120-277V 4 lamp T5 ballast

[Davebones]

Have ballast that was wired to a 120V circuit . I was told that it won't work now on a 277V circuit . Another electrician said that once you wire it on one voltage that's it . Don't usually mess with lighting so I'm not sure . Is this true ???

 

[Barndog]

Have ballast that was wired to a 120V circuit . I was told that it won't work now on a 277V circuit . Another electrician said that once you wire it on one voltage that's it . Don't usually mess with lighting so I'm not sure . Is this true ???

As long as its a Dual voltage ballst it should work on both voltages. I know the one's we use here do. But i have heard that those will not work on 208 just either 120 or 277 but dont know that for sure.

 

[TNBaer]

Have ballast that was wired to a 120V circuit . I was told that it won't work now on a 277V circuit . Another electrician said that once you wire it on one voltage that's it . Don't usually mess with lighting so I'm not sure . Is this true ???

I've been installing T5 for 6 years and I've never heard of this.

 

[hurk27]

Most ballast today are rated 120-277 which means they are voltage regulator controlled and will work any where in between and can be changed later to another voltage, but I have ran into a few 120/277 dual voltage ballast that once powered up on one voltage it blows open the internal feed to the other voltage, and can no longer be used on the other voltage, I haven't installed any dual voltage ballast lately so I have no idea if this is still holds true?

The difference is how they write the voltage - is all voltage between and / is either one or the other voltage (dual voltage)

 

[kwired]

Most ballast today are rated 120-277 which means they are voltage regulator controlled and will work any where in between and can be changed later to another voltage, but I have ran into a few 120/277 dual voltage ballast that once powered up on one voltage it blows open the internal feed to the other voltage, and can no longer be used on the other voltage, I haven't installed any dual voltage ballast lately so I have no idea if this is still holds true?

The difference is how they write the voltage - is all voltage between and / is either one or the other voltage (dual voltage)

With that logic it would seem that they will work connected to 120 volts and can later be connected to 277. But once connected to 277 they will no longer work at 120. This would confirm the myth that I have always heard, is that once connected to the higher voltage rating they will no longer work at the lower rating.

 

[Electric-Light]

It's certain possible for the front-end boost converter to fail overtime allowing it to remain functional and provide sufficient DC rail voltage on 277v, but not able to provide boost on 120v and fail to operate. Failed front-end should be obvious by measuring power factor. If its not registering >0.90 PF, it means the active PFC front end failed.

It's not like an older computers that used 115/230 switch to disable/enable voltage doubler (doubler used with 120v to get 340v DC bus, disabled on 240v to get 340v w/o doubler). If ballasts employed a fusible link or similar to make this switch, it will be stated in the instruction that once used on higher voltage, it can not be used again on lower voltage.