Lamps blowing and tripping MCB

[sherman0251]

I have 2 lighting circuits. One feeding kitchen, garage and utility. One feeding lounge, diner and bedrooms.
I installed a new 3 way GU10 halogen fitting in the kitchen approx 3 months ago, since then the individual GU10 lamps are blowing almost every week, In turn it trips the MCB. There are candle bulbs in the remaining fittings in the house and they too pop reguarly causing the MCB to trip. Please note (not an RCD). All lamps installed are a decent make i.e osram, philips. Any ideas why they would keep blowing???

Cheers

 

[riveralt]

I have 2 lighting circuits. One feeding kitchen, garage and utility. One feeding lounge, diner and bedrooms.
I installed a new 3 way GU10 halogen fitting in the kitchen approx 3 months ago, since then the individual GU10 lamps are blowing almost every week, In turn it trips the MCB. There are candle bulbs in the remaining fittings in the house and they too pop reguarly causing the MCB to trip. Please note (not an RCD). All lamps installed are a decent make i.e osram, philips. Any ideas why they would keep blowing???

Cheers

It is highly likely that an MCB will trip when a GU10 bulb goes so that is not necessarily the issue - though see later. The MCB protects against overcurrent - the RCD protects against faults to earth.
Reasons for blowing:
You could have a bad batch.
You could have bought the wrong GU10 for your light fittings - Cool beam instead of Aluminum.
As a consequence you may have damaged the fitting itself, particularly the ceramic holder for the pins which can crack very easily.
You could have a loose cable which gets worse as it heats up and causes the bulb to blow - this could be anywhere on the circuit even at the point of origin, the Consumer Unit.
Halogen bulbs only have a relatively short live span.
You could have the wrong light fitting for the environment it is in - e.g. kitchens or bathrooms generate a lot of steam and this can cause problems with your unprotected lighting equipment.

 

[Taylortwocities]

......and/or

Your supply voltage is too high
You have high voltage spikes on yoru supply (unlikely)
There is lots of vibration from the floor above - household halogen lamps do not like being banged around when they are lit (unlike car headlamps).

 

[sherman0251]

Thanks for your replies!!
I have already carried out a periodic inspection on the property, everything ok and within limits. I have measured the current in the circuit which is about 4 amp.

I have told the customer I am going to go back next week free of charge for them and test both circuits again in case I have missed something???

Appreciate any more help or advice???

 

[JohnD]

how many lamps are there in total?

 

[sherman0251]

on circuit 1, there is about 20ish 40w candle bulbs.
On circuit 2 there is 10 X 50w MR16's 1 4' fluorescent and 3 50w GU10 (the kitchen)

Cheers

 

[ban-all-sheds]

I have told the customer I am going to go back next week

Take a C6 with you.

(Or a cartridge fuse carrier and a few spare fuses for it )

 

[JohnD]

'mmmm. 33 bulbs, none of them CFLs. They are going to experience lamp failures relatively often, then.

 

[sherman0251]

Am i right in saying that C type have a slower reaction time of around 1.3 times slower than B? What do you think my problem could be though? Im pulling my hair out. Lol

 

[sherman0251]

I have told them that they have a large quantity of lamps and therefore will experience more lamps blowing, but the fact that there lamps are popping every other day throughout the house, more so in the kitchen baffles me?

 

[Adam_151]

Am i right in saying that C type have a slower reaction time of around 1.3 times slower than B? What do you think my problem could be though? Im pulling my hair out. Lol

No, not slower, just less sensive, the current value at which the mag trip opperates is approximatly twice that of the same rating B type

(naturally it follows that your allowable loop value is halved, so be sure to check zs)