Troubleshooting LV Recessed Can

[AZsparky]

Anybody with a thought on this? Went on a service call today. Found three 4" recessed LV cans with magnetic ballasts installed by others. All three are controlled by 600 watt dimmer. Two cans work fine. Voltage reads 13.4 volts at no dim position at ceramic lamp holder (MR16 50 watt) on all three cans. Thought the lamp on the one can was possibly not making good contact with the ceramic lamp holder so even tried inserting temp leads out of lamp holder and trying lamp directly connected to leads. Nothing. I tested the leads and they had the 13.4v on them. The lamps tried are definitely good. They work in any of the other cans. It doesn't seem possible that this lamp won't light off of this transformer when the voltage is there. I just don't get it. What am I missing?

 

[480sparky]

Anybody with a thought on this? Went on a service call today. Found three 4" recessed LV cans with magnetic ballasts installed by others. All three are controlled by 600 watt dimmer. Two cans work fine. Voltage reads 13.4 volts at no dim position at ceramic lamp holder (MR16 50 watt) on all three cans. Thought the lamp on the one can was possibly not making good contact with the ceramic lamp holder so even tried inserting temp leads out of lamp holder and trying lamp directly connected to leads. Nothing. I tested the leads and they had the 13.4v on them. The lamps tried are definitely good. They work in any of the other cans. It doesn't seem possible that this lamp won't light off of this transformer when the voltage is there. I just don't get it. What am I missing?

Is the dimmer rated to dim a transformer?

 

[AZsparky]

Transformers rated as dimmable?

Transformers rated as dimmable?

Well I definitely should have, but didn't check. But, I do have acceptable voltage at the lamp socket, so it should light the lamp regardless, shouldn't it?

 

[stickboy1375]

In my experience the socket fails, replace the socket.

 

[JohnJ0906]

Next time, try it without the dimmer.

When troubleshooting, I like to eliminate each possibility 1 by 1. Dimmer, lamp, socket, etc. (In no particular order)

 

[480sparky]

Next time, try it without the dimmer. (In no particular order)

Or with the load (bulb) in place. If the voltage drops, it's not the bulb.

 

[480sparky]

Next time, try it without the dimmer. (In no particular order)

Or with the load (bulb) in place. If the voltage drops, it's not the bulb.

 

[AZsparky]

Hi John:
What i don't understand is if two cans work fine from the dimmer and I have correct voltage at all three why wouldn't the lamp fire up? That is the part I don't understand. How could the dimmer be the cause of this at only one fixture (they are all identical) and with the correct voltage present?

 

[stickboy1375]

Hi John:
What i don't understand is if two cans work fine from the dimmer and I have correct voltage at all three why wouldn't the lamp fire up? That is the part I don't understand. How could the dimmer be the cause of this at only one fixture (they are all identical) and with the correct voltage present?

This is why in i stated in my experence if one lamp out of a row of whatever is not working its either the lamp, socket or the transformer. But I find the socket to be the problem 9 out of 10 times, for some reason the sockets just dont hold up well.

 

[480sparky]

Hi John:
What i don't understand is if two cans work fine from the dimmer and I have correct voltage at all three why wouldn't the lamp fire up? That is the part I don't understand. How could the dimmer be the cause of this at only one fixture (they are all identical) and with the correct voltage present?

Is that the voltage under load? or with no load?

 

[AZsparky]

Thanks. I am not worthy

Thanks. I am not worthy

I think that it must be a bad xfmr. I did not test the socket under load (stupid). The transformer probably drops out under load and probably because they have it controlled either by the wrong type dimmer or the ballast is non-dimmable. I know they are Nicor cans. I probably need to make a phone call. OOPS!

 

[cadpoint]

Hi John:
What i don't understand is if two cans work fine from the dimmer and I have correct voltage at all three why wouldn't the lamp fire up? That is the part I don't understand. How could the dimmer be the cause of this at only one fixture (they are all identical) and with the correct voltage present?

Cause we can assume that everything working fine till the device!