Why are my lights tripping?

[attractivebrunette]

Okay guys, I've had a consumer unit put in and since then I've put up some 12V track lighting in the hall and two of the bedrooms which are all on the same 'lighting' circuit.

However, more often than not, when I switch on the lights in...

1. Hall
3. One of the bedrooms

...that particular circuit trips out. The other bedroom is fine and never trips out, even though it's on the same circuit and also has 12v track lighting.

When I try putting the circuit back on, it keeps tripping out a few times before eventually it will come on with all those lights on. It comes on quicker if I flip the switch for that circuit slowly.

So in other words, the lights for all these areas do work at the same time, but it's when I actually try switching on one of these sets of lights that this circuit trips.

So I isolated each of the problem areas one by one, but the set of lights in the two problem areas still nearly always trips out the circuit even when the others are off the circuit.

The Hagar switch says it's a 106 for this circuit. Incidentally, I have another set of 12V lights with a circuit all to their own and these are also on a 106 switch and these also nearly always trip out.

But the sockets for the house are on a 132 circuit. What does the 106 and 132 mean? Can a 132 carry a greater load?

What's causing the problem? Is this particular lighting circuit overloading and I need a 132 switch instead?

But if so, why is this circuit not being overloaded or tripping out by the identical 12V lights in the other bedroom?

Help!

Untitled

• attractivebrunette
• 19 Oct 2012
• 1

 

[PrenticeBoyofDerry]

106 and 132 relate to the MCB rating 106 is a 6A MCB and 132 is 32A MCB.
What ratings are the transformers and what load are they taking?

 

[attractivebrunette]

CIRCUIT 1 6A
Hall (trips out the circuit) 8 x 20 watt bulbs (160w) on a 200VA transformer

Bedroom (trips out the circuit) 6 x 20 watt bulbs (120w) on a 200VA transformer

Bedroom (doesn't trip out) 5 x 20 watt bulbs) (100w) on a 100VA transformer

CIRCUIT 2 6A
Communal area (trips out circuit) 6 x 35 watt bulbs (195w) on a 300VA transformer

 

[ban-all-sheds]

Is this particular lighting circuit overloading and I need a 132 switch instead?

Do not under any circumstances change a 6A MCB to a 32A one on a lighting circuit.

 

[attractivebrunette]

Thanks for telling me what I should not do.

What do you think is causing the problem?

 

[plugwash]

When transformers are switched on there is an inrush current. Particually if they are real transformers rather than electronic "trasformers". I wouldn't normally expect it to trip a breaker though.

Personally I'd probablly try replacing the breakers with C6 breakers.

 

[attractivebrunette]

Yep, they're toroidal transformers. I guess it's telling that the 100VA one doesn't trip.

What's a C6 breaker and who do you think it might help?

 

[333rocky333]

The mcbs have it printed on them
likely to be
type C or type B
I can not read where you said they are not type C actually

OOh i see in the picture you have type B
Type C are more likely to absorb the inrush current, though certain tests like ELI are required before replacing with C type
You should have the ELI readings from the person who installed the Dist Board

wire wound transformers which you have are prone to tripping type B

 

[attractivebrunette]

Good stuff Rocky!

So should I get a sparky to replace the light circuits with 6A C type? I'm assuming not 32A C type.

But all only after I've either shown him the ELI results or he does them himself?

 

[333rocky333]

Yes, but you wont know till you try the C type if it cures it though.
If the inrush is still a nuisance last resort is you can put the lights via a FCU mounted next to the dist board fitted with a 5 amp catrtridge fuse,
This Fcu could be supplied by a larger cable and thus a larger mcb like a 20 amp, the cartridge fuse can handle even higher inrush.

There are also type D available but your ELI needs to be low to fit them

THe only thing you might find though is you cure the mcb tripping but it may then play havoc and trip the RCD even though its not an earth fault

 

[attractivebrunette]

This is the report I got when the Consumer unit was installed. Does it have the ELI results?

Untitled

• attractivebrunette
• 19 Oct 2012
• 1

 

[RF Lighting]

No, there should be a seperate page with the test results on.

Get a sparky in to confirm the efli value and then swap the breaker to a C6. Tell him it's a new style hager breaker so he can bring the right part with him.

 

[wundaboy]

Yes, but you wont know till you try the C type if it cures it though.
If the inrush is still a nuisance last resort is you can put the lights via a FCU mounted next to the dist board fitted with a 5 amp catrtridge fuse,
This Fcu could be supplied by a larger cable and thus a larger mcb like a 20 amp, the cartridge fuse can handle even higher inrush.

There are also type D available but your ELI needs to be low to fit them

THe only thing you might find though is you cure the mcb tripping but it may then play havoc and trip the RCD even though its not an earth fault

Are Hager BS1361 cartridge fuse modules still available? Replacing the offending breaker(s) with those might be a neater solution.

 

[attractivebrunette]

Thanks guys, these are the test results:

Untitled

• attractivebrunette
• 19 Oct 2012
• 1

 

[RF Lighting]

You should be fine looking at that. I'd still personally check it anyway just for piece of mind.