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Re: Sylvania Quicktronic 32 Electric Ballasts
Just some info regarding Ballast Factors and matching different
flourescent bulbs and ballasts. Here’s a useful Rule of Thumb for
matching flourescent bulbs and ballasts:
If you put a flourescent on a ballast and it lights and the center of
the bulb's glass tube doesn't get above about 120 degrees
Fahrenheit--then you can go ahead and use that combination without
worrying.
That's a good operating temperature for a flourescent -- the ends of
the glass tube where the filaments are located will always burn a bit
hotter than the middle of the glass tube but that's to be expected.
That's the short version of the story. The longer version is this.
Ballast factors are measures of the lumen (light) output of a ballast
for a given bulb relative to that bulb on another ("standard")
ballast. A ballast might have a higher Ballast Factor than another
ballast but that might be due to drawing more energy from the power
line, and therefore passing more energy to the lamp, OR it might be
because it is more efficient than the other ballast (which means it has
a higher POWER FACTOR -- it outputs a higher ration of its input energy
to the bulb). In either case, the bulb will probably have a shorter
life given that it is getting more amps and therefore, running hotter
than it would on a "lesser" ballast.
How do higher amps shorten the life of the bulb?
Higher Ballast Factors generally translate to higher amperages being
allowed to flow through the bulb than ballasts with lower Ballast
Factors. Other things affect lumen output (e.g., higher frequencies of
the AC), but nothing has as much effect as amps. Once is it lit, a
flourescent bulb will take virtually all the amps you give it all the
way up to flashing out from too much heat! The ballast limits the amps
-- hence the moniker, "ballast."
The wide variety of Ballast Factors that are available within a given
wattage range of ballast indicates that flourescents are not too
finicky about how many amps they get within a broad range. Up to a
point, higher amps generate more light. But, at higher amperage, the
filaments evaporate faster. The ends of the glass tube show this by
blackening, which is the vaporized filament materials collecting on the
glass. When the filaments are evaporated too much, they break and
that's the end of life for the bulb. A shorter filament life isn't as
big a problem for aquatic gardeners as other folks, since we don't keep
using bulbs until they "burn out" anyway. But the filaments deposit
some of their opaque black particles farther down the tube, not just at
the ends, so higher Ballast Factors generally mean the amount of light
from a bulb diminishes a little quicker than at lower factors.
90% to 118% Ballast Factors are common but it depends on the "standard
ballast" against which the comparison is made by the manufacturer.
Higher than that and you are probably running the bulb hotter than
"normal" or using a ballast that was very generously rated by its
manufacturer – but they wouldn’t to that, would they? ;-)
85% is a low Power Factor (energy efficiency) rating for bulb these
days. 100% would mean the ballast was perfect and could violate the
laws of thermodynamics. But some expensive ballasts do have Power
Factors well over 90%! However, don’t pay too much for a small
increase in ballast efficiency – the 5 or 10% that the ballast “wastes”
as heat is nothing compared to what the bulbs shed, which is way over
half there input energy.
Scott H.
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