help with fridays work scenario

[Ste69]

Scenario

There is a bank of 6 light fitting with two tubes in each (58w floursent T8 tubes controlled by one 2x58 watt ballast) they are plug connected in each fitting and each fitting is protected by a 3 amp fuse. The 6 fittings are fed from a canalist (sorry if this is not correct terminology, this is what i know it as at work) plug set up in the ceiling and the whole lot is protected by a 10 amp fuse in the canalist plug.

I was called to a fault at work were all 6 fittings were out, i traced the cable back to the canalist plug and checked the fuse and replaced it as it had blown......so got 5 fittings working, went to the fitting that was still off, changed control gear and everything is now working fine......so it was a faulty ballast that caused the problem.

Ok so alls great BUT i want to know why the 10 amp fuse in the canalist plug blew before the 3 amp fuse in the fitting?

Cheers

 

[Plonker 3]

What type of fuses were they, and were they both the same type?

 

[Ste69]

mmmmm good question, sorry all i have is cartridge fuse 10amp and 3 amp.......i will get more information for you next visit.

 

[Silly Sausage]

Don't really know but it might be something to do with them being over stressed from previous faults.
Had it at home once, a dead short on a dieing(? spelling Geordie!) cable was blowing out the old rewireable until finally the 100A main fuse went leaving to 30A fuse wire intact.

 

[Plonker 3]

Its all about the characteristics of the fuse, look in appendix 3 of the BGB to give yourself a better idea about them.

 

[Ste69]

Don't really know but it might be something to do with them being over stressed from previous faults.
Had it at home once, a dead short on a dieing(? spelling Geordie!) cable was blowing out the old rewireable until finally the 100A main fuse went leaving to 30A fuse wire intact.

I though about that, old fuse, losely plugged in maybe......if all the fittings had came back on with replacing 10 amp fuse i would of thought that BUT with one fitting being off still means the fault came from that fitting and should of blown the 3 amp local fuse...

 

[Ste69]

Its all about the characteristics of the fuse, look in appendix 3 of the BGB to give yourself a better idea about them.

Excellent! certainly will.....cheers Dillb

 

[pennychew]

Is the canalist plug set up similar to the Hager Klik stuff?

 

[Ste69]

Is the canalist plug set up similar to the Hager Klik stuff?

Just googled hager klik and yes it is similar to that mate.......

 

[Ste69]

though its a little different, maybe an older type click system, its not as smooth as the hager klick stuff.....

 

[pennychew]

either way its a result when you're changing a ballast in a shop/factory and you see one above the ceiling! saves all the women whinging on when youre trying to find the right breaker!

 

[Ste69]

either way its a result when you're changing a ballast in a shop/factory and you see one above the ceiling! saves all the women whinging on when youre trying to find the right breaker!

Ha!......to right mate......nowt worse than trying to find a db in an old building! (most of the time with no diagrams etc).....