Hi all,
I'm looking at an application with a Powerflex 755 with encoder feedback, being run as a standard VSD (as opposed to a motion axis), with a simple frequency reference, but the requirement to limit the torque to avoid damage to the mechanical system in the event of a jam. This is replacing an existing dual-winding two-speed DOL motor with some kind of electronic torque limiting arrangement for which I have no details yet.
In reading through the programming manual I can see that I can set torque limits in % (parameters 670/671), and that I must have the drive in flux vector mode (parameter 35 = 3). My questions are:
1. Are there any other drive parameters I need to be aware of in order to set this up correctly?
2. What will happen if there is a mechanical obstruction and the drive hits the torque limit? Will it trip on some kind of fault or just sit there not moving (or moving slower than the desired speed reference) and drawing the specified amount of current until someone notices?
3. How can I calculate the equivalent % torque limit to match the old motor, given that the only information I have is that it's set to "6.7kW at 1430rpm"?
Thanks for any insights!
I'm looking at an application with a Powerflex 755 with encoder feedback, being run as a standard VSD (as opposed to a motion axis), with a simple frequency reference, but the requirement to limit the torque to avoid damage to the mechanical system in the event of a jam. This is replacing an existing dual-winding two-speed DOL motor with some kind of electronic torque limiting arrangement for which I have no details yet.
In reading through the programming manual I can see that I can set torque limits in % (parameters 670/671), and that I must have the drive in flux vector mode (parameter 35 = 3). My questions are:
1. Are there any other drive parameters I need to be aware of in order to set this up correctly?
2. What will happen if there is a mechanical obstruction and the drive hits the torque limit? Will it trip on some kind of fault or just sit there not moving (or moving slower than the desired speed reference) and drawing the specified amount of current until someone notices?
3. How can I calculate the equivalent % torque limit to match the old motor, given that the only information I have is that it's set to "6.7kW at 1430rpm"?
Thanks for any insights!