"Mr_Bill" wrote in message
ups.com...
First, to restate the problem. I have 2 FSC3024 undercab lighting
modules. Each module consists of 2 8W T5 flourescents and a
single (complex) electronic ballast. These 2 FSC3024's are
wired in parallel and run back to a single pole switch. One T5
tube went down, and brought down the other tube in the same 3024 module
and one (?) of the tubes in the other module. When I changed the one
bad tube, everything lit up. Everything ran ok for 1 yr before this
happened. The switch is a
Lightoleer MSP600NDW, one of those fancy-pants
switches (non-dimmer) which is controlled by a "master" over an
ASCII bus, and which can be manually overridden. When 3 out of
4 tubes were dark I bypassed the switch, hardwiring to "hot". No
change, i.e. 3 out of 4 tubes still dark.

The wiring isn't exactly rocket science, but anyway I checked the
voltage to each ballast and it reads 119.6vac from hot to neutral, both
when the fault is showing and when everything is lit up.

I was hoping someone had encountered this before.

My only theory is that the electronic ballasts are of a lousy design,
and that they "crosstalk" to each other, i.e. they put out some kind of
noise spikes, especially when the load on the ballast drops below 16W.

Has anyone seen this type of behavior before. Have you had trouble
with FSC electronic ballasts?

Bill



Chris Friesen wrote:
Mr_Bill wrote:
I have under-cabinet fluorescent lights. Two
light fixures in parallel, wired to one single pole switch.
Each light fixture consists of 2 13W tubes, driven
by a "ballast".

Today, 3 out of the 4 tubes went dark. Long story
short, all is well after I replaced only *one* tube.

Anybody know what's going on?

I'd guess they're not properly wired in parallel.

Chris

To find out what is happening you need to see if the problem is repeatable.
Put the "bad" tube in and out several times to see if the three others
always fail to light when it is in. It is common for two tubes on a common
ballast to go out when one tube fails or is removed. I strongly suspect that
the other two tubes going out was caused by something other than the one bad
tube. Poor grounding of the metal reflector can cause some rapid-start tubes
to not light.

Don Young