spot light array problem Ask questions and find answers to many subjects relating to electrics and electrical work

[bobbyboy16]

Hi, Guys

Hve just fitted a new spot light array light in the kitchen area. I have checked wiring twice by removing and fitting, which is a right pain with the weight of the transfomer in the unit. All seems ok to instructions

The problem is it keeps tripping the circuit breaker when we switch on sometimes and more when we switch off . The breaker I must admit is pretty sensitive ( goes off even when a bulb goes on the circuit)

Any suggestions, Is the unit working. Some one mentioned it could be the he transformer current/voltage dump tripping the circuit. I have spoken to the supplier, but he says they have never been any reported problems re: the transformer causes problems on the circuit

Any help would be appreciated

[333rocky333]

Look on mcb is it type B or C usually marked in front of the number i.e.B6 B10 C6 C10.

It sounds like inrush of transformer, type B mcb more prone to tripping because of it.

Fitting a soft start dimmer COMPATIBLE with the light may be the only way round it, or replacing transformer with a different type .

[ericmark]

You say circuit breaker and I assume that is the MCB for lights only. You also say spot light array so I assume quite a few lights.
It is not normal for a 6 amp type B MCB to trip with up to 4 x 50 watt bulbs but if there are more than that you may be overloading circuit by time one includes other bulbs in the house so how big is the array and does it still trip out when all other lights in the house are off?
It is tripping when you switch off that puzzles me! Could you be talking about a RCD? Is there a yellow test button on the circuit breaker you talk about?
Since only houses with TT supply normally have RCD's fitted to lighting circuit it is possible the supplier would have not come across the problem before. (TT supplies use an earth rod does not really matter to you what it is except that you end up with a RCD on the lights.)
I have found although RCD's have tested OK with special meter and replacement RCD has tested out with same results that they have been faulty and changing RCD has cured the problem.
MCB's can also get tired if they trip out a lot and sometime require changing.
Since RCD's need testing with special meter after fitting I would recommend if you think this may be faulty it is not changed by non electrician.
If it were mine I would wire it to a 13 amp plug with 3 amp fuse and see if when used that way if it blows fuse or trips RCD but I am loathed to recommend that method to a DIY person in case you make a mistake. Maybe you have an electrical friend who could bench test it in that way? A two amp fuse maybe better test than 3 since 230 watt is 1 amp even a 2 amp fuse is well over what it should use and if it did blow the fuse then you can also demonstrate to the supplier it is faulty.
It is normal for a MCB to trip when low quality bulbs blow. Often when a bulb blows one gets ionization inside the bulb which causes a short circuit for a few seconds more expensive bulbs has fuse built into them.

I will watch and see your answers with interest. Eric

[333rocky333]

I was going by his quote
weight of transformer
sounds like a wire wound transformer
We use a lot of these in pub work and we find most when over 200 va trip the mcbs, manufacturers are now making them soft start now.

[bobbyboy16]

Thanks Guys,

I will check the type of breaker out, but I think as you have discussed its and MCB.

I will let u know outcome