Hey guys I picked up a cheap 240v HPS 1000w light for cheap on craiglist. I know I can wire up a 220v outlet and it will work, but do you think a transformer would work. I see many for converting 110v > 220v. From 500w - 5000w. I know to "strike" the bulb and turn it on it requires around 4500v. Then once its lit up it drops down to 220v or 110v depending on the light you have.

 

On the face of it, a transformer should work OK, BUT methinks it would be more trouble than it's worth. If you have 220 volts available, that is a much cleaner way to use the device.

 

call up your local electrical supply house and quote a ballast kit. They all come with 110/277/347 taps.

 

Been there, done that. A transformer will work perfectly. Problem is that the 1000 watt transformer will be expensive. Compare prices to a proper ballast and ignitor for 1Kw@120VAC.

Another approch would be to use a lower wattage bulb. The current is controlled by an inductor. Half voltage = half current. You would have to look up specs on HPS bulbs to see which one will work at the current supplied by your ballast at the voltage you have from the power company. You can measure the real current by simply putting the inductor across the 120VAC line and measuring the current. If your fixtures are like mine, you can just take the bulb out and measure current at the light socket (with the ignitor disconnected). Do not run the bulbs at higher than the rated current. It makes them fail much quicker. I run mine about 9% low and get many years of service compared to allowing the power company to put 125 VAC (4% high) into them and have them fail in less than 3 years.

Any questions?

 

I figured I'd use a 1500w or 3000w transformer for each 1000w light if I needed. I've decided to just wire up 220v though since I don't think I'd get the power savings the 220v gives if I use a transformer.