Application Guide

63-706223
7.5 kw 4 pole
20
30
40
50
60
70
80
90
100
110
Ambient
50Hz
40Hz
30 Hz
20Hz
15 Hz
Temp Sensor 1
Temp Sensor 2
°C
Fig. 26. Motor on constant full load torque.
Test 5 Motor Run on Old and Modern-Design VFDs at 50 Hz on Full Load torque.
As a final test, Fig. 27 shows a comparison in the heating effects of running a motor first on a 10 year old design VFD and a
modern VFD. The graph shows that under similar load and ambient temperatures, the old design VFD caused the motor
temperature to rise to 75°C whereas on the modern design, the motor temperature reached 68°C. The reason for this reduction
in temperature is the improvement in the synthesis of the output waveforms, to the motor.
10
20
30
40
50
60
70
80
7.5 kw 4 pole motor
Early Generation
Modern
Design
°C
Fig. 27. Comparison of early generation and modern VFDs.