HID High-Bay Lights Randomly Going Out

[Dumbo2929]

Here is a good one. A large warehouse had high bay 400W MH lights that randomly go out, either one row, a few fixtures, or the whole place. The problem is they take 15 minutes to cool down and restrike. None of the fluorescent lights go out, or any other equipment. There is lots of motor load (roof top units, refrigeration motors), most of which is 208V. The lighting is all single-phase 277V. I'm thinking harmonics and will do some metering to confirm. Voltage recording shows proper line voltage from the utility.

The next question, is does anyone know vendors in the US of small harmonics filters, that I can put on the 200A, 480/277V lighting panel, or even small for individual 277V lighting 20A circuits?

 

[dbaird]

Check:

http://www.mtecorp.com/

David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[gepman]

I would be surprised if it was a harmonics issue. I have operated CWA MH HID ballasts in facilities where VFD's were over 60% of the load. My guess is that you are getting some voltage drop when your 208V motor load is starting or some other cause of voltage drop which drops out the lights.

(Why do you have 208V motors and 277V lighing? It would seem you would want to have 480V motors and in any case the motors do not create any harmonics unless they are VFD run.)

You can also see

http://www.advancetransformer.com/uploads/resources/hid-troubleshooting-guide.pdf

for troubleshooting information.

 

[dpc]

Just fyi, it is possible to fit most MH luminaires with a quartz lamp to help provide some light while waiting for the MH lamps to cool down. This would only have to be done on a few fixtures.

Like gepman, my first thought would be low voltage causing these to drop out. How old are the ballasts?

 

[gepman]

Since dpc mentioned auxiliary quartz lamps there is another product that I have seen by Bodine which is called "Arc Keeper". I haven't used them but I have thought about using them the next time that I design a facility with HID lamps that has a backup generator for emergency lighting that I would use them. It keeps the arc going for up to a couple of minutes during a power outage so you have time to switch the backup generator on without losing your lights.

See

http://www.bodine.com/products/arc.html

 

[Dumbo2929]

Thanks for the help. Some of the ballasts are new, and some are as old as 10 years. I have no idea why most of the motor load is 208V, not 480V. It is possible the whole service was originally 208V.

I've attached the voltage recording data, and the voltage looks good. The ballast manufacturer says a 13% drop is needed, or about 240V on a 277V system. The voltage seems fine.

 

[itsmoked]

Since I've run a 175W MH in my living room for 14 years I can attest to the fact that the tiniest power glitch will extinguish a HID. It happens all the time. Sometimes you can notice the power glitch if it's substantial enough in other things. But sometimes the only the HID and a high end UPS notice. I have no other indicator. The arc in the HID needs just a part(the right part) of a powerline cycle to be missing to do the deed.

I agree gepman, harmonics? Nope!

208V is lousy for motor starting in my experience, especially refrigeration. You can get lots of dips from that.

One thought would be to check out new vastly more efficient solid state ballasts as they will save you operating costs, and can run the HIDs with better lumen retention, longer, and can allow for much faster restrike. But more importantly, since they are sort of like a switching power supply they may 'carry over' glitches.

I can see SState HID ballasts paying dividends. Maybe some energy credits too? ??

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Dumbo2929]

I'm going to hook up my RPM power quality analyzer and should be able to capture any sub-cycle voltage dips. Thanks to everyone for their input.

 

[itsmoked]

Let us know what you find.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[gepman]

The time scale on your recording is too large (perhaps small, I always get it mixed up) to see if you have any momentary drops in voltage. Make certain that you monitor the branch circuit or at least the panelboard voltage, not the service voltage.

If you are going to replace ballasts or fixtures you probably should think of going to 4 or 6 lamp T5HO fixtures. In California you would get a $75 rebate per fixture for the 6 lamp unit replacing a 400W MH or a $100 rebate per fixture for a 4 lamp unit replacing a 400W MH. If you put an on fixture occupancy sensor then you can get another $20 rebate per fixture and they are only on in your warehouse when someone is underneath them. It will save at least 120W per fixture while they are on (over the 458W MH ballast) and 458W while they are off with basically the same amount of light. They are the standard design in warehouses these days. About the only disadvantage is that they have more lamps to relamp.

 

[itsmoked]

You'd really want to see a display of something on the order of 10-20ms/division.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Dumbo2929]

The RPM 1650 can sample down to 128 samples per cycle, so it will capture any voltage dips

 

[itsmoked]

That will be fast enough! But unless it is a triggered short time snap shot recorder I can't imagine it recording for very long at all.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com