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gregz

gregz wrote:
"Pete C." wrote:
wrote:

On Mon, 19 Nov 2012 13:21:48 -0600, "Pete C."
wrote:

wrote:

On Mon, 19 Nov 2012 12:23:22 -0600, "Pete C."
wrote:

ps56k wrote:

I had to replace the burned out FL long straight tube in my shop light,
and noticed the marking indicated "40 watt".

I was thinking - our twist CFLs that replaced the our 60 watt bulbs
are only running about 14 real watts.

SO - are the traditional long straight tube FL shop lights actually using 40
watts,
or is that just and equiv and the real watt usage is much less, just like
the CFL ?

If not - then that means the long tube FL are as in-efficient as a normal
bulb.
--
/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/ _/
No Good Deed -
Goes Unpunished

They use 40W, they will be producing the light equivalent to ~150W of
incandescent lamps. Unfortunately, few people these days seem able to
understand what efficiency really means, or calculate the MPG their car
gets

Just a little gee whiz info
I put a clamp on the hot side of the line cord of a regular 2 tube
shop light and the whole thing, ballast and all is about 0.48-49 amps
and a line voltage of 123 VAC so the whole thing is about 60 watts.
I am not sure where the "40w" comes from.
Maybe that was based on the old style magnetic ballast.

True RMS meter? The missing 20W could be hiding in a distorted
electronic ballast waveform.

That might be true, the DL250 manual says

"AC readings displayed on this meter are average responding, True-RMS
indicating. They are based on a true sinusoidal waveform."

The T8 tubes are 32W also, while the T12 are 40W. Not sure which you
have in the fixture you measured.

There ARE 32 watt t12's or something less than 40 watts.

Greg

Years ago I noticed how much brighter the new tubes were, and they didn't
change ballasts, and they were 32 watts.

Greg