120v MH wall pack

[lat1]

I am trouble shooting a RAB wall pack and am reading 277v H-N/G at the socket. Everything seems to be wired corectly. The fixture is rated for 120v. The new 150w lamp is not lighting.
Is 277v at the socket correct? If not, what is the culprit? Capacitor, ballast?

Thanks for the help.

 

[sameguy]

Off the top of my head you should have a high voltage pulse ~ 1kv from a starting cap. look there first.

 

[Cow]

If you have 120 at the socket and you've tried a new lamp, then it's time to put a ballast kit in it. It isn't worth the time to just replace the capacitor just to have the ballast go out a week later.

Advance has a troubleshooting guide on their site that'll give you open circuit voltage(socket voltage).

 

[kwired]

I think 150 watt MH is a pulse start lamp so this fixture should also have an ignitor, if you have voltage at socket ballast is most likely ok even though I don't know what voltage you should have.

Make sure you have the right lamp for the ballast. If customer tried to replace it first they may not even have correct lamp.

 

[480sparky]

.............Advance has a troubleshooting guide on their site that'll give you open circuit voltage(socket voltage).

It's gone. But you can Click here.

Start t-shooting on page 28/29.

 

[hillbilly1]

If it is a pulse start fixture, a regular MH lamp will screw in, but not make contact. PS lamps have a narrow tip at the end to get past the rejection feature on the socket.