Halogen lights half off

Sep 23, 2005 17 Replies

Last night my electrics tripped (lights). On resetting the fuse only 3 of the 12V 20W lights came back on. Bulbs seem OK. Can the transformer half fuse? why have only half gone off?do transformers divive into halves-and do they break?. Problem is they are the type that are set into the ceiling and it will be a pain to get at the transformer!. any help or advice appreciated



transformer

I would imagine the lights are split between two transformers, one of which in a fit of spite in it's death throws tripped your fuse.

AWEM

Are you sure you don't have more than one transformer ? They're not rated all that highly due to limitations on the current load. Three of your bulbs pull 5A, the same as most entire mains-fed circuits.

Quite often the cheap ones are 3 lamps per transformer. Measure the voltage across the lamp terminals. If it is 0v you have two choices to access the transformer: from above or below.

Is there a loft above the lights or are their floorboards in a room above? Floorboards aren't too difficult to get up unless they are tongue and groove, in which case you'd almost be better cutting a hole in the ceiling.

Suitable transformers are available from toolstation.com part numbers:

55497, 67666, 28118

Mr F.

On Fri, 23 Sep 2005 10:01:41 +0100, John Laird scrawled:

Sounds likely to me.

Well, they may not be as common as the 3 lamps per transformer sets or the individual transformer per light arrangement but you can quite easily get 500VA transformers and drive 10 lights off one. Only the not highly rated ones are not highly rated. ;)

No doubt. But what sort of cable can you get that can carry up to 40A ?

Can't believe I asked that ! You just connect up several in parallel, of course.

Doh.

On Fri, 23 Sep 2005 18:10:43 +0100, John Laird scrawled:

Depends how far you want to carry it. ;)

With the correct fuse in each circuit.

Or buy some...

Car speaker cable would probably do 100A easily.

Car jump leads will do about 400A.

The croc clips might short together when you clip them onto the light fittings, but you can always cut them off and taper the conductor strands down to something that will fit the terminals..... NOT!

Chris

Of course you can!

Any transformer that is rated at 40A will come with connecters adequate for the job.

100A mains feeds to a house are not uncommon.

The wire exists, the connectors exist. When connecting to LV lamps you start them anyway mostly - so the final feeds are lower current.

100A is not really THAT much.

Sorry, I thought you were joking, and was simply joining in the fun.

I thought tapering the strands was about as acceptable as those old ceramic Screwit connectors.

OK, I see that makes sense, but if for lighting, it is possible that it has been assumed that the wiring will be run to individual lights in parallel, and thus a number of small connectors provided.

Run that last sentence by me again?

Chris

s/start/star

?

Sorry to sound stupid here but there are 6 x 20 bulbls , if I buy a new transformer the ones advertised come as 105W, or 150 W. Wish do I need

On 27 Sep 2005 02:58:52 -0700, " snipped-for-privacy@pensbyboys.wirral.sch.uk" scrawled:

The clue is in the question. Have you actually found a transformer and tested it in situ yet?

Sorry Again. Want to buy one of

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Can't test it before I buy!

On 27 Sep 2005 05:02:07 -0700, " snipped-for-privacy@pensbyboys.wirral.sch.uk" scrawled:

But that's not the one in your kitchen which is the one that needs testing.

I suggest you call someone in as basic comprehension is lacking here and is a bit of a hindrance.

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