Anyone know how to test the output power of a MH ballast?

[Southern Boy]

I picked up a 150 hqi pendent and the ballast is on but the bulb won't fire.Is ther a setting on a multi meter that can tell me if I'm getting the proper amount of current?

[DOTZ]

Yeah volts AC is home use. Set it to 120 volt and you should be good to go.

[PaulErik]

You can’t use a multi meter to test the output of a HQI ballast. The ballasts output voltage exceeds multi meter voltage ratings. It will fry/damage a multi meter.

If the ballast makes a buzzing/humming sound then the ballast is working. Reseat the bulb and make sure the bulb is making proper contact with the socket/s. Does the bulb glow at all? Sometimes the bulb will glow dimly with a poor connection.

[DOTZ]

You can hook a multi meter up to it. It will not exceed it. I check alot of wiring on fuse boxes and out of the wall. You will get 120 in or so and you should be able to check the ends of the wires. for voltage.

[Southern Boy]

Nope,it's not glowing at all.The bulb is almost brand new.Maybe a days worth of use.I tryed my meter on it before I asked and fot 400 or so volts.I thought that was kinda funny.But I did get the same voltage before and after the wire.Hummm...

[PaulErik]

You can test it before the ballast but not the ballast output. An ANSI M81 (HQI) ballast will output a high voltage pulse up to 6000 volts on the Open Circuit Voltage (OCV).

[PaulErik]

Is the ballast magnetic or electronic? Does the ballast or fixture buzz (a high pitch sound). If it is a magnetic ballast the high voltage lamp ignitor/starter will be with the ballast or inside the light fixture. If you test the ballast output you must disconnect the ignitor. If the ballast is magnetic and you hear a high pitch buzz this indicates the ignitor is working and the ballast is providing power.

[Southern Boy]

It has a igniter.The ballast is making a light humb but the ignighter has yet to make a peep!

[PaulErik]

Does the ballast and/or ignitor buzz when powered on?

You can test the output voltage as long as you disconnect the ignitor. The proper way to disconnect an ignitor for testing is to disconnect the common / white wire and cap it off. ANSI specifies the voltage should be between 220 to 260 volts AC without an ignitor for an ANSI M81 (HQI) ballast.

[PaulErik]

If you don't hear a high pitch buzz this indicates the ignitor is not working. You can replace it but you must get one that matches the old one. Best way is to contact the manufacturer of the light fixture. They usually have spare parts.

[Southern Boy]

Yea I kinda thought that was the problem when I didn't here it giving that annoying buzz that all my others have made when I 1st turned it on.This is my 1st hqi though so I wasn't sure.Thanks for the input.Can the ignighter be bypassed just to see if the rest works?

[PaulErik]

The only thing you could do is disconnect the ignitor and perform a voltage test on the ballast. If the voltage output of the ballast is between 220 to 260 volts AC the rest should be working fine.