Motor Help Please

[toland96]

lookin for advice on a problem which may come up (or may not), i have 2 motors on one common shaft 1 duty 1 standby driving a fan, these motors are VSD driven, i have 2no 3phase supplies to the VSDs (Not through contactors) 1 volt free enable for both duty and standby VSD's and 2 seperate 0-10vdc signals to VSD's, question: if i enable the duty fan (this will also rotate the Standby motor) will any voltage be back fed throught the standby windings due to it rotating? If so would this damage the VSD or cause interference to the supply feeding the standby VSD? or am i just an idiot? I havent allot of experience in this feild and would appreciate any help

 

[Darkwood]

Think it depends on the motor really if the motor has permanent magnets in it then turning the shaft will induce a current into the windings and back up the supply cables but if its say like a dc motor with a seperate armature windings and field windings then no as the magnetic flux is created by the power to these seperate windings.

 

[thepurple1]

We do this all the time with no problems or damage to the inverter at all. You will need to set the inverter up for "Flying Start" not "Ramping".
the motors should not cause interference if, silflex cable has been used from the inverter to the motor and grounded both ends

 

[Darkwood]

We do this all the time with no problems or damage to the inverter at all. You will need to set the inverter up for "Flying Start" not "Ramping".
the motors should not cause interference if, silflex cable has been used from the inverter to the motor and grounded both ends

Still wonder as most inverters do state never to put power to the out going terminals in big bold writing i would be inclined to contact tech in this case, again this is only an issue if the motor by design would act as a generator when mechanical energy is applied to turn it. As he hasnt specified the motor or drive its hard to say.

 

[toland96]

Worked grand only small voltage feed back, put delay on changeover as i didnt have the days it takes to read/view the VSD manual/CD Manual to work out which menu/sub menu/sub sub menu/sub sub sub menu you would find the flying start option, lol , appreciate the help tho, cheers