light bulbs keep blowing...Why?

[timmy123]

I was called to a large pub today where they have 2 particular lighting circuits where the bulbs are failing/blowing on a daily dasis. The lights are all mains voltage ( none 12 volts). The 2 circuits are protected by 10 amp type C MCBs . I have added up the total wattage of lamps on each circuit and they are both around 1.5 kilowatts each.
The problem only started recently. The only recent change has been a new chandelier type light has been added to one of the circuits. This contains 6 x60 watt lamps and I have included this is the total load on each circuit. The client also tells me that he has not made any changes to the type/make of bulbs he is using.

Every time a bulb blows it is tripping out the MCB on its circuit. There are no RCds involved.Each lighting circuits each has a dimmer unit and these units have been in place a long time prior to the problem starting.

Any suggestions would be greatly appreciated as the landlord is changing half a dozen blown light bulbs each day!.

Many thanks.

 

[mnbs 4x4]

i remember years ago i had a job that kept blowing lamps, turned out the customer had purchased a box of 110v lamps instead of 240v ones, that could be worth checking.

 

[timmy123]

Thanks sparkinlee for your reply. I am going back to this pub next week and will do the tests you suggest. Many thanks again

 

[cbw]

It may just be that the original bulbs are now all reaching the end ot their useful lif, hence several blowing around the same time?????

 

[UNG]

It may just be that the original bulbs are now all reaching the end ot their useful lif, hence several blowing around the same time?????

How many lamps actually last for there rated hours these days. I tend to date mark lamps where I am getting problems to keep a check on lamp life as many fail before getting any where close to the hours they are rated for especially the CFL's which seem to be very hit and miss on how long they will last with very few hitting 8000 hours

 

[ian.settle1]

i remember years ago i had a job that kept blowing lamps, turned out the customer had purchased a box of 110v lamps instead of 240v ones, that could be worth checking.

They would go bang as soon as they where energised.

 

[Adam W]

They would go bang as soon as they where energised.

Not if they were dimmed, which is probable in a pub.

 

[timmy123]

Apologies for not replying sooner to your reply but been working away from home. Many thanks for your information and I am oing back to this pub later this week and will try whqat you suggest. Cheers again.