a light point and narrow down where the problem may be.Check outside lights for moisture. As its the d/s lights It could be a pinched cable or even a nail that has nearly penetrated the cable so when someone walks on it. pop!

 

[telectrix]

i would first check to see if the |MCB holds with no load ( all lights switched off, but lamps still fitted) then, if it holds, clamp meter the cable in the CU and get the customer to switch each light on in turn, till either 1. you get a high current reading, or 2. it trips. otherwise, it's down to testing.

 

[Octopus]

I'd be asking whether they have ever had problems with rodents!

I had a customer recently with an intermittent "pop" of the MCB, and could use the light for a while - however in the end the MCB popped everytime the light was switched on -it obviously took the rodent a few weeks to do his worst!

 

[1shortcircuit]

I had a customer recently with an intermittent "pop" of the MCB, and could use the light for a while - however in the end the MCB popped everytime the light was switched on -it obviously took the rodent a few weeks to do his worst!

And I pretty much guarantee you that 99.999999999% of people you ask this question will NOT admit to even suspecting they have rodents sharing their home let alone seeing one

 

[Octopus]

And I pretty much guarantee you that 99.999999999% of people you ask this question will NOT admit to even suspecting they have rodents sharing their home let alone seeing one

Interestingly when I asked about rodents they said yes immediately that there was a history!

 

[1shortcircuit]

Interestingly when I asked about rodents they said yes immediately that there was a history!

0.0000000001% found?

That's good going, your hourly rate must be very persuading in these circumstances lol

:thumbsup