Low Volt Transformer

[laketime]

A customer has a cheap plug in transformer. The receptacle that it plugs into works fine except when he plugs the transformer in. Then the voltage at the receptacle drops to 19v. What is going on there?

 

[mkgrady]

A customer has a cheap plug in transformer. The receptacle that it plugs into works fine except when he plugs the transformer in. Then the voltage at the receptacle drops to 19v. What is going on there?

I would guess something wrong with source to recept. What happens when you plug in a table lamp. Does the bulb burn bright?

 

[laketime]

Good call...dimmer was bad for it.

 

[GoldDigger]

Good call...dimmer was bad for it.

You should never use a line dimmer to feed a general purpose style receptacle outlet. Neither UL nor NEC allow that.
There is a product which uses a special variation of the standard 120V three wire receptacle which does not allow an ordinary plug to mate with it.
You use a matching custom plug end on the attachment cords of lamps (table or floor) which can work safely with a dimmer.

 

[texie]

You should never use a line dimmer to feed a general purpose style receptacle outlet. Neither UL nor NEC allow that.
There is a product which uses a special variation of the standard 120V three wire receptacle which does not allow an ordinary plug to mate with it.
You use a matching custom plug end on the attachment cords of lamps (table or floor) which can work safely with a dimmer.

.

I would agree. I'll throw in the relevant NEC reference, 404.14(E) and 406.15. The only one I have seen is Lutron that makes such a device that makes this compliant (for plug in lamps) in the way you mention. That said, I wish I had a dollar for each of the standard receps. I have seen over the years connected to a dimmer. Usually, at some point in time, leads to an issue like the OPs where the user is unaware that there is a dimmer supplying the recep.