Dodgy Flood?

[DanielArkley]

We were rigging up some floods at school on Thursday, and I was rather horrified to find that when we went to test one of them by putting it on full override on the dimmers, the circuit breaker tripped out. I reset the breaker, and tried again, and it tripped. Again.

 

The flood is a 500W CCT, and was on it's own channel on a Pulsar Pack (5A channels). I guess it's a fairly safe bet to say the lantern is stuffed up?

 

Thanks

[timmath]

Did you have all the lamps on the dimmer on at once or is it just the one lamp? if it was all the lamps you may have overloaded the trip. otherwise the following steps apply...

 

If you unplug the flood on the bar, power up again and the trip stays in then its not the cable to the bar or the dimmer...

 

If the trip pops out again, unplug the cable from you dimmer, power up again if the trip stays in then its not the dimmer... but could be the cable linking the lantern to the dimmer

 

If the it's not the dimmer then plug the flood directly into the dimmer, if it trips then is the lantern - if it doesn't trip then it's the cable from the bar to the dimmer.

 

Incidently does then lantern have a valid PAT sticker on it?

 

Regards

 

Tim

[Just Some Bloke]

There is not much to go wrong with floods, if that is what is causing the problem.

 

Check the following, in this order:

 

1) Connections in the plugtop

2) Any breaks in the cable which may be making it short out?

3) Look at the state of the lampholders. Do they look like they've been arcing? (i.e. are they looking a little burnt?)

 

These can all be fixed quite easily and cheaply:

1) Rewire the 15A or 5A plug if necessary

2) Replace the cable if necessary

3) Order a new pair of lampholders and fit them if old ones aren't right.

4) If none of these seem to be the problem show it to an electrician.

 

Each of these is much cheaper than throwing the unit away and buying another.

 

Good luck!

 

JSB

[robloxley]

Incidently does then lantern have a valid PAT sticker on it?

Err, how does that help?

 

Also if you've managed to trip something out, I'd strongly advise against plugging the same things back in, in any order, to locate the problem - the trip has gone to protect you from a fault!!! Get the lantern and cable looked at and if that doesn't show anything I'd get someone to look further into things like the dimmer etc.

[richard]

I think that the point of whether it has a test sticker would bve to see if has been tested recently, if it had been then you would know if it has been looked after.

 

The point of testing it by plugging the lamp back in is a good one, often there are times when a bad actual bulb (or lamp) will take the breaker out once or twice, and then blow, after which it will work, or the fault could be on the cable rather than the lamp (but triggered by the lamp) in which case the series of steps above would be of use to isolate that fault.

[robloxley]

OK, the pat test sticker tells you it was fine last week. So what? It could still be lethal today.

 

A live-to-case fault, for example, would certainly cause the breaker to trip. Doesn't sound like too much of a good idea to me to keep plugging that lantern back in.

 

What kind of breaker exactly is tripping?

[Matt]

I can safely say dan, thats one of our floods :blink: sorry we had the problem, though we dont know why it did it every time, guess we just didnt pick it up when we left, your welcome to it ;)

 

we thought it as were the wire entered the casing of the lantern, but if the wire itself looks damaged (def ours) then the insulation inside could be split and that could be tripping it out, though checking the cable should be one of the first things you would do to see why it aint working, did the light actually come on at all?

[DanielArkley]

I can safely say dan, thats one of our floods :blink:

Erm. It's not one of your floods! We've had 5 floods since before I even met you at Barnum.

 

As for the PAT test sticker, I will have a look tommorow, but I believe it's fairly recent.

 

I'm not sure what kind of breaker it is. It's in our junction box, and I believe its 30A. The breaker only goes when I use this specific lantern. The dimmer was switched on, and other lanterns had been running from it. It was only this specific lantern that caused it to trip.

[Matt]

I remember looking at your breakers :blink: and I think they were 30a (as u said) 10ma trip, so they would be more sensitive than the fuse when current is leaked through the earth, I'd suggest getting a qualified person to pat test the light again, see what is actually happening with the earth, then completely take it aprat and check everything and then rebuild it.

 

well... you dont even have to pat test it, just use a continuity tester between the wires, live+earth neutral+earth live+neutral... probably much quicker than aranging a pat test... get the tester from your science department or something ;)

[Ben]

might seem like a silly question but are you sure that it is the flood that is causing the trip and not an internal fault on the dimmer?

quickest way to check this is to cross plug with a lantern you know to work and see if it trips, if so the flood may well not be the problem.

just a thought