120 vs. 240 volt on HPS ballast

[TheAcapolcoGold]

I am a new grower and decided to use a hydroponic set up. I have a 400 watt HPS bulb that I plan to use. I can not find out on the internet what the difference is between the 120 and 240 volt outputs on the ballast? Is there any way that I can decide which one I should be using?

Thanks

 

[Farmer Jon]

If you are wondering which to use?..120v vs. 240v the only difference is the amount of amps it will pull @ 240v it will use half as many amps. My guess is that it is set up for 120v seeing as it is only a 400w lamp but i guess that would depend on where you are located in the world.
Typically if it is 120v the plug on the end will look like any other plug you have around the house (2 flat prongs facing the same way and 1 round prong)
you can plug a 120v cord into any household eletrical socket but a 240v plug will need to be hooked into a special socket.(it will also typically look different)
240v is generally used when you are concerned with the amount of amperage available.

 

[convex]

Unless you have a switchable ballast, you would have to open your ballast and manually switch the voltage tap from the 120 to the 240 line.

Any commercial ballast (North America) should have a rating plate/sticker stating the assembled voltage.

Cheers

 

[blahman]

I run all my 1000w's at 240v. First like the others have said they use half the amps. Second with them using half the amps you can have more lights.