Venkates

Please refer the images.Please note down the RED mark in drive image.In my factory their is an grinding machine in which they used this drive to drive the motor.The mainboard was burnt down so i tried to start the motor manually.From the machine I observed,1.It operating in single phase power supply(Given to R and S) and three phase output(U,V,W) is given to the motor.2.STF and SD are given to the control board.3. 10 and 2 shorten down using an small wire.By this they controlling the speed of the motor.My doubts are,1.Is STF and SD are acting as switch to switch ON/OFF the motor..?By connecting an simple switch across the STF and SD to control the motor.If we connected the switch means we can switch ON the motor manually..?2.In datasheet they adviced to use an 1/2W,1K POT to control the speed of the motor.But here they shorted 10 and 2.Byt this way how they controlling the speed of the motor..?

Hello kraykov,If I want to control the speed of the motor means,shall I remove the loop between 10 and 2 and shall I connect an 1/2W 1K POT across 10,2,5 to control the speed of the motor..? After providing an single phase supply to the drive,if STF or STR is closed with SD means only the motor will operate in either forward or reverse direction,otherwise it will in idle state.Is it right..?   For operating motor in any direction shall we use an simple optocoupler MOC3061 to connect STF or STR with SD..?