Rockwell Automation 825 Smart Motor Manager User Manual - Manual (Page 67)

Functions 3-34
Publication 825-UM001B-EN-P January 2001
Monitoring the Starting Time
Function
The starting time of the motor is monitored. If starting has not finished by the set time, the
installation can be switched off. This monitoring is independent of the thermal state of the
motor.
The beginning of a start is recognized by the Smart Motor Manager when the motor current
reaches 1.2
,
e
. Starting is deemed to have been completed when the motor current is less than
1.1 ,
e
.
Applications
• Installations in which an elevated load or stalling of the drive have to be detected
during the starting stage, in order to avoid serious damage. Possible causes:
overloaded installation, defective bearings, or transmission elements.
Figure 3.22 Monitoring Starting Time
1 Motor starting current ≥ 1.2 ,
e
2 Rated conditions
t
V
Max. starting time
3 Tripping if starting lasts too long
t v
≤ 1.1 I e
1
2
3
t
≥ 1.2 I e
I