Fuse box tripping after fitting additional lights

[PG]

My brother had an extension built where the builder fitted 3 light fittings. 2 light fittings are controlled by one switch & the 3rd light is controlled by another switch.

When all 3 lights are switched on the fuse box trips.

The builder claims that there is nothing wrong with his electrics & says that the fuse box can't handle the load.

This is a new modern fusebox installed by a qualified electrician 1 year ago in a 3 bed semi.

I asked the builder if the new wiring is on its own circuit & connected into its own terminal on the fuse box and he says it is. He says he has not added onto an existing circuit.

He has now connected one of the lights to a plug & has plugged it into a socket to supply power to it in the mean time.

I am a competent DIYer but do not know a great deal about electrics although I do fully understand the risks involved.

Can anyone suggest where I should start to look with this problem.

Thanks,

PG

 

[Adam_151]

What actually trips on the fuse box?, have a look at the device on the fusebox that trips and post back what the writing on it says, then when we know what trips, we can try and work out what the builder has done to cause it....

 

[JohnD]

The builder claims that there is nothing wrong with his electrics

PG

Almost certainly not true. I wouldn't get him back to do the rectification if he can't be trusted.

I hope he hasn't been fully paid yet?

 

[Qedelec]

Is he registered with an approved scheme to do electrics or is he basing his expertise on the years he's been doing it

 

[delmel]

Typical builder remark. It is unlikely to be the fuse board, it may well be that the protection device is being overloaded. Is it the circuit that cuts off or he whole fuse board.
Check the loadings (what lights and wattage is being run )on the circuit against the device protecting the relevant circuit. My guess is that he has possably overloaded the circuit and maybe even the cable (what size cable is being used).
Can you have each of the lights turned on and working one at a time.

 

[JohnD]

What kind of lamps are you running? Are they like ordinary 100watt bulbs, or are they huge halogens or infra-red heaters?