Current surges knocking out LED drivers

[MTFEA]

An installation of LED lamps in refrigerated space (inside reach-in glass doors on grocery cooler) has seen high failure rate of LED lamp drivers (AC to DC). LED lamps are powered by a branch on the same phase (but separate branch circuit) as anti-sweat door heaters totalling 30A. Separate installation of controlls on door heater circuits have solid state relays opening and closing the 30A door heater circuits on a frequency of about 1HZ.

Could the voltage spike associated with each OFF cycle of the door heater circuits be causing the LED drivers to fail even though they are on a different branch circuit? e.g. the voltage spike would have to be traveling through the service panel and out the LED light branch to reach the drivers. It is a small store with not a lot on the panels (not a lot of other systems to damp out the voltage spike).

 

[zappedagain]

That's one possibility. You really need to get an oscilloscope and monitor the AC power at the LED driver and see if it is within the driver's specifications.

Is the driver mounted in the frig too? Is it specified to work at that temperature? Or is it sitting on top of the frig and maybe running too warm?

You might want to try plugging the LED drivers into a surge protector and see if that helps. Or an uninterruptable power supply (UPS) might help too.

 

[waross]

Heaters don't usually cause a voltage surge. Typically there will be a small voltage drop when the heater turns on and a return of the voltage when the heater turns off.This is often less than 1 volt.
However, low voltage wiring running parallel to high current wiring may have voltages induced in it.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

Might be more like the compressor turn-off doing it. It would be readily apparent with a scope job on the driver input.

If it is the door heaters then typical "surge suppressors" will not last long at all as they have a limit on the number of cycles they handle.

It could also be the fact that you are interrupting the driver power several hundred times a day if you're controlling them with door switches.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[geekEE]

Could condensation be getting onto the driver chip? It could make for a mysterious failure if it dries up before you are able to examine it.

Glenn

 

[MacGyverS2000]

My first angle of attack would be the compressors... those are nasty little buggers when it comes to spikes.

In what manner does the driver fail? Is the driver chip shorted at the output?

Dan - Owner

http://www.Hi-TecDesigns.com

 

[LionelHutz]

It's quite likely the heater controls are zero-crossing switches and they'd produce very little for transient noise. It could also be a poor design, moisture, heat or cold causing the problem.