T8 lamp confusion

["Wayne Jones" <w.jones at sympatico_ca>]

When someone uses the term T8 they must be careful to include the wattage
and the length of the lamp. Without that information the T8 designation has
very little meaning. T8 only refers to the lamp diameter. There are two
basic types of T8 lamps: those that run at a nominal 265 mA current and
those that run at a nominal 430 mA current. The two types of lamps require
different ballasts and the lamps are not interchangeable. 265 mA lamps must
use electronic ballasts. 430 mA lamps may use either electronic or magnetic
ballasts. Further confusion results from the fact that the same 430 mA lamps
are sometimes labeled with different wattages. In Europe, for instance, a 40
watt 4' T8 is labeled 36 watts. Same rose but different name. Some of those
36 watt labeled lamps are sold in N.A. as well.

For the record, the list of 430 mA lamps in 2', 3', 4' and 5' lengths (with
the European wattages in brackets) is: 20 watt (18 watt), 30 watt, 40 watt
(36 watt) and (58 watt). The 2', 3' and 4' lamps labeled 20, 30 and 40 watt
are available in either T8 or T12 diameters and they all use the 430 mA
magnetic or 430 mA electronic ballast.

The list of 265 mA lamps in 2', 3', 4' and 5' lengths is: 17 watt, 25 watt,
32 watt and 40 watt. These lamps require a 265 mA electronic ballast. These
lamps are not available in the T12 lamp diameter.

I know this is very confusing and it is not something the average consumer
needs or wants to know. The bottom line, however, is that the lamp length
and wattage are required for anyone to know what type of ballast you have or
what sort of lamp you are trying to find.

BTW I believe that the only reason that specialty T8 lamps are expensive is
because in N.A. they require special labeling. Millions of T8 lamps labeled
36 watts are made every year but probably only thousands of T8 lamps labeled
40 watts are made each year. Since the 40 watt lamps are rare, they are
likely to cost more even though they are the same lamp. That's one of the
reasons why Hagen gets away with relabeling a $2 36 watt WW lamp and
repricing it at $20.

Wayne