Have just been given some fluorescent light fixtures from a school.
Each four tube fixture has a single 'electronic' ballast. The fixtures
use the skinnier/newer type tubes. I also received some of the newer
type tubes about one inch diameter.
All fluorescent tubes referred to here are the 48 inch style. (Yes I
ran into a few 'metric' ones a few years ago, which are a couple of
I also have older type fixtures. These have non-electronic ballasts and
two tubes per fixture.
Also a generous supply of the older style 40 and 34 watt fluorescent
tubes and spare new and used (non electronic ballasts).
I put a two of the the newer tubes into an old style fixture just to
test them out and they worked but after a while the non-electronic
ballast appeared to overheat and then operated intermittently (probably
due to thermal protection inside it cutting in and out?).
Q1: So it appears that it is NOT possible/safe/advisable to use the
'newer' tubes in 'older' fixtures?
I also put four of the older style tubes into one of the newer
(electronic ballast equipped) fixtures and they worked, fine it seemed.
Q2: So is it OK/possible/safe to use the older style tubes in an
electronic ballast equipped fixture?
Mechanically everything fits fine. Advice appreciated. Terry