In article ,
405 TD Estate writes:
I tested an old 20W osram fluurescent bulb with built in ballast and
it read 14W 0.75 power factor

It means the power drawn (14W) is 0.75 times what you would think if
you simply measured the RMS current and multiplied by the RMS voltage.
So you need to size the wires and fuses as though it was an 18.67W
lamp, although you will only be charged for the 14W it really uses.

A new compact 11W fluurescent bulb read 12-14W 1.00 power factor.

The old 20W bulb was noticeably brighter than the new compact.

As already stated, this is nothing to do with power factor.

--
Andrew Gabriel
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