Follow the manufacturer’s recommendations to a T!
Or consult a professional electrician for advice.
Consulting a non electrical forum for electrical advice is dangerous and could cause big set backs for you or even a fire could be caused from bad advice.

sharl said:

Hi all. Wondering if anyone could answer this:
If I have a fluence led ballast that is 120-277v with a 240v plug end, can I convert the plug end into 120v. New spot with breakers not wired for 240 yet. Thanks very much

Click to expand...

It could be internally wired for 240V, so changing the plug won't work and will likely result in a hell of a show!

B²

sharl said:

Hi all. Wondering if anyone could answer this:
If I have a fluence led ballast that is 120-277v with a 240v plug end, can I convert the plug end into 120v. New spot with breakers not wired for 240 yet. Thanks very much

Click to expand...

Yeah if it's 120v to 277v either 120v or 240v inputs will work. I wouldn't modify the cord but you can unplug the 240v cord from the ballast and use a 120v one for sure.

Does the 240v cord unplug from the ballast like a computer power cord or is it hardwired? If it's hardwired might be out of luck. Can you post a pic?

Edit: Both cords should be rated 300v, and the gauge will tell you the amperage, 120v over 240v is double the amps so check the guage of the wire and consult the electrical code to make sure. If it's like 100w it's 1 amp so the average computer cord would work 14 guage is good up to (12 amps) but for a ballast load wouldnt go more than 8 or 10 even though my 1000w hps ballast comes with a 14 guage 120v cord and pulls i think 8-9 amps. A full circuit of of 15 Amp 12 for 80% is really meant for a resistive load so technically u can run 1000w but..... that's pushing it and might get hot so if it's 500w or less you are good. If you're going to do it hold the cord where it plugs in the wall after it's been on there should be no heat at all.