According to :
On completion of a 3 phase converter and after adjusting the voltages
with caps what effect does adding the power factor corrections cap have
on the commercial power meter reading.Does it add more or less power to
the power bill?
It depends on what you mean by the phrase "commercial power
meter". If you mean the average home meter, it would result probably in
a tiny reduction -- corresponding to the extra power wasted heating the
wiring from the higher out-of-phase current.
However -- at least *some* commercial *users* of power --
especially those with three phase to their shops -- are charged "demand"
metering, which can be sensitive to the out-of-phase current so they are
charged based on that -- and on the *peak* demand during a given period.
So -- run a high-current heat-treat oven (for example), for an hour or
two, and you wind up paying a *lot* more *per* *month* for several
months, until they are sure that it will not repeat. (You are being
charged for the worst-case power which you *might* use, not what you are
actually using on the average.)
Since you've built a rotary converter, I presume that you don't
have an industrial power contract, so you will get a very small
improvement in your power bill -- but you will get fewer nuisance trips
of your circuit breakers. (Depending on how close to the trip point the
"imaginary" power takes you.) The breaker works on the vector sum of
the real and imaginary power, while the home meter works only on the
real, so it is mostly a good thing to add the power factor correction,
especially if you are going to be running other (single-phase) equipment
off the same breaker.
My guess is that it would add more power to the bill as the power
factor approached zero(voltage in phase with the current)
Not so. The power which you draw doing actual work is the real
power, and you'll be charged for that in any case. ("Actual work" can
include things like the heating of wiring by the out-of-phase component
of an uncorrected power factor.)
Now -- another factor comes into the game here. The power
factor correction is only good for a single level of load. As you
increase or reduce the load level, the power factor will be somewhat
less well corrected.
So -- if you are likely to spend more time with the rotary
converter idling than actual machining time (e.g. you turn on the
converter when you come into the shop, and turn it off when you leave
for the day), but only run the machines say 20% of that time, you are
better off with the power factor correction tuned to the unloaded
converter. But, if you turn on the converter just before turning on the
machine, and then turn it back off just after you stop the machine, it
would be better tuned for the converter plus the machine running a
typical cutting load. (However, you draw more current when starting the
converter, so you will probably save more running with the converter on
most of the time you are in the shop, ready to start the machine.
Hence according to my ramblings it would be better not to correct power
factor and let the power company worry about it.
My opinion is that it would be better to correct the power
factor to save wear and tear on your breakers and wiring -- *and* heat
buildup in the idler motor as well.
Good Luck,
DoN.
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