Testing A Ballast

[SkiFletch]

So my nice new 192w T5 fixture arrived with two nicely broken bulbs and while I'm waiting for replacements I was wondering if there was any way I can check that the ballast is OK. I know that without fixtures plugged into them, turning on a ballast will not generate significant voltage at the pins. Can I put a resistor across the pins to simulate a bulb and then measure voltage, or would that damage the ballast? I have access to lots of electronic testing equipment: voltmeters, ammeters, oscilliscopes, variable load sources, etc, just need to know whats safe to do to a ballast

TIA

 

[drag]

i have alot of experiance in the electrical field, so i can tell you ballasts are very delicate. i would not put any resistors or any thing across the sockets. you could burn it up(it dont take much). and there not so cheap to be burning like that.



the only sure way to check it is with a lamp.
if you really want to have something to go by... you could use a proximity voltage tester. these only tell you if there is voltage present. you can get them at home depot or equivalent store. around here there like 10 bucks for a cheapo. i dont know if you ever heard of one they call them tick tracers, or hot sticks. they sense the magnetic sinewave. the higher the voltage the farther away from the hot wire the tester will light up.the good thing about these testers you dont have to get in to the circuit. stay safe, leave the electrical work to the pros. just a word of advice. ive seen what it can do.

 

[SkiFletch]

Amen to that drag, electrical stuff can be very dangerous. While I'm no electrical engineer, I have worked extensively with basic electrical circuitry as a research technician in a lab where building our own equipment is almoast required. I'm working on a system running off lithium polymer batteries which have a capacity across the 192 cells in the multiple kilowatt hour range so I'm versed with electrical safety . I say that to point out that I know enough to know when I'm in over my head.

I've never heard of a "proximity voltage tester" though. Are these variations on hall effect transformers? If so that makes some good sense. What kind of values should I expect from a "working" ballast designed for 2x96watt T5 bulbs?

 

[Aquascaper]

Well seeing as you know what you're talking about Drag could you perhaps shed any light on the issues i'm having with my Halide?

Link

 

[crazyelece]

All a proximity voltage tester does is light up and beep if there is voltage next to it. It won't do you much good. Its a tool for electricians so they know if the circuit they are working on is hot before they touch it. I know of no way to test a ballast (without the risk of destroying it) without a lamp.

 

[SkiFletch]

Thanks for the advice guys, I'll jsut have to wait all of 2 days for the replacement bulbs

 

[drag]

All a proximity voltage tester does is light up and beep if there is voltage next to it. It won't do you much good. Its a tool for electricians so they know if the circuit they are working on is hot before they touch it. I know of no way to test a ballast (without the risk of destroying it) without a lamp.

correct, like i said it test to see if voltage is present. ballast without output voltage is a bad ballast . but like i said thats if you want something to go by. that is only one sighn of a bad ballast. may or may not be the case.... probability is, it is not. but ist the only way you can safely check it without a lamp.

I am an electrician and use this method to give me some idea of whats going on. (when theres no lamp to check it with).

 

[crazyelece]

You have to be careful when powering up a ballast with no lamp, in some cases this can destroy the ballast. It just depends what type of ballast. If you don't specifically know what to do or what will happen, it is better to not do anything.