Bizarre Dimming Situation

[360Youth]

I did a service call the other for a shorted circuit and the HO asked me to look so recessed lights they were having problems with. When the lights are on full, everything is fine. When you dim the lights you get this...

One light stays full while the others dim down. It actually does this on two sets of lights. One set of 2 and one set of 6. I left one job in the middle to handle the emergency of a shorted circuit, so I did not have time to stay and investigate any further. The HO is a regular customer so I said we would be back to look at it. Anyone seen this before? I have some theories, but none that add up to much on surface value.

 

[mdshunk]

Somebody changed something. That didn't fail that way. Your task is to figure out what somebody recently touched.

 

[electricalperson]

I did a service call the other for a shorted circuit and the HO asked me to look so recessed lights they were having problems with. When the lights are on full, everything is fine. When you dim the lights you get this...

One light stays full while the others dim down. It actually does this on two sets of lights. One set of 2 and one set of 6. I left one job in the middle to handle the emergency of a shorted circuit, so I did not have time to stay and investigate any further. The HO is a regular customer so I said we would be back to look at it. Anyone seen this before? I have some theories, but none that add up to much on surface value.

are the lamps effected anyway even slight dimming or do they stay at 100% full brilliance?

 

[360Youth]

Somebody changed something.

Way to throw yourself into that one. Let the knowledge shine. :grin: :grin: I understand what you are getting at, but man, the wording of that one almost put me on the floor. :smile: Actually, I thought you might one of the first to respond because I think of most anybody here, you have seen it all.

 

[360Youth]

are the lamps effected anyway even slight dimming or do they stay at 100% full brilliance?

I believe the stay on until the very end and then they just go out.

 

[Ed Carr]

360..is there a 3 way switch in the mix with maybe a dimmer at each end?

 

[480sparky]

Are you sure they're incandescent bulbs and not CFLs?

 

[electricalperson]

i wonder if a loose connection in those lights could be causing that problem.

the way i would start to troubleshoot this is checking connections in the boxes and in the light fixtures

 

[360Youth]

360..is there a 3 way switch in the mix with maybe a dimmer at each end?

I had to get back to the job I was in the middle of when the emergency call came in. I do not know much more than what the pics show at this point. The dimmers were the rotary type, so no clear indication to single pole or 3-way.

My first step is to change the dimmers. They were a little sporatic in their function so I think that is a must. I don't see that explaining the fact that one of the lights seems to maintain full voltage unless for some reason the original EC pulled a separate switch leg, isolated from the rest of the lights. I am open to what you think. Thanks.

 

[mdshunk]

My first step is to change the dimmers. They were a little sporatic in their function so I think that is a must.

With that extra information, I echo 480's thoughts. Make sure these aren't CFL's. The new dimming CFL's suck. They make the dimmer seem sporadic, and only "sorta dim". Like I say, somebody did something, and that something might be the substitution of CFL's.

 

[Ed Carr]

It does have some of the appearance of a neutral problem.
Also I meant two 3way dimmers in the circuit.
I know what Marc is getting at. Look for the last ham fisted
thing that was done there by someone else!

 

[360Youth]

With that extra information, I echo 480's thoughts. Make sure these aren't CFL's. The new dimming CFL's suck. They make the dimmer seem sporadic, and only "sorta dim". Like I say, somebody did something, and that something might be the substitution of CFL's.

I'm assuming CFLs are compact fluorescents. Did not think to check. Thanks.

 

[electricalperson]

if CFL's are the problem ill add this thread to the reasons why i hate CFL's list

 

[480sparky]

I'm assuming CFLs are compact fluorescents. Did not think to check. Thanks.

Yes. CFLs will attempt to maintain lumen output as the dimmer is turned down, then it will suddenly go out or dim very low.

 

[Ed Carr]

I've said it before & I'll say it again...
Yer good 480 :grin:

 

[mdshunk]

Yes. CFLs will attempt to maintain lumen output as the dimmer is turned down, then it will suddenly go out or dim very low.

Even the new "dimmable" CFL R-lamps act sorta the same way. They dim sorta in "steps", then they just go really dim or off. Not linear at all. I had a customer supply some a few weeks ago for their new cans. When they saw how they acted, they all came out and got returned. I had some nice halogens along to use for the job anyhow.

 

[360Youth]

Yes. CFLs will attempt to maintain lumen output as the dimmer is turned down, then it will suddenly go out or dim very low.

Even the new "dimmable" CFL R-lamps act sorta the same way. They dim sorta in "steps", then they just go really dim or off.

When I grow up and have 4k and 8k posts, I wanna be just like you guys. :smile: Thanks. I knew somebody had to have seen similar situations before. Next time I will try and and include all relevant info on the first post.

 

[ohm]

Just in case the CFL idea doesn't pan out...are the lights fed by a multiwire branch circuit. If the loads are the same no current in the neutral, otherwise current divides etc.

 

[LarryFine]

I don't see that explaining the fact that one of the lights seems to maintain full voltage unless for some reason the original EC pulled a separate switch leg, isolated from the rest of the lights.

That's what I think, but then the dimmer would have absolutely no effect, on-off or anything, on the full-brilliance lights. In other words, this couldn't happen:

I believe the stay on until the very end and then they just go out.

This sounds more like the behavior of a non-dimmable light on a dimmer.

 

[220/221]

I have seen that orange glow before.


Something in my mental archives is suggesting that you check for some series miswiring.