Fluke 43B Application Guide

Motor Loads
Induction Motors
4
49
4
Move the red test lead and the current probe to phase 2 (keep the black
test lead attached to phase 3).
Write down the value for true power reading (kW
2
). If the power factor is
smaller than 1, kW
1
and kW
2
will be different even if the load currents are
equally balanced. Note that the apparent power (kVA) is equal to the first
measurement.
5
Calculate the power factor (fill in your measurement results):
___ kW
1
+ ___ kW
2
___ kW
TOTAL
= = _____
√
√√
√3 ∗
∗∗
∗ ___ kVA ___ kVA
Example
Measured: kW
1
= 170 kW kW
2
= 68 kW kVA = 188 kVA
170 kW + 68 kW 238 kW
TOTAL
= = 0.73
1.73 ∗ 188 kVA 325,6 kVA
Poor power factor can be improved by adding capacitors in parallel with the
load.
If harmonics are present, consult with 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
kVA and thereby decrease total power factor. Poor total power factor caused
by harmonics requires filtering for correction.

Fluke 43B Specifications

General

Category	Power Quality Analyzer
Interface	RS-232
Volts AC/DC	Yes
Ohms	Yes
Continuity	Yes
Diode Test	Yes
Capacitance	Yes
Harmonics Measurement	Up to 51st harmonic
Display	LCD
Battery Life	Approximately 6 hours
Weight	1.1 kg (2.4 lb)
Data Storage	Yes
Amps AC/DC	0.1 to 1000 A (with clamp)
Power Measurement	W, VA, VAR, PF
Dimensions	50 mm
Current Measurement Range	Via current clamp accessories (not built-in)