Light Transformer Wiring Problem

[homerisgod]

Untitled

• homerisgod
• 23 Mar 2014
• 1

Please see the image. I have connected the Live and Neutral supply wires into the corresponding Live and Neutral terminal blocks of the transformer. The transformer came with a wire attached to the output part of the transformer as shown in the picture. The light fitting that came with the transformer has one brown wire which I presume goes into the other output terminal? What the bloody hell do I do with this short wire? Do I need to connect that into the terminal with the brown wire from the light or is just a spare output in case I wanted to connect to something else?

Any help much appreciated.

 

[EFLImpudence]

The light fitting that came with the transformer has one brown wire which I presume goes into the other output terminal? What the bloody hell do I do with this short wire?

There will be an empty terminal on the light, won't there?

 

[PrenticeBoyofDerry]

The transformer came with a wire attached to the output part of the transformer as shown in the picture.

This blue core goes to the neutral side of the lamp/fitting

The light fitting that came with the transformer has one brown wire

Which is the live line and connects the the live on the secondary/load side of the transformer

which I presume goes into the other output terminal?

Yes that is correct, it goes to the secondary side of the transformer

What the bloody hell do I do with this short wire?

as above it is the neutral of the secondary side of the transformer and goes to the neutral terminal of the light.

Do I need to connect that into the terminal with the brown wire from the light or is just a spare output in case I wanted to connect to something else?

No it goes to the neutral of light

Blue = Neutral
Brown = Live/Line

Any help much appreciated.

No worries, hope this was helpful?

 

[Taylortwocities]

I'll try not to confuse you further.
But in response to PrenticeBoyofDerry last post. The output of the transformer (secondary) does not have a LIVE and a NEUTRAL.

There are two terminals on the transformer marked
"SEC 11.5v".
There should be two wires from your light fitting. Connect the two wires to the transformer. Any way round, any colour, it just doesnt matter.

 

[ericmark]

Four wires two in already connected and two out to extra low voltage lamp as said either way around no polarity on separated extra low voltage.

 

[Robin0577]

Could we have a picture of the light fitting as well please?

The OP has indicated that the light fitting is provided with only one wire (brown) and given that there must be a return path somewhere I would suggest that there must be a terminal somewhere on the fitting to accommodate that short blue wire from the transformer. (Is it possible that the manufacturer has decided to use the metalwork of the fitting for the return connection?!? I suppose that is considered acceptable practice for SELV?)

 

[EFLImpudence]

The OP has indicated that the light fitting is provided with only one wire (brown)

As I read it he has one wire on the light fitting and another on the transformer (in the picture).

and given that there must be a return path somewhere I would suggest that there must be a terminal somewhere on the fitting to accommodate that short blue wire from the transformer. (Is it possible that the manufacturer has decided to use the metalwork of the fitting for the return connection?!?

Some do but there still has to be two wires from the transformer.

I suppose that is considered acceptable practice for SELV?)

It must be but, even though there is a cover, as the Live could come out and contact the metal ceiling fixture which is connected to the light fitting it does not seem ideal.

 

[JohnW2]

(Is it possible that the manufacturer has decided to use the metalwork of the fitting for the return connection?!? ... I suppose that is considered acceptable practice for SELV?)

It must be but, even though there is a cover, as the Live could come out and contact the metal ceiling fixture which is connected to the light fitting it does not seem ideal.

I'm a bit confused. If the transformer pictured is part of the light fitting, can the fitting as a whole really be regarded as SELV - given that there is an LV cable entering it and just terminated by screw terminals in a connector block (and not even any apparent cable clamp). As you say, one of the LV conductors could theoretically come adrift and touch anything - including any metalwork of the fitting. Does that really qualify as SELV?

Kind Regards, John

 

[Robin0577]

Some do but there still has to be two wires from the transformer.

Yes, of course, my speculation was that the brown flying lead attached to the light might attach to the presently vacant transformer terminal providing a supply and that the blue flying lead from the transformer might attach to a fixed terminal on the body of the light to provide a return.

I agree that it seems to be a far from ideal design and without seeing the rest of the fitting it's pure speculation but it would be a possible explanation for having one flying lead attached to the light and one to the transformer.

 

[securespark]

Those fittings are Class II.

As you can see from the transformer block, there are clamp fixing points, but I have yet to find one of these fittings that has had them fitted.

 

[JohnW2]

Yes, of course, my speculation was that the brown flying lead attached to the light might attach to the presently vacant transformer terminal providing a supply and that the blue flying lead from the transformer might attach to a fixed terminal on the body of the light to provide a return. ... I agree that it seems to be a far from ideal design and without seeing the rest of the fitting it's pure speculation but it would be a possible explanation for having one flying lead attached to the light and one to the transformer.

Sure, but is it possible that there is an 'undiscovered' (or, at least, not so far mentioned) terminal on the light fitting (connected to the lamp, not the body of the fitting)? People are calling them 'flying leads', but the one we can see (at 'transformer') appears to have a screwed connection to one of two terminals. If it were the same at the light end (i.e. two screw terminals), it could just be that, for whatever reason, for the purpose of shipping they disconnected one wire at the 'transformer' end and the other wire at the light end?

Kind Regards, John

 

[Robin0577]

Absolutely possible John, without a picture of the other part we're all in the dark really.

Terrible pun alert

 

[winston1]

It is NOT a transformer, it is a switch mode power supply, it is wrongly labelled. That said there are 2 output terminals one with a wire already connected. The 2 output terminals go to the 2 connections on the light.

 

[ericmark]

(Is it possible that the manufacturer has decided to use the metalwork of the fitting for the return connection?!? ... I suppose that is considered acceptable practice for SELV?)

It must be but, even though there is a cover, as the Live could come out and contact the metal ceiling fixture which is connected to the light fitting it does not seem ideal.

I'm a bit confused. If the transformer pictured is part of the light fitting, can the fitting as a whole really be regarded as SELV - given that there is an LV cable entering it and just terminated by screw terminals in a connector block (and not even any apparent cable clamp). As you say, one of the LV conductors could theoretically come adrift and touch anything - including any metalwork of the fitting. Does that really qualify as SELV?

Kind Regards, John

I am with you there John the power supply may be Class II but that does not mean the lamp is Class II. Unless there is a

sign on the fitting then earth is required even if the electronic unit inside the fitting has a

mark on it.

As to word "Transformer" it transforms a 230vac 50Hz supply to a 12vac supply so although it is not what we would normally consider to be a transformer it could not be considered wrong it does transform. I would agree power supply would be a better description but be it by simple induction or using a switch mode power supply it does transform and isolate. Poor chap can't work out how to put two wires in two holes and your trying to explain the difference between switch mode and simple inductance come on.

 

[Taylortwocities]

It is NOT a transformer, it is a switch mode power supply, it is wrongly labelled. That said there are 2 output terminals one with a wire already connected. The 2 output terminals go to the 2 connections on the light.

Oh, not that arguement again. OK, here goes.

transformer
transˈfɔːmə
noun
1.
an apparatus for reducing or increasing the voltage of an alternating current.

By definition, that box is a transformer. Voltage can be transformed (increased or reduced) in a number of ways.
One of the ways is having a number of wire windings on a common core.
Another way is to use electronics, such as a switched mode power supply.