Tips And Hints - Fluke 434-II User Manual

Fluke 434-II/435-II/437-II
Users Manual

Tips and Hints

A power system is utilized in an optimal way if voltage and current are sinusoidal, in
phase, and balanced. Any deviation from this will cause efficiency loss and thus waste of
energy.
A poor power factor is usualy caused by reactive devices such as transformers and
motors. The power factor can be improved by adding capacitors in parallel with the
inductive load. The ideal situation is a cos phi or DPF equal or close to 1.
Reactive powers (var) do not contribute to efficient energy transfer. They are not
included in the real power (W, kW) measurement, but cause energy losses due to wire
resistance. Additionally utilities may charge additional cost when var readings are high
because they need to provide apparent power (VA, kVA) that does not include both var
and W.
Unbalanced powers and harmonic power are included in Watt measurement of energy
usage meters so that the user has to pay for it. But these powers can not be converted
effectively into mechanical energy and are therefore considered loss.
Increasing the diameter of conductors reduces copper loss (Effective kW).
If harmonics are present, consult a qualified engineer before installing capacitors. Non-
linear loads such as adjustable frequency motor drives cause non-sinusoidal load currents
with harmonics. Harmonic currents increase the kvar and thereby decrease total power
factor. A poor total power factor caused by harmonics requires filtering for correction.
In general the most efficient way to troubleshoot electrical systems, is to begin at the load
and work towards the building's service entrance. Measurements are taken along the way
to isolate faulty components or loads.
12-4
info@Fluke-Direct.ca
Fluke-Direct
.ca
1.800.868.7495