Re: Anyone moved to LED Lighting?

["Josepi" <JRM@xxxxxxxxxxxx>]

The generator has to produce all the power consumed by the load, where it is
desired and the delivery system and generator.

Lets say you have a 120watt bulb at unity pf it would consume 1ampere x
120volts x cos< = 120 watts

If we have a 120watt bulb with a poor PF, say 50% PF (for easy figurin') we
now have
 2amperes x 120volts x cos60< (pf=50%) = 120watts.

The generator has to produce the bulb load (120watts) and the losses in the
generator and syetm at 2 amperes. This amounts to double the losses in the
conductors, transformers, generators, tap changers and all delivery
equipment. With twice the current , twice the heat is generated in
laminations and coils.

This is all losses to the energy source being converted by the generator.
Not twice the total load but twice the twice the delivery and generating
system losses. This can vary from a few percentage points to over 100% of
the end load value in long systems.

Harmonics generated in lighting gets really weird and plays havoc with
average sensing voltage control systems and many systems with neutral
reactors. These reactors are a few ohms at 60Hz and increase with harmonics.
On faults they stop the system from severe damage due to electrcal
explosions in the tens of thousands of amperes and give time for the
protection to take out a circuit more safely. On unbalanced loads or thrid
harmoinics all the phase line up and make three times the third harmonic
current in the neutral.. This becomes a big problem for distribution systems
and your motor love it. They burn out.



"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
news:4b3b8650.24099578@xxxxxxxxxxxxxxxx
I'm still not clear on this. 50 years ago when the USAF taught me
electronics there was only a brief discussion of reactive power where
current is stored and then released out-of-phase. That was fairly
straightforward. I don't recall any mention of THD (at least in relation to
power lines) so I don't have a good grasp of the issues with SMPS. And, it's
not clear to me whether PF as it relates to CFL/LED incorporates THD.

You and Don (and Cummins) seem to be saying that low PF adds to the
generator load but the increased load is not linearly proportional to PF.
How is this calculated?


"Josepi" <JRM@xxxxxxxxxxxx> wrote:
>Power delivered to the load is the main required energy input to the
>generator.
>
>However,
> losses in the delivery equipment and the generation equipment is due to
> the
>current or VA required to deliver power to the load. eg. Heating in the
>windings of the generator is due to the current passing through the
>windings
>and is not related to the usage (watts) the load makes from the source