240v Ballast on 120v Wall Outlet?

Old 12-11-17, 10:33 PM
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240v Ballast on 120v Wall Outlet?

Hi All,

I'm hoping someone can help me. I'm wanting to grow some fruits and veggies indoors so I sourced a grow light from Craigslist. I bought a 600Watt HID light which requires a ballast. On the ballast it says 240v for the plug. The guy who sold it to me says that he used it on a standard 120v wall outlet for over a year with no problems and the plug that came with the ballast is the standard 3 prong plug. Here is a picture of the ballast:


Here is a picture of the plug:

I know nothing about electricity and I'm scared of electricity. I've researched as much as possible but I can't get a straight answer from google. Can anyone tell me if it is safe to plug this ballast into a standard 120v plug?

Old 12-11-17, 10:47 PM
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Welcome to the forums.

Can't find anything on that company.

It says on it dual ballast and 240v. It's possible the ballasts are actually multi tap and someone changed them to run on 120v. I have a feeling since it's a dual ballast model..... they may actually be 120v ballasts that are now wired in parallel whereas originally they were wired in series.

These are all guesses. Without opening it up.... can't be more precise. If it works on 120v it would have to been wired to work that way because if it could only run on 240v and you plugged it into 120v.... the lamp(s) would probably not arc.
Old 12-12-17, 05:15 AM
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The best way to know is to plug it in and see if the light works. Since the ballast is old I assume the bulb is also old and might need replacing. If it doesn't light you've got your answer.

Personally I would go with LED. Most have switched to LED so metal halide and high pressure sodium can be had really cheap. The trade off are their high heat output and energy consumption. Also LED's can produce almost all of their light in the bands that plants need to grow so more of the light is being used by the plant where much of the spectrum produced by HID lights are wasted. Brand name LED lights can get expensive but there are numerous Chinese imports that work very well and are quite inexpensive.

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