Blinking light troubleshooting 101

[dhalleron]

Any suggestions on how to troubleshoot a problem that is never happening when I am there? I don?t do a lot of troubleshooting.

This is an old house wired in BX with solder and taped joints. The kitchen has been remodeled and some can lights added downstream of this light by some jack leg. I fixed some of his connections that were questionable.

Customer says no other lights blink. This one can be on all day and no problem. She says when it blinks; it?s like someone turns the switch off and on rapidly for a long time and it is all of the bulbs not just one or two.

She has a 9 light chandelier over the dining room table on a dimmer. It originally had 9 60 watt candelabra bulbs on a 600 watt dimmer. She changed the bulbs to 40 watts and I replaced the dimmer.

This is the first light from the breaker panel on a multi-wire circuit. Both circuits continue on from the light box and one switch leg goes down to the dimmer.

I checked ALL connections in the panel and they are tight. I found one solder joint in the light box that was loose so I broke all the joints in the light box and made new joints. I checked the sockets of all the bulbs for dirt and bent the tabs back out so they might make better contact. I took the fixture junction box cap off the bottom of the light and made sure all the joints going to the individual lamp holders were tight.

I have been there 3 times and spent at least an hour each time and never saw it blink. I'm tired of going back. I might just run all new wire to the light and switch next time.

 

[jumper]

Did the light blink before you replaced the dimmer?

 

[dhalleron]

Did the light blink before you replaced the dimmer?

She said it did before and after. I have never seen it blink. She has 2 other witnesses that play cards at that table who say it blinks sometimes.

 

[jumper]

The worst problem is dealing with customer supplied info.

It would be nice to know if you were sure no other lights blink on that circuit, but you can only do what you can do.

I would not bother with a new supply if the customer is correct, I think I would focus on the switch leg. Buried box/splice perhaps?

 

[dhalleron]

Buried box/splice perhaps?

There was a buried box in the attic insulation. The original bx switch leg was put into a JB and then switched over to romex to go down the wall to the switch for some reason. I checked the joints in the JB.

And yes customer supplied info is not always the best. Wish I could see it blink.

 

[weressl]

Any suggestions on how to troubleshoot a problem that is never happening when I am there? I don?t do a lot of troubleshooting.

This is an old house wired in BX with solder and taped joints. The kitchen has been remodeled and some can lights added downstream of this light by some jack leg. I fixed some of his connections that were questionable.

Customer says no other lights blink. This one can be on all day and no problem. She says when it blinks; it?s like someone turns the switch off and on rapidly for a long time and it is all of the bulbs not just one or two.

She has a 9 light chandelier over the dining room table on a dimmer. It originally had 9 60 watt candelabra bulbs on a 600 watt dimmer. She changed the bulbs to 40 watts and I replaced the dimmer.

This is the first light from the breaker panel on a multi-wire circuit. Both circuits continue on from the light box and one switch leg goes down to the dimmer.

I checked ALL connections in the panel and they are tight. I found one solder joint in the light box that was loose so I broke all the joints in the light box and made new joints. I checked the sockets of all the bulbs for dirt and bent the tabs back out so they might make better contact. I took the fixture junction box cap off the bottom of the light and made sure all the joints going to the individual lamp holders were tight.

I have been there 3 times and spent at least an hour each time and never saw it blink. I'm tired of going back. I might just run all new wire to the light and switch next time.

Step one:

• bypass blinker

 

[dhalleron]

Step one:

• bypass blinker

I should have known to check to see if it was wired into the Christmas tree lighting circuit... I did look for the blinker but I couldn?t find the blinking thing.

 

[gndrod]

blink...

blink...

By any chance, would the lighting BC have the refrig hooked to it?

 

[mivey]

If no other lights blink, including the cans that are downstream, here are a few ideas:

1) Bad fixture wire (have found bad splices in down tube before): remove fixture and meg it, re-wire it, or hang temporary light to see if it blinks (Preferably a BIG light).

2) Hidden bad splice in switch leg

3) Pinched wire shorting to box (device or clamp).

4) You missed fixing a bad joint at the fixture box.

5) The down-line cans really do blink and they are not really paying that close of attention during the game (did you pull the breaker and check the bus?).

 

[480sparky]

Can light?....... thermal cut-out.

 

[mivey]

Can light?....... thermal cut-out.

Supposedly not blinking.

Customer says no other lights blink...a 9 light chandelier...

 

[480sparky]

Maybe a loose connection in the light itself. A chandelier with 9 lamps will have somewhere in it that has two splices in it..... with 10 wires in each splice.

 

[mivey]

Maybe a loose connection in the light itself. A chandelier with 9 lamps will have somewhere in it that has two splices in it..... with 10 wires in each splice.

And a 74B.:grin:

 

[dhalleron]

This one has still got me stumped.

This one has still got me stumped.

I've been back about 4 times. They weren't all wasted trips because I did some other work too.

It has never blinked when I was there. She does have a witness that happens to be someone I?ve known for nearly 20 years and I trust him on this. The other lights on that same circuit never blink per the witness.

It's not the chandelier. She bought a new one that I installed.

I replaced the switch leg.

The panel is in a finished basement or I would have just ran a whole new circuit for this. It is the first light on the circuit. Everything downstream seems to work, so I don't think it's the feed or the breaker.

I replaced the dimmer twice. After I left this last time, I got to thinking about the dimmer. I had to break some of the tabs off because this is a double gang box with two dimmers. I should have replaced it with a regular switch and see if that helps.

What are the symptoms of an overheating dimmer? If the missing tabs de-rated the dimmer would it cause the light to blink if there were 540 incandescent watts on a 600 watt dimmer?

I'm going back with a data logging meter I bought after reading another post on here about using one. I'll maybe check the voltage over time at the breaker and at the feed in the light to make sure the power is ok coming in.

 

[dhalleron]

OK. So I broke down and read the instruction sheet for the dimmer. It says it de-rates to 500 watts with one side removed.

She has 540 watts on the dimmer. But she said she always had nine 60 watt bulbs in the fixture and it always worked before. This is where I was supposed to not believe the customer. The old dimmer has one side removed also, so it was de-rated.

So now I need to see it a 1000 watt dimmer will fit in this 2 gang box. Or see if she can deal with 40 watt bulbs. I still might try just a single pole switch to see if that fixes it before I replace it with a more expensive dimmer.

 

[gar]

110130-2145 EST

dhalleron:

If I understand your description then you have the following:

1. A circuit fed from a main panel breaker.

2. On this circuit there is a dimmer feeding a light fixture with many bulbs and these lights flicker at times. Apparently only the lights on the dimmer flicker.

3 On this same circuit there are other lights further down stream that do not flicker.

4. None of this has been seen by you.

5. Is it correct to assume that the dimmer and flickering lights are equivalent to a tap midway along the circuit?

6. Have you measured supply voltage?

7. I would put a min-max meter on the circuit at a point beyond where the flickering lights are tapped into the circuit.

8. Connect your recording meter (data logger) across the flickering light fixture. In other words after the dimmer.

9. See what the results are.

10. I would not put a 500 W incandescent load on a 600 W dimmer.

11. Ask the observers how fast the light flickers. On time and off time? What is the dimmer setting when this occurs. Maximum brightness will cause the maximum power dissipation in the dimmer. More heat sinking of the dimmer will reduce its temperature rise at a given load current.

12. If there is not a large voltage change on the circuit, but there is at the fixture, then this pretty much isolates the problem area.

.

 

[hurk27]

I had a Leviton 600 watt dimmer once that would strobe the lights if you got any where near the rated capacity, we changed them out to another brand and never had a problem, we had 13 40 watt lamps on one, and after a while it would start strobing, but only when dimmed to about 60% and after it heated up which took almost an hour.

 

[LarryFine]

Suggestion: Temporarily wire two small lights in some way, such as split the hot side of a duplex receptacle, plug in two nightlights, attach three wires to the receptacle.

Now, drop the canopy, attach the receptacle's neutral wire to the ceiling-box's neutral, one hot to the always-hot line in the box, and the other to the switch-leg's return hot.

Then, tell them to note whether both, one, or neither of the nightlights blink with the fixture next time it happens. That will tell you where the intermittent connection is.

 

[ptonsparky]

Suggestion: Temporarily wire two small lights in some way, such as split the hot side of a duplex receptacle, plug in two nightlights, attach three wires to the receptacle.

Now, drop the canopy, attach the receptacle's neutral wire to the ceiling-box's neutral, one hot to the always-hot line in the box, and the other to the switch-leg's return hot.

Then, tell them to note whether both, one, or neither of the nightlights blink with the fixture next time it happens. That will tell you where the intermittent connection is.

This is not a good idea. How in the world are you going to justify getting a new PQ meter if you use such a simple procedure?!

 

[Dennis Alwon]

Lutron dimmers are rated at 100% unless ganged with other dimmers.