On 05/05/2018 22:48, Johnny B Good wrote:
On Sat, 05 May 2018 18:02:11 +0000, Andrew Gabriel wrote:

In article ,
harry writes:

I saw a similar device that purported to save significant energy by
power factor correction.
Bollix of course.

Commercial users can be charged extra for low power factor and badly
balanced 3-phase loads. When I worked for GEC Computers in the 1980's
our computer room supply was charged at some favourable rate because it
was a pretty constant load (around 2MW IIRC), but it was charged as
though all phases were drawing the same load as the highest phase,
so you wanted the load well balanced. The computers were all single
phase, so it was important to distribute them carefully between phases.

Domestic users in UK have to be charged based on energy used, and can't
be charged for low power factor or unbalanced 3-phase loads.

Regulations on domestic appliances takes care of the low power factor
issue in domestic premises, allowing the PSU to only charge their
domestic customers for KWHs used without the complication of monitoring
and charging for excessive reactive current 'consumption'.

For example, magnetically ballasted fluorescent lamp fittings must
incorporate a PFC capacitor for lamps of 20W or more rating. The SL13 and
SL18 CFLs made by Philips Lighting some three(?) decades back did not
require a PFC capacitor to be fitted into these magnetically ballasted
CFLs since they fell below that 20W limit, even allowing for a +/-10%
margin of error in their 18W SL18 lamps.

It wasn't only the sheer mass of a larger magnetic ballast that a higher
wattage version would have entailed that limited those early CFLs to a
maximum of 18W, it was also the fact that the mandated PFC capacitor
would have added further bulk (and a modest further increase in mass) to
an already heavy and ugly looking lamp.

Are domestic air conditioners and heat pump heaters required to have
power factor correction?

--
Max Demian

On Sat, 05 May 2018 23:02:58 +0100, Max Demian wrote:

On 05/05/2018 22:48, Johnny B Good wrote:
On Sat, 05 May 2018 18:02:11 +0000, Andrew Gabriel wrote:

In article ,
harry writes:

I saw a similar device that purported to save significant energy by
power factor correction.
Bollix of course.

Commercial users can be charged extra for low power factor and badly
balanced 3-phase loads. When I worked for GEC Computers in the 1980's
our computer room supply was charged at some favourable rate because
it was a pretty constant load (around 2MW IIRC), but it was charged as
though all phases were drawing the same load as the highest phase,
so you wanted the load well balanced. The computers were all single
phase, so it was important to distribute them carefully between
phases.

Domestic users in UK have to be charged based on energy used, and
can't be charged for low power factor or unbalanced 3-phase loads.

Regulations on domestic appliances takes care of the low power factor
issue in domestic premises, allowing the PSU to only charge their
domestic customers for KWHs used without the complication of monitoring
and charging for excessive reactive current 'consumption'.

For example, magnetically ballasted fluorescent lamp fittings must
incorporate a PFC capacitor for lamps of 20W or more rating. The SL13
and SL18 CFLs made by Philips Lighting some three(?) decades back did
not require a PFC capacitor to be fitted into these magnetically
ballasted CFLs since they fell below that 20W limit, even allowing for
a +/-10% margin of error in their 18W SL18 lamps.

It wasn't only the sheer mass of a larger magnetic ballast that a
higher
wattage version would have entailed that limited those early CFLs to a
maximum of 18W, it was also the fact that the mandated PFC capacitor
would have added further bulk (and a modest further increase in mass)
to an already heavy and ugly looking lamp.

Are domestic air conditioners and heat pump heaters required to have
power factor correction?

The regulations will only state that they have to meet a minimum PF
figure. I don't know the details but I'm sure the manufacturers will take
whatever measures are required to meet such mandatory requirements (PFC
capacitors or a motor design that intrinsically has a high enough PF
figure to meet the requirement without such devices).

The case of 20W and above rated fluorescent light fittings is the only
one I recall but if the need to correct the PF on 20W fluorescent lamps
is mandated by the regulations, you'd think other much higher wattage
domestic appliances will also be subject to a minimum PF requirement.
However, it's proving very difficult to track down a definitive answer to
this very question other than for new regulations concerning PFC
requirements on SMPSUs rated from 75W to 600W (class D).

--
Johnny B Good