Motor Torque Limit

Ask Questions
1

Hello all,

I am trying to write 55.0 to parID 248/249/348/349, but for some reason the parIDs are being limited to 50.8697. It should be limited to over 60 with this drive/motor combination.

Does anyone have a clue what else could be limiting the motor torque?

I am writing to the motor via an exclusive test window.

Relevant info:
Motor: 8LSA57 (69 Nm peak, 1.63Nm/A torque constant)
Drive: 8BVI011 (15.1A rated, 37A peak)
750V DC bus w/ acopos multi
acp10/mapp V5.24.1

Specific Error:
ParId 248: CTRL Torque limiter: Maximum acceleration torque in positive direction
Warning 38001: Torque limiter: Limit value higher than maximum value
Info: Maximum value = 50.8697

2

Hello @c213227

synchronuous motors do have a lower torque constant above the stall torque/current.
See " TCTRANS_MODE = 0 (DEFAULT)":

Torque Calculation - Automation Help

image

The torque constant of 1.63 (MOTOR_TORQUE_STALL / MOTOR_CURR_STALL) for this motor is only valid in the continuous operation area. In the pulse operation area the torque constant gets lower and is MOTOR_TORQUE_MAX / MOTOR_CURR_MAX → 69 Nm / 52,6 A = ~1,312 Nm/A.

With that torque constant and the ACOPOS maximum current of 37,7 A you will reach ~49-50 Nm.

Best regards
Lukas

2 Likes