Flickering florescents

[K7AAY]

A double circular fixture in the kitchen started to flicker, so I replaced the tubes. Still flickers. I then replaced the starter. Still flickers.

Hmm.

Where to go from here?

Your on-topic answers will be appreciated.

Thank you.

[barry]

How bout the ballast? And it's fluorescent. :')

Next would be a more current fixture.

J

[K7AAY]

Integrated into the starter.

Would leave ugly hole if not plastered/painted. Not good at either.

[Don Klipstein]

Ballasts and starters are different, separate items. If you have only one of these, then you have a ballast - some do not require starters.

I would say get a replacement ballast.

I would also favor getting a more modern fixture and put up with the painting and plastering. A modern fixture with F17T8 or F32T8 bulbs will be brighter, more energy efficient, have better color rendering, and have better future availability of replacement bulbs and ballasts.

Meanwhile, did you replace both bulbs at the same time?

- Don Klipstein ( [e-mail])

[Malcolm Hoar]

It seems that a broken tube can sometimes destroy a good ballast and vice verse.

I've learned to replace everything, at the same time (ballast and both tubes). Then things usually work first time, and continue working for quite a few years.

It also cuts back on:

• Cracked/broken diffusers (from repeated removals and attachements).

• Cuts and scratches from the sheet metal housing

• Multiple trips to the store.

All of which I hate, with a passion.

That too. You might even be able to find a decorative unit that will cover all traces of the original unit.

[terry]

. If it's got a starter is sounds like s pretty old fixture? Long time since dealing with (if in North America?) anything with a starter; except perhaps on a cooking stove etc. If not desiring to change the fixture it might be best to rebuild it using a modern ballast that does not use a starter? The 'mechanicals' of the fixtures are usually no problem and rebuilding it provides a chance to repair, rewire and even to respray the fixture if necessary. f that's too costly just replace. Also done this with electric baseboard heaters, respraying them to an appropriate tone. Good as new then.

[Bob M.]

Get a new ballast. Get the electronic kind if possible; they look similar to the "magnetic" type but run a little cooler, they don't hum and they produce flicker-free light because their operating frequency is in the thousands of Hz.

Go to the local electrical supply place (not Home Cheapo or Lowes) and get a name-brand unit. Since you're into ham radio, cheap units may put out all kinds of RFI, which would be a concern on some ham frequencies.

I don't know if the electronic ballasts are better than the magnetic ones when it comes to RFI; my guess would be that the electronic ballast would have less RFI.

[Professional]

[K7AAY]

Replaced both the tubes and the ballast. No joy. Took one set of tubes back, got another set. Still no joy.

[K7AAY]

Replaced both the tubes and the ballast. No joy. Took one set of tubes back, got another set. Still no joy.

[Don Klipstein]

This makes me suspect:

1. The "platform" is one that I would consider "cranky", such as dual F20T12 on a "trigger start" ballast. The main solution to that if total changeout has failed, maybe even otherwise, is to get a ballast rated to drive two F17T8 "lamps" and a pair of such "lamps" ("bulbs"/"tubes"). (Assuming your problem is with

2-footers)

1. You have improper grounding (the fixture is supposed to be grounded and the ballast case if metallic is supposed to be grounded, usually by mechanical connection to a properly grounded metallic fixture).

2a. You have a hot-neutral reverse somewhere.

Items 2 and 2a can affect electric field (voltage gradient) distribution within "bulbs" trying to start. Start failure of "doing the wrong thing" can be intermittent and vary with temperature and humidity.

1. Some fixtures have starters - those can conk out, and are beaten heavily by bad "bulbs". Furthermore, bad starters at least sometimes can kill bulbs/"lamps"/"tubes".

1. Possibly replacement bulbs/lamps/tubes are not electrically compatible with what the ballast(s) was/were designed for. Only use bulbs/lamps/tubes that the label on the ballast says is suitable. With some lengths, length does not tell the whole story. With some wattages, wattage does not tell the whole story. It might be a good idea to print out a snapshot of the ballast label when shopping for replacement "bulbs". If you are shopping for a replacement ballast, ask for "bulbs" that are electrically compatible (and mechanically compatible with your old ones - bring one in!). This may affect your choice of replacement ballast, maybe even where to buy it (and "bulbs") from.

- Don Klipstein ( [e-mail])