Lights dimming inversly

[domelectric]

At a upscale restaurant on St Armands Circle I ran into this crazy situation that still has me befuddled. Three track lights on one dimmer. Dim the lights and two lights dim, one goes full bright. Toggle the dimmer and the two lights go bright the third dim. Bypassing the dimmer results in the two lights full voltage, the other zero volts. There's the same exact situation at another part of the restaurant, different circuit, different dimmer. I remain clueless. Oh, I cannot see any wiring above the ceiling, but there is a box somewhere because each light has only one SL going to it.

 

[mdshunk]

Two circuit track with a loose neutral?

That is a weird problem.

 

[domelectric]

Ive checked all the grounded wiring in the panel. Nothing loose. Cant say for sure about the buried box though.

 

[480sparky]

A 2-circuit track could have a loose neutral anywhere, not just in the panel.

 

[domelectric]

Agreed, but I still cannot seem to grasp how one light dims while the other two go bright.. and vice versa.

 

[Dennis Alwon]

Are these low voltage tracks. Some magnetic and low voltage transformers must have a minimum wattage or the lights will behave in a strange fashion. The electronic ones esp. are temp. to a minimum wattage-- some need to have at least 50% of the maximum wattage supplied by the trany to be utilized.

Maybe someone changed the bulbs to smaller wattages.

 

[domelectric]

Not LV. Straight 120V lights. Checked that first.

 

[BackInTheHabit]

Have you checked the tabs on the heads?

Take the heads that are not working and put them in a track that is working properly. If they do the same in a track that was originally working, you may have a bad track head.

 

[mdshunk]

Take the heads that are not working and put them in a track that is working properly. If they do the same in a track that was originally working, you may have a bad track head.

Thinking a neutral tab is contacting the 2nd ckt?

 

[domelectric]

All the lights work "properly" they just toggle inverse of one another.

 

[480sparky]

Is this a new problem, or did they always done this?

 

[domelectric]

If youre familiar with restaurant owners in Florida, everything worked fine yesterday and no other work was done on the ceiling, in the panel, or in the switch box. They all say the same thing. Everything worked fine yesterday...

 

[BackInTheHabit]

Thinking a neutral tab is contacting the 2nd ckt?

More or less. Sometimes the tabs don't make contact well enough.

 

[domelectric]

There's only one circuit with one dimmer and one switch leg leaving the switch box. There is a buried J box somewhere but it is impossible to tell where unless I rip apart plaster.

 

[480sparky]

More or less. Sometimes the tabs don't make contact well enough.

Sometimes they weren't installed correctly. I can't count the number of times I've tried to explain that track lighting has a polarity to it.

Half the track lights I've worked on over the years have the heads installed 180? incorrectly.

 

[480sparky]

There's only one circuit with one dimmer and one switch leg leaving the switch box. There is a buried J box somewhere but it is impossible to tell where unless I rip apart plaster.

An inaccessible box? Impossible!

 

[domelectric]

Forget about the heads. I disconnected the lights and checked with my DMM. 120 volts on two and zero on the third. Toggle the dimmer and I read zero at the two cables and 120 volts on the other.

 

[stickboy1375]

I hate to ask a dumb question, but did someone use a 3way dimmer in a single pole application?


Edit, never mind, thought i was on to something.

You need to find that j-box and see what the heck they did...

 

[domelectric]

I guess the only solution to this is convince the owner to fur down the ceiling an inch install new boxes and run a new cable straight to the switch box and be done with it. He's got the moolah anyway...

 

[BackInTheHabit]

Sometimes they weren't installed correctly. I can't count the number of times I've tried to explain that track lighting has a polarity to it.

Half the track lights I've worked on over the years have the heads installed 180? incorrectly.

Thank You!:grin: