Discuss Weird Transformer Fault in the Electrical Forum area at ElectriciansForums.net

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AndrewMgan1976

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Just fitted a light for someone, one of these 5 way 12V 20w things with 105VA transformer in the base.

Put 1 lamp in and it lit very dimly, so checked the transformer and was getting nothing through it. Put in the other 4 lamps and they all worked perfectly.

Any thoughts on probable cause of the initial dullness?
 

pjcomp

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Transformers are usually valid from a low VA to a high one, eg 20 to 105. Which means it won't work if the draw drops below the low number. Could be this one was a bit fussy, or might be 25-105 (unlikely).

PJ
 

darkwood

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Its an electronic transformer it will specify min and max wattage... you are under the min' threshhold so the electronics will not power the secondary side up..... RTFI - Read The Instructions is the term i was always taught. ;)
 

darkwood

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Andy have you read the minimum load usually printed on the transformer itself.... What does it say! As said before if you go below this the output voltage is cut... although not always fully you may get a leakage hence the dim glow.
 
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AndrewMgan1976

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Andy have you read the minimum load usually printed on the transformer itself.... What does it say! As said before if you go below this the output voltage is cut... although not always fully you may get a leakage hence the dim glow.
I didn't notice it and the person didn't have the instructions. She had tried to fit it herself after watching youtube videos!!
 
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