Emergency Power Generator damaging Electronic Ballasts ?

[Shray]

At my facility I have roof top substations and which some of them I have emergency back up nat gas generators. The generators provide power to 277 Volt Metal Halide Lighting for the production floor and also 277 v flourescent T8 lights with electronic ballasts in the rooftop substation itself. When recently testing the generator and transfer switch per NFPA requirements, I noticed that after the generator was running for 10+ minutes the flourescent lights started oscilating in light output the more and more the generator was left on. 50% of the lights ended up dying, since then I found out the bulbs and fuses are still good but the electronic ballasts are evidently fried. I am thinking of testing it again and perhaps putting a Fluke Power Quality analyzer on the generator output to see what is going on. The analog meter on the generator and a Fluke digital meter showed a solid 277 volts output while the generator was running. Does anyone have any suggestions as to what is going on here ?

 

[tg103]

Did you happen to check the frequency output of the generator?

 

[ruggedscot]

Check your harmonics....

what loads are running at site ?

rugged

 

[RRaghunath]

May be you should have a close look at the generator AVR and see that the same is in Auto.

It will help if you can keep voltage little lower (should pose no problem provided the load is mostly lighting).

How about harmonic filters in the system, are they available / working (electronic filtesr introduce harmonics in power supplies that can cause difficulties especially when the system is not connected to the grid).

 

[rob46]

http://www.healthcareengineering.net/62.htm

 

[BrianR]

What is your load power factor? With older equipment, I have seen some voltage regulators start pumping with switching regulator loads. The switchers vary their power factor as they regulate and the voltage regulator O/p varies and the switches changes power factor again in a vicious cycle.