Scenario:Variable Speed Drives (VSDs) by design generate pulses which have fast rising edges.
These pulses can create voltage reflections.
The magnitude of the reflected wave voltage is depending on cable length, motor load, motor and cable surge impedance and the rise time, spacing and magnitude of drive pulses.
In some cases, over time, these voltages can overstress the cable and motor insulation. Don't leave a critical operation to chance!
- How close are the transient peaks coming to the maximum rating of the motor?
- Will the motor insulation break down?
- Show me how to diagnose PWM peak voltage using a multimeter and a scope.
The more you see—the more you can fix.
- View this video to find out more (.swf) »