Ballast

[jcole]

Went on a service call today to fix flour. light. Changed ballast from magnetic to electronic. The bulbs were F40 T12 and the ballast was listed for F40 bulbs. When I turn the switch on, the bulbs get red on the ends (about 1 to 2 seconds) before they come on. Also there is a hum from the ballast that really isnt loud but noticable. I thought with an eletronic ballast that there would be no hum. The ballast are rapid start so I know there should be a small delay but is this to much? What about the red glow? Did I do something wrong or am I worrying about nothing? Thanks for replies.

 

[raider1]

Was the electronic ballast designed to use T-12 tubes?

Most of the electronic ballasts that I have installed will only work with T-8 tubes not T-12.

Chris

 

[Jeff Weissman Electric]

Just gotta ask... you did change the bulbs to T-8's...Right?

 

[Polarcat]

you also need to change the tumbstones. and be sure you use the right ones
shunted, rapid, etc...

Joe
Member of (Deleted)

 

[stickboy1375]

I've seen plenty of ballast support both t12 and t8, my only question is this, after you replaced the ballast, did you install NEW t12 bulbs? because they sound like they were shot as well, I never do a ballast change without relamping as well...

 

[Dennis Alwon]

you also need to change the tumbstones. and be sure you use the right ones
shunted, rapid, etc...
Joe

By tombstones I assume you mean sockets--- why would you have to change them. I never have and never had a problem.

 

[stickboy1375]

you also need to change the tumbstones. and be sure you use the right ones
shunted, rapid, etc...
Joe

By tombstones I assume you mean sockets--- why would you have to change them. I never have and never had a problem.

I was wondering the same thing...

 

[iwire]

I assume you mean sockets--- why would you have to change them. I never have and never had a problem.

You have been lucky.

Sometimes the fixture will have the wrong sockets.

Take a look at PDF about this issue.

 

[Davids1964]

I know this may be a dumb question but did you rewire the light fix for the new ballast. I learned that on my first day in a new building after leaving and older building for 15 yrs. I replaced a older fixture with a new style ballast and I had to rewire the light.

 

[Polarcat]

I know this may be a dumb question but did you rewire the light fix for the new ballast. I learned that on my first day in a new building after leaving and older building for 15 yrs. I replaced a older fixture with a new style ballast and I had to rewire the light.

????????????

and as far a the sockets, we call them "tombstones" in NY. Sorry for the slang. and belive me we have a lot in NY. like "Jem boxes", "1900 box", etc...

if you have never had to change a "tombstone/socket" you have been extremly lucky. I am a comercial contractor and dont do a lot of renovations, and I have had to change a lot of them over the years. guess I am unlucky or I got your share of them plus mine!!!!!

Joe
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[jcole]

Im the OP. Sorry just now getting back. The ballast are listed for t12 and only t12. I didnt change the lamps because the home owner said the ones in it were brand new. I also made sure that they installed the right ones. I went back today to recheck myself and install new bulbs. I checked the wiring and was wired according to the ballast schematic and the schematic that I printed online. I checked the sockets ( no wires loose, no contacts black, broken,etc.). Still same results - 1 to 2 second delay, bulbs get red on end before they ignite- humming sound that I think is to loud for an "A" rating. I also noticed today when I first turn the switch on, I here like an arch or relay closing sound. I assumed an arch since I am pretty sure there are no mechanical relays in an electronic ballast. The good thing is they are not producing any heat. So I wrote up an invoice and smiled.