Rockwell Automation 825 Smart Motor Manager User Manual - Manual (Page 124)

6-5 Commissioning and Operation
Publication 825-UM001B-EN-P January 2001
• Setting locked rotor time to a minimum level
This procedure enables you to set the locked rotor time to a minimum, so that the
motor and installation are better protected.
a. Choose a locked rotor time that is less than the probable starting time (e.g., 2 s for
thermally rapid underwater motors).
b. Start the motor and allow it to cool down after a thermal trip.
c. Increase the locked-rotor time until starting succeeds reliably.
• Setting the locked rotor time when the motor starting time is known:
EXAMPLE
Known starting time of the motor is t
A
= 15 sec.
Locked-rotor time to be set:
approximately
Setting the locked rotor time with the aid of the indication of thermal utilization
Basic Unit “ACTUAL VALUES” display
LCD:
Set the locked rotor time so that the current converter does not trip (< 100%) with the least
favorable service load, e.g., at the end of a heavy start. Note that for this procedure, the motor
must be of adequate size for the intended application.
Programming, Setup, and Operation
During programming, setup, and operation, the actual operational values can be continuously
monitored. To do this, switch the display to “Actual Values” (refer to
Chapter 3 ).
Starting
LCD Operation Description
Motor
start
The motor current, depending on the type of motor,
must drop from about 400…800%
,
e
to the service
current of 100% ,
e
.
W
A
1.4
----- 15
1.4
------- 11
V
= =
TH UTILIZ 00 %
I MOTOR 00 % Ie