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Owen Duffy · June 12th 08, 06:50 AM posted to rec.radio.amateur.antenna

(Richard Harrison) wrote in
:

Owen Duffy wrote:
"Most supply authorities would not allow you to connect a capacitive
load (a leading PF load),-----."

Incorrect. Overexcited synchronous machines are commonly used to
correct the power factor causing reduced line current and lower power
loss on the a-c power transmission line.

In this part of the world, connection of an overall leading PF load
usually requires approval of the supply authority. Most electricians
would be aware of the restriction.

The reason being is that it can cause an increase in supply voltage
beyond spec in the local area.

Yes, large factories for example may use static or rotary power factor
correction to improve their PF for tariff reaons, but if an installation
reaches an overall leading PF it usually breaches rules in this part of
the world, and commonly permission is required to attach individual
'devices' with capability for leading PF. Some tariffs are based on
maximum demand, and often maximum apparent power (ie VA), not maxiumum
real power (ie W), hence the economic interest in PF correction.

Today, active static power factor correction that can dynamically track
a varying load at varying PF is a lot more attractive than rotating
machines.

Owen