Posted 25 Jul 2017 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..? Share this post Link to post Share on other sites
Posted 25 Jul 2017 (edited) Hello Venkates, the STR and STR terminals are used to start the engine forwards and backwards respectively. By doing so, the connection between terminals 10 and 2 set - 100% reference for speed. Edited 25 Jul 2017 by kraykov Share this post Link to post Share on other sites
Posted 26 Jul 2017 (edited) 17 hours ago, kraykov said: Hello Venkates, the STR and STR terminals are used to start the engine forwards and backwards respectively. By doing so, the connection between terminals 10 and 2 set - 100% reference for speed. 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..? Edited 26 Jul 2017 by Venkates Share this post Link to post Share on other sites
Posted 26 Jul 2017 Hello Venkates , On the first question - remove the link between 10 and 2 and connect a potentiometer as given on your picture. Its value may be from 2.2k to 10k. The second question - there is no problem to use the optocoupler connected between the STF and the SD terminals for start forward and another optocoupler between the STR and the SD terminals for start reverse. The current is small in this circuit around 4 - 8mA Share this post Link to post Share on other sites