How do I test the output of a T8 Ballast?

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  #1  
Old 01-08-08, 10:07 AM
K
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How do I test the output of a T8 Ballast?

Kitchen light won't come on. 120vac present at ballast input. How can I check the ballast output to verify that it is the ballast before I purchase another. Is there a particular voltage output I should read or do you take the ballast out of the circuit and jump around it? Or if there is another way to test it great. Thanks ahead of time.

One more thing that might help with this info is this. The ballast it use on a 4 lamp fixture and has 2 yellow, 2 red, and 2 blue output wires to the bulbs.
 
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Old 01-08-08, 11:36 PM
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IMO if this is a electronic ballast my best bet is get new ballast i won't even bother testing them for few reasons;,,

one,.. the open circuit voltage is much higher than the standard resdentail voltage is they are typically 300- 500 volts range depending on the manufacters design is.

secondally., it is pretty hard to use the standard test meter to read the voltage due very high HZ on electronic ballast and with some of the plain jane voltage tester may not work with very high HZ.

third thing .,, most electronic ballast must have good grounding soruce [ this is true for just about all flourscent luminaires expect some of CFL that diffrent story there ]

sometime it really justify just replace the whole luminaire [ if a cheap one ] due the cost of electronic ballast somehow little more than convental ballast is. [ majorty of the T-8's are useally are electronic ballast expect few specal sized some can run plain jane mangatic balllast.]

for cost of ballast i really cant say too much becase it will varies alot depending on where ya from and if get it from big box store or electrical supply centre etc etc .,,

and my final advise to ya if you really want to change the ballast you can but MAKE sure you follow the manufacter wireing connection very carefully.

Merci, Marc
 
  #3  
Old 01-09-08, 07:37 AM
J
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Simple. Put a new tube in. If it doesn't come on change the ballast.
 
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Old 01-09-08, 08:13 AM
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I agree with Joe. For virtually all problems with fluorescent fixtures, it's usually a good idea to start by replacing the bulbs. And always replace all the bulbs in the fixture at the same time--don't just replace one of them.

If replacing the bulbs doesn't do the trick, and if you have verified that the fixture is grounded, then it's sometimes easier and cheaper to replace the whole fixture than to replace the ballast.
 
  #5  
Old 01-09-08, 05:26 PM
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I went with replacing the ballast and all if fine now. Thanks for the input.
 
 

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