284 volts???

[pmguy]

There are 50 hanging fixtures all 277-volt with 200watt incandescent lamps (there is a large acrylic diffuser with a porcelain lamp holder - like a low bay fixture retrofitted with a lamp holder and incandescent lamp). The new lamps started burning out at a pretty rapid pace. I checked voltage at the fixture and got 284 volts. I check at the breaker and got 284 volts. I check at the line side coming in from the utility service and got 284 volts. I called the manufacturer of the lamp and they confirmed that anything over 277 volts would cause the lamp to overheat and ultimately malfunction. Is it possible that the utility company is supplying too much voltage from the transformer? Is is pretty common for the voltage to be that much higher than what it is supposed to be? Is there any solution? Im confused....

 

[iwire]

284 is not unusual and well within the typical utility requirements.

You can see the service voltage could be almost 291 volts.

You might consider putting in a buck transformer or two to drop the voltage.

 

[Sierrasparky]

I would contact the POCO and see if they could adjust the transformer taps. It could be that they are set a bit High due to an anticipated higher load.

 

[pmguy]

Thank you. What about changing the lamp out to a 277 volt rated fluorescent? I found a medium base, 80 watt compact fluorescent lamp that was rated at 277 volts. About three time the cost of the incandescent lamp (about $31.00) each but I am guessing they wouldn't produce nearly as much heat and probably could handle the slight increase in voltage much better than the incandescent. I am worried that the heat from the incandescent lamps would be a fire hazard (they were so hot it started to melt the metal threads on the lamp). Do you think the fluorescent lamps would be a simple (yet costly) solution?

 

[pmguy]

Would a fluorescent lamp handle the higher voltage and heat better? I found a 80 watt / medium base / 277-volt rated lamp (a bit pricy at $31.00 each) that I can use. I am mainly worried about the incandescent lamps getting so hot and burning up. It may be a fire hazard.

 

[weressl]

Thank you. What about changing the lamp out to a 277 volt rated fluorescent? I found a medium base, 80 watt compact fluorescent lamp that was rated at 277 volts. About three time the cost of the incandescent lamp (about $31.00) each but I am guessing they wouldn't produce nearly as much heat and probably could handle the slight increase in voltage much better than the incandescent. I am worried that the heat from the incandescent lamps would be a fire hazard (they were so hot it started to melt the metal threads on the lamp). Do you think the fluorescent lamps would be a simple (yet costly) solution?

http://cgi.ebay.com/42W-SPRINGLAMP-...069?pt=LH_DefaultDomain_0&hash=item230d8e5135

42W and it's output is about equivalent of the Phillips 200W incandescent. About $18.50/ea.

 

[Electric-Light]

Not sure about CFLs, but all name brand external ballast specifications allow continuous operation at +/- 10%, so 305v max. Many newer ballasts are auto-compensating. They will back off on current as voltage increases and raise the current on voltage drops.

Incandescent lamps are sensitive to voltage. 5% increase = 1/2 life. 10% = 1/4. We have 130v bulbs, because many homes have 123-126v on regular basis.

You can install a dimmer and dim it just a tad bit at the expense of efficacy.