Florescent ballast question

[Lee Schierer]

I need to replace a ballast in a 4 tube suspended ceiling fixture that uses four F32T8 lamps. There are 5 other fixtures that are working so replacing the fixture is not an option. The existing 120 V ballast is an Advance REL-4P32-SC. What numbers are important? Is a ROBERTSON 3P20135, IEA432T8120N /B Fluorescent eBallast the same? How about a Philips Advance ICN4P32N or GE432-120RES-DIY

[Paul F Franklin]

Here are things to compare:

No/type of lamp
Line voltage
Wiring configuration (It's easiest to install if the new ballast requires the same wiring to the lamp sockets as the old. Usually you can reconfigure if you need to, but an exact match is easiest. Wiring is usually shown on the ballast an on the data sheet)
Size/mounting (again, it's usually not a big deal to drill a few mounting holes, but easiest if you don't have to)
Ballast factor (you want to be fairly close to the existing ballast so the light output won't be noticeably greater or lesser than the other fixtures. A variance of .1 or so usually won't be noticeable, but going from 1.1 to .78 definitely would be)
Starting type: Instant vs rapid vs programmed. Just get the same as the original ballast. Most likely instant start.
Low temperature start: Make sure ballast will start the lamps at lowest temperature you anticipate the fixture seeing.

There is usually not a "quietness" issue with electronic ballasts, but I usually read the reviews to see if anyone complains about hum.

I think those are the main things to look for. Advance makes pretty good ballasts; I'd probably just buy another advance.

[Jason Roehl]

I'll second what Paul said--you'll need one that will drive 4 T8 lamps on 120V. Those are the MOST important numbers, but the other factors may matter to you in use as well.

[Doug W Swanson]

Just replaced a ballast on one of my fluorescent fixtures. Just look for the one for 4 lamp 32W T8 lamps and you'll be fine.

[Chris Padilla]

I bought a 10-pack of ballasts for my 4 lamp T8 fixtures and did what Doug above suggested. They work fine near as I can tell.