Product Manual

Motor Analyzer
Motor Analyzer Parameters
13
Voltage Harmonics
Harmonic currents are introduced when the line voltages applied to the motor include voltage components at
frequencies other than the fundamental frequency of the supply (50 Hz or 60 Hz).
The temperature of the motor operating at a particular load and per unit voltage harmonic factor will
therefore be greater than that for the motor operating under the same conditions with only voltage at the
fundamental frequency applied.
When a voltage is applied to the motor that consists of components at frequencies other than the
fundamental frequency, the rated power of the motor should be derated according to the Derating Factor
shown below.
The Harmonic Voltage Factor (HVF) is defined as:
The total derating is found by multiplying the Derating due to Unbalance and due to Harmonics.
To open:
1. Go to the ANALYZER screen.
2. Push .
The Derating screen shows the Motor Load (vertical axis) relative to the advised derating due to voltage
unbalance or voltage harmonics (horizontal axis).
n = order of odd harmonic, not including those divisible by three
Vn = the per-unit magnitude of the voltage at the nth harmonic frequency