Help with lighting issue

[mt29]

Hi, i have a bar that has outside lights consisting of 12 x 70w sodium lights and 5 x 40w pendant lights. They have worked fine for months but last week for no apparent reason the B10 breaker tripped. I reset it first time and all of the lights were still working, but then about 2 hours later they tripped again.
This time one of the sodium lights was not working so i took the bulb out and reset the breaker. It stayed on for two days.
I then put a new bulb into the light and all seemed fine for 1 day. But today the breaker has gone again. (I don't know of the bulb had anything to do with this).
The strange thing is that the lights are fine for hours and then suddenly go for no apparent reason. But always reset fine first time. I have tested each fitting and they are all getting 240v's also there is no sign of any water.
I have also changed the circuit breaker for a new one but this has not stopped the issue.

Any ideas would be appreciated.
Thanks

 

[ColJack]

as it's taking a while to trip then it's a small overload.. it'takes time for the breaker to heat up enough to trip out..

sounds like the gear is stuffed on that fitting.. ( do 70W's even have gear? I've never installed ones that small.. )..

 

[Spark123]

Could also be water getting into one of the fittings.
As it is a commercial premises I suggest you get a qualified electrician in to take a look.

 

[mt29]

Thanks for your reply Coljack. Sorry i don't understand what you mean by 'gear'?
Also if i am correct i don't even have 5amps on the circuit, so is there something else that could be causing an overload?

Thanks

 

[Spark123]

A 70w sodium fitting will have a ballast, a powerfactor correction capacitor and depending on lamp type an ignitor.

In use your circuit can pull anywhere up to 7.5A, this figure should drop off a bit as the lamps warm up, but not as low as 0.3A for a 70w SON.

 

[mt29]

Thanks Spark 123, i know from buying the new bulb that the fitting does not have an ignitor. Do you think there is an overload issue?

Also in your opinion if the fitting was faulty would it still work (as at the moment all lights work until the breaker trips).

Thanks

 

[Spark123]

It depends what is at fault, I have known capacitors get water in them and cause an overload.
If a ballast has burned up you can usually smell them when opening the fitting, then taste them for the next 3 hours.

 

[Lectrician]

It's not an overload. It is likely a faulty fitting - You should be able to spot which one if you take the covers off.

You should have a C10 breaker really too - although it seems you have not had any trouble with startup currents tripping the B type breaker.

This also goes to prove that more circuits are better than 1. If you have a fault, you do not loose all your lights.

 

[mt29]

Thanks, tomorrow i will open up the fitting and have a look. The fitting is only about 2 months old so i will take it back if it is faulty.

Hopefully it is that fitting otherwise i will call out an electrician.

Thanks