Sanken Samco SVC06, Instruction Manual, Page: 118 / 136

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10-5 Electrical Measurement of Main Circuit
10-5 Electrical measurement of main circuit

Since the voltages and currents of the main inverter circuit at the input (power supply) and output (motor)
contain harmonic components, measured values may differ depending on the meter used. When using a
commercial frequency meter, select one of the types listed in the table below.

The power factor cannot be measured with a commercial power-factor meter that measures the phase
difference between voltage and current. Measure the voltage, current and power separately at input/output
and calculate the power factor using the following formula:
Inverter
Three-phase
power supply
Motor
Figure 10-4 Power measurement circuit for main circuit
Table 10-4 Main circuit measuring instruments
Symbol Item Measuring instruments
Power supply current Moving-iron type AC ammeter
Power supply voltage Moving-iron type AC voltmeter
Power supply power Electrodynamic single-phase power meter or
Digital power meter
Power supply power
factor Digital power meter (can be calculated with the measured
power supply voltage, current and power)
Output voltage Rectifier type AC voltmeter or
digital power meter
Output current Moving-iron type AC ammeter or
digital power meter
Output power Electrodynamic single-phase power meter or
Digital power meter
Output power factor Digital power meter (can be calculated with the measured
power supply voltage, current and power)
[W]
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