Re: Servo Motor voltage & current when disc. from Inverter
Originally Posted by
AmazingServo
I have a basic questions in general on a AC Servo Motor.
1. Does spinning the servo motor by hand, generate current or voltage?
It generates voltage. Think of a water pipe (conductor), if there is no pressure (voltage) then there is no water flow (current). If there is a valve in the water system then that restricts (resistance) the flow.
So if you turn the motor shaft voltage will be generated, if there is a path for current to flow then there will be current flow in the conductor. It might be possible to generate enough voltage to damage the winding insulation if the motor is turned fast enough without the windings beings shorted or connected to something.
2. When the servo motor is running at its maximum speed, and i remove the inverter from the AC motor. Will it still have current and voltage on it? What will it be?
It depends on the resistance of the system. Disconnecting the inverter from an operating motor can cause a voltage spike that may damage both the motor and the inverter.
3. When it is coasting after disconnected from an inverter, by applying brake to the motor, what will the current and voltage (if there are any) looks like?
That would be a more proper way to do it. The energy stored in the system would be disipated as heat in the brake.
4. If the motor is disconnected from the inverter, what will the servo motor do if i short both lead together?
It will stop as fast as it can, but this is not the proper way to slow down a motor.
5. If i were to short the motor lead, what current do i see from the servo motor?
It depends on the resistance of the system. A short would cause a lot of current flow which would be disipated as heat in the motor windings, and could possibly damage the motor windings.
Hope someone can clarify this for me.
THanks!
The bottom line is: Do not disconnect the motor from the inverter, simply send the stop signal to the inverter, and if the inverter is set to ''coast to stop'' apply a mechanical brake if you like.
Jim Dawson
Sandy, Oregon, USA