Problem with fluorescent lamp or ballast

Bob Vila would love this group, post #109,268
Author:
Date:
Subject:
 Yong Huang
 2008-07-20 15:46:26
 Problem with fluorescent lamp or ballast
One pair of the fluorescent lamps in the kitchen stopped working. I
replaced with the other pair in the same big box on the ceiling. They
still didn't work. Then I bought a ballast from Home Depot, a magnetic
type, and installed it. One of the two bulbs can flash with dim light.
I did this before (in a different place). Replacing ballast and all
was well. But this time I'm at a loss.

Can somebody tell me how I check the ballast or circuit? I did all the
following measurements. Both ballasts are like this:

_________
Blk | | Blu
W | | Blu
Y | | R
Y |_________| R

Old ballast:
Blk to W: 12ohm; Y to Y: <2 ohm
Blu to Blu or R to R: <2 ohm; no continuity between Blu and R
Blk to Blu: 3ohm; W to Blu: 10ohm

New ballast:
Blk to W: 8ohm; Y to Y: no continuity
Blu to Blu or R to R or : no continuity
Blk to one Blu: 1.5ohm; Blk to the other Blu: no continuity
W to the first Blu: 8ohm; W to the other Blu: no continuity

After I turned power on, I checked the voltage on the wires when the
new ballast is installed:
Blk: 120v; Y and W: 0
Blu: 120v; one R: 0; the other R: 140v

Of all the 4 sockets (for 2 bulbs), one which 2 blue wires go in has
120V. The other 3 are 0.

I don't know what I should measure exactly. Thanks for help.

Yong Huang
Author:
Date:
Subject:
 Art
 2008-07-20 20:04:29
 Re: Problem with fluorescent lamp or ballast
Before you changed the ballast you should have checked the bulb contacts for
corrosion. I had a fixture driving me nuts and finally decided to abraid
the contacts by removing and replacing the bulbs about 20 times. That was 2
years ago and the fixture has been working great since.

By the way a tip for anyone with flourscent fixtures in the garage. This
has been posted before but a long time ago. If your area suffers from cold
weather and bulbs don't work well in winter, by those cheap flourscent tube
protectors. They help the bulbs warm up much faster and the bulbs will be
bright even in a cold winter.


"Yong Huang" <[email protected]> wrote in message
news:2e1d9d34-428e-41d6-a1a0-75052986aac4@m73g2000hsh.googlegroups.com...
> One pair of the fluorescent lamps in the kitchen stopped working. I
> replaced with the other pair in the same big box on the ceiling. They
> still didn't work. Then I bought a ballast from Home Depot, a magnetic
> type, and installed it. One of the two bulbs can flash with dim light.
> I did this before (in a different place). Replacing ballast and all
> was well. But this time I'm at a loss.
>
> Can somebody tell me how I check the ballast or circuit? I did all the
> following measurements. Both ballasts are like this:
>
> _________
> Blk | | Blu
> W | | Blu
> Y | | R
> Y |_________| R
>
> Old ballast:
> Blk to W: 12ohm; Y to Y: <2 ohm
> Blu to Blu or R to R: <2 ohm; no continuity between Blu and R
> Blk to Blu: 3ohm; W to Blu: 10ohm
>
> New ballast:
> Blk to W: 8ohm; Y to Y: no continuity
> Blu to Blu or R to R or : no continuity
> Blk to one Blu: 1.5ohm; Blk to the other Blu: no continuity
> W to the first Blu: 8ohm; W to the other Blu: no continuity
>
> After I turned power on, I checked the voltage on the wires when the
> new ballast is installed:
> Blk: 120v; Y and W: 0
> Blu: 120v; one R: 0; the other R: 140v
>
> Of all the 4 sockets (for 2 bulbs), one which 2 blue wires go in has
> 120V. The other 3 are 0.
>
> I don't know what I should measure exactly. Thanks for help.
>
> Yong Huang
Author:
Date:
Subject:
 Father Haskell
 2008-07-20 18:59:16
 Re: Problem with fluorescent lamp or ballast
On Jul 20, 6:46 pm, Yong Huang <[email protected]> wrote:
> One pair of the fluorescent lamps in the kitchen stopped working. I
> replaced with the other pair in the same big box on the ceiling. They
> still didn't work. Then I bought a ballast from Home Depot, a magnetic
> type, and installed it. One of the two bulbs can flash with dim light.
> I did this before (in a different place). Replacing ballast and all
> was well. But this time I'm at a loss.
>
> Can somebody tell me how I check the ballast or circuit? I did all the
> following measurements. Both ballasts are like this:
>
> _________
> Blk | | Blu
> W | | Blu
> Y | | R
> Y |_________| R
>
> Old ballast:
> Blk to W: 12ohm; Y to Y: <2 ohm
> Blu to Blu or R to R: <2 ohm; no continuity between Blu and R
> Blk to Blu: 3ohm; W to Blu: 10ohm
>
> New ballast:
> Blk to W: 8ohm; Y to Y: no continuity
> Blu to Blu or R to R or : no continuity
> Blk to one Blu: 1.5ohm; Blk to the other Blu: no continuity
> W to the first Blu: 8ohm; W to the other Blu: no continuity
>
> After I turned power on, I checked the voltage on the wires when the
> new ballast is installed:
> Blk: 120v; Y and W: 0
> Blu: 120v; one R: 0; the other R: 140v
>
> Of all the 4 sockets (for 2 bulbs), one which 2 blue wires go in has
> 120V. The other 3 are 0.
>
> I don't know what I should measure exactly. Thanks for help.
>
> Yong Huang

Do the tubes light up when you brush a hand over them?
Check your ground. Tubes must be within 1/2" of a
grounded metal surface (the chassis) or they won't
start.