Flourescent Light New Ballast Not Work

[scratchedup]

I replaced the ballast on a 23 year old basic fluorescent 2 tube 42" fixture.

[Fluorescent eBallast for 2 F40T12 Linear Lamps, Preheat- Rapid Start, 120Vac, 50-60Hz, Normal Ballast Factor, NPF]

When I apply power (120v) the light/tube ends glow but the light does not come on, however, if I touch the tubes it comes on...

Repeated several times.

Any help?

Or does this need to go to land fill

 

[Bert_]

Make sure the ballast and fixture are grounded. That makes a difference with rapid start ballasts, NPF (normal power factor) and LPF (low power factor) ballasts seem to be more prone to this issue than HPF (hig power factor).

Most of these ballast will actually have something to the effect of "mount lamps within 1/2" of grounded metal reflector" printed on the label.

 

[scratchedup]

OK
Let me check....
Do I run a ground wire from the fixture body/case to ground.... there appears to be no ground wire.

 

[ard]

OK
Let me check....
Do I run a ground wire from the fixture body/case to ground.... there appears to be no ground wire.

Yes. Assuming the fixture itself will ground all metal parts on the basis of it's construction.

 

[BillK]

Scratch,
Don't rule out a defective ballast. I replaced one at my shop about a year ago and had the same exact issue. Returned the ballast and got another one and the problem was fixed.

 

[snyder]

Double check your wiring. Make sure the wires are
Clipped into the end caps securely. Check for burnt or broken tabs in the end caps. After that it could be a bad ballast.

 

[dscheidt]

I replaced the ballast on a 23 year old basic fluorescent 2 tube 42" fixture.

[Fluorescent eBallast for 2 F40T12 Linear Lamps, Preheat- Rapid Start, 120Vac, 50-60Hz, Normal Ballast Factor, NPF]

When I apply power (120v) the light/tube ends glow but the light does not come on, however, if I touch the tubes it comes on...

That's a sign the reflector isn't grounded. When the tube starts, a capacitor is formed between the tube wall and the reflector. Charging the capacitor causes current to flow, which ionizes some gas in the tube. That makes striking the arc easier. if the reflector isn't ground, you don't get the capacitance or the current flow, so the arc is harder to strike. Touching the tube forms a capacitor between your hand, and the inside of the tube wall, and lets the arc gets started.

Is there a reason you didn't use a t8 ballast? They, and t8 tubes, are more efficient.

 

[walta]

1 Did you say both lamps are new?

2 Do you really have a 42” fixture?

3 You will need a good ground connection from the electrical panel to the reflector.

4 Are the lamps you installed T12? T8s will be too far from the reflector.

5 Rapid start ballasts are 1950 technology. When they fail now is time to replace them with modern electronic ballasts. You will have lower electric bills, brighter lights and reliable start.


Walta

 

[scratchedup]

Fixture old...25+ years...
Tubes 48"- F34CW.RS.ECO
Tubes have been replaced but they are pretty old but still work.
Ballast off Amazon ~ $13.

Got up this morning are the thing seems to be working. I will set a ground wire. I think years ago I threw this up with out using the ground wire. The Nomex? power supply still has the bare ground wire unused.

 

[scratchedup]

This is the ballast-
ROBERTSON 3P20132 Fluorescent eBallast for 2 F40T12 Linear Lamps, Preheat- Rapid Start, 120Vac, 50-60Hz, Normal Ballast Factor, NPF, Model RSW234T12120 /A (Crosses to 3P20010 Model RSW240T12120 /B)

 

[FTG-05]

I would never replace a ballast on flor light fixture. Total waste of money that produces zero light in and of itself.

Instead, replace the flor light bulbs with LED ballast bypass bulbs.

Let's count the advantages:

- No more ballast = no more ballast failures
- Higher output and more efficient light i.e. +110 lumens/watt
- Instant on regardless of temps
- No more flickering or buzzing and no real possibility of either ever
- Cost? About the same as a new ballast +/-

Disadvantages:

- You have to rewire the light fixture; no real biggie unless you're a wiring virgin

Good luck.

 

[American Locomotive]

This is the ballast-
ROBERTSON 3P20132 Fluorescent eBallast for 2 F40T12 Linear Lamps, Preheat- Rapid Start, 120Vac, 50-60Hz, Normal Ballast Factor, NPF, Model RSW234T12120 /A (Crosses to 3P20010 Model RSW240T12120 /B)

Rapid start ballasts really need the fixture or ballast to be grounded to start properly and reliably. There's a ground wire going to the fixture, hook it up.

 

[cybrdyke]

The ballast that you wanted has been discontinued for years. The 34 watt lamps that you used are likely not the same as the version that used to be out there. Your old ballast had no trouble firing them.
So now, you have old lamps that are reduced wattage (energy saving) and a ballast with a low ballast factor (.81).
They just dont work together very well. The new ballast hasn't got the voltage to fire the tubes completely. They'll start sometimes, other times not so much. Probably when you need them the most.
As was discussed above, either change the ballast to T8 Instant Start or bypass it entirely and use LED tubes.
Good luck,
CD