Parameter and variable descriptions 6-47 – Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE User Manual
Page 103

PARAMETER AND VARIABLE DESCRIPTIONS
6-47
1557-UM050F-EN-P – June 2013
V Stator [V stator]
Linear number:
344
Minimum value:
0.000 pu
Maximum value:
1.500 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the calculated stator voltage magnitude. It varies with both speed and torque and if the flux
command is set correctly should be about 1.0 pu at rated speed and rated load. The stator voltage may be
less than 1.0 pu at rated speed if the load torque is less than rated or the line voltage is low.
Torque [Torque]
Linear number:
345
Minimum value:
-1.500
Maximum value:
1.500
Analog Output Scaling: 5.0 V = 1.0
This variable is the calculated motor torque. A value of 1.000 corresponds to rated torque. It is positive for
forward torque and negative for reverse torque.
Prior to Rev 4.60/5.00, this variable was scaled in per unit based on the motor rated kVA and was about 10%
lower.
Motor Power [Motor power]
Linear number:
346
Minimum value:
-1.500
Maximum value:
1.500
Analog Output Scaling: 5.0 V = 1.0
This variable is the calculated motor power. A value of 1.000 corresponds to rated power. It is positive for
motoring and negative for generating regardless of the direction of rotation.
Prior to Rev 4.60/5.00, this variable was scaled in per unit based on the motor rated kVA and was about 10%
lower.
V Neutral Motor [V neutral motor]
Linear number:
347
Minimum value:
0.000 pu
Maximum value:
1.500 pu
Analog Output Scaling: 5.0 V = 1.0 pu
This variable is the measured motor neutral to ground voltage.
Tachometer Feedback [Tach feedback]
Linear number:
348
Minimum value:
-100.0 Hz
Maximum value:
100.0 Hz
Analog Output Scaling: 1.0 V = 12.8 Hz
This variable is the motor speed measured using the optional tachometer or encoder. It is positive for forward
rotation and negative for reverse rotation.