Rockwell Automation 1560E SMC Flex Smart Motor Controller - Manual (Page 23)

Product Overview 1-1
600%
Percent
Full Load
Current
Jam
Time (seconds)
Running
User Programmed
Trip Level
600%
Percent
Full Load
Current
Jam
Time (seconds)
Running
User Programmed
Trip Level
Figure 1.12 – Jam Detection :
:
Jam Detection is disabled during slow speed and braking operation.
Ground Fault
In isolated or high impedance-grounded systems, core-balanced current
sensors are typically used to detect low level ground faults caused by
insulation breakdowns or entry of foreign objects. Detection of such
ground faults can be used to interrupt the system to prevent further damage,
or to alert the appropriate personnel to perform timely maintenance.
The MV SMC-Flex’s ground fault detection capabilities consist of using a
core balance current transformer for 1 to 5A core-balanced ground fault
protection with the option of enabling Ground Fault Trip, Ground Fault
Alarm, or both (a core balance CT is provided with 1562E units).
Ground Fault Trip
The MV SMC-Flex will trip with a ground fault indication if:
• No trip currently exists
• Ground fault protection is enabled
• GF Inhibit Time has expired
• GF Current is equal to or greater than the GF Trip Level for a time
period greater than the GF Trip Delay
Parameter 75, Gnd Flt Inh Time, allows the installer to inhibit a ground
fault trip from occurring during the motor starting sequence and is
adjustable from 0 to 250 seconds.