Transformers

[studentspark]

Is a standard electronic transformer OK to use for ELV garden lighting if it is in a suitable IP rated enclosure.

50w halogen lights

Just reading about outdoor transformers and they suggested 'potted transformers' due to possible condensation problems.

Problem is these are quite expensive and I need to put a few in.

Seven lights, which I was going to put on own transformers, due to cable length issues, which I understand roughly as about 3m for 1.5 and 6m for 2.5

Thanks

 

[conny]

The slightly higher costs of potted transformers far outweighs the costs of repeatedly replacing unpotted ones and are much safer as the compound is not combustible until it reaches a very high temperature.

 

[bernardgreen]

For outdoor use I would ( and have ) used a wound transformer to supply 12 volt lighting units with the transformer in a suitable housing that adequately protects it from the weather. And located where the minimumm on 12 volt cable runs are needed.

Something like this

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=3618020

( first image I could find, there are other types manufacturers but Block are very good quality )

Advantages are only one circuit route at 230 volt and total ensured safe isolation of the ELV ( 12 volt ) supplies to the lighting units.

Dis-advantage is the inrush current to the transformer may require a type C circuit breaker and may lead to increase wear and tear on the switch.

If you can use 24 volt lights then the ELV cable can be smaller cross section ( or the same cross section and longer for the same volt drop ).

 

[studentspark]

Thanks for the replys

24v Garden lights don't seem to be that widespread, (google search)

 

[efiste2]

This one we have just removed will allow you to use as many 240V lamps in your garden as you need, it is self cooling and is quite weatherproof and can easily be hidden by tress and shrubs.......and your welcome to it....Ill even throw in the switched spur too......Only niggle may be getting it wired into the ring main but your local DNO should be able to advise you on that one....

 

[bernardgreen]

This one we have just removed

Does the owner know you removed it ?

 

[efiste2]

Oh yes its a legal and above board....we can deliver it too...we actually have to pay the scrap man to take them away..

 

[sparkydude]

Just leave it in the street , the local 'travellers' will soon assist you with the removal of said item





Nick

 

[conny]

Oh yes its a legal and above board....we can deliver it too...we actually have to pay the scrap man to take them away..

If you were to drain the oil from it then remove the windings so you had the metal casing and the copper separate the scrappy would pay you if you were to drop it off at their yard.
They probably don't want the trouble/have the facilities to drain the oil.

 

[ban-all-sheds]

PCBs?

 

[Stoday]

PCBs?

PCBs were more expensive than oil and were only used for indoor transformers where the fire risk had to be accommodated. E.g. in a factory area and not in a separate substation attached to the factory.

The transformer in the illustration is a rather ancient but otherwise standard oil filled 500KVA or so.

 

[westie101]

They probably don't want the trouble/have the facilities to drain the oil.

We recycle all the oil within the company so do not let any of it leave us. (apparently it would also be in breech of some environmental law if we did anyway)

 

[efiste2]

(apologies to have hijacked the thread Mr Moderator) That Transformer weighed about 4.5t inc the oil and was i recall, 75 years old and one of a few left that have the HV & LV bushings out of the oil.....it also had a very low level or no PCB's in it at all.... known PCB transformers in SP (Manweb) have been tested and any above a certain level have been removed from the system. I have encountered outdoor transformers with PYROCOLOR in which i beleive is a PCB, but not for a long time.....Usually today any transformer in a S/S that is incorperated in a bigger building is filled wit MIDEL oil.

 

[ban-all-sheds]

It won't have been PCBs, because they don't do that, but something has burnt that poor bu**er's face clean away....

 

[efiste2]

LOL....