football club floodlights

[AADES]

Hi all first post so go easy

Called in to look at above which had gone off before Christmas. One ballast had disintegrated blowing main 150A fuse. Ballast replaced new fuse fitted all fine.
Yesterday no lights again. This time lamp had blown and again 150A fuse had blown.
My question is why is 150A fuse blowing and not overload breakers at each floodlight or RCBs first.
Floodlights on both occasions were at full capacity and my initial thoughts are due to heat and load at the time the fuse is the weakest point ?

 

[stuartcourt]

what size breakers at floods to lamp size and how many in all

 

[AADES]

16a individual breakers 40 2kw lamps on 3 phases with 150a fuse on each phase which is the one that has blown twice.

 

[Tim]

Is it the same circuit this has happened on each time? Could be a faulty breaker

 

[D Skelton]

The caps are going. The 16A breakers for each fitting won't notice this but I'll be willing to bet that you're probably looking at a current P.F. of 0.7 per phase or less! Check the caps!

 

[Knobhead]

16a individual breakers 40 2kw lamps on 3 phases with 150a fuse on each phase which is the one that has blown twice.

If anyone would care to do the calculations. 40 X 2KW = 80KW = 116A per phase. Add the start up current for the fittings?

Install a staggered start up for the lighting.

 

[D Skelton]

If they have been fine up to now though Tony then surely the start up current isn't an issue for the fuse. I still stand by what I say, if those lights have been there for 5-10 years already then I wouldn't be surprised if over a third of their caps have gone resulting in an abismal P.F. hence the main fuse popping now. Seems to me to be a 'straw that broke the camel's back' situation going on here.

 

[Knobhead]

True and testing the PF correction would be the thing to do. A staggered start up (balanced across the phases) removes another problem.

Without some info from the OP we may as well give up. As usual.

 

[D Skelton]

Without some info from the OP we may as well give up. As usual.

That would help! lol

 

[AADES]

Sorry for the delay in replying guys and thanks for all your comments. I did further checks and half the crimped connections on the caps had rusted
and fallen off ! Under plastic covers so didn't initially notice. Thanks D Skelton good call. Tony staggered start in place so discounted that at start but thanks. Checked all the
Others and half of them are about to go too so company have agreed to replace all connections (only 3 years old)