Rockwell Automation 193-EC1_2_3_5, 193-ECPM,592-EC1_2_3_5 E3 and E3 Plus Solid-State Overload Relay User Manual - Manual (Page 56)

56 Rockwell Automation Publication 193-UM002I-EN-P - December 2011
Chapter 3 Protective Trip & Warning Functions
Stall Protection
When a motor stalls during its starting sequence, the motor heats up very rapidly.
After the permissible stalling time, the motor reaches the temperature limit of its
insulation. Rapid stall detection during the starting sequence can extend the
motor’s life, as well as minimize potential damage and loss of production.
Stall Time
The E3 Overload Relay will trip with a stall indication when:
• no trip currently exists,
• stall protection is enabled, and
• the maximum phase current is greater than the Stall Trip Level for a time
period greater than the Stall Enabled Time.
If the E3 Overload Relay trips on a stall, the:
• TRIP/WARN LED status indicator will flash a red 5-blink pattern,
• bit 4 in Trip Status, Parameter 14, will set to 1,
• bit 0 in Device Status, Parameter 21, will set to 1
• Trip Relay contacts will open, and
• outputs will be placed in their Protection Fault state (if so programmed).
Stall Enabled Time, Parameter 39, allows the installer to adjust the time the E3
Overload Relay monitors for a stall condition during the motor starting sequence
and is adjustable from 0…250 seconds.
Stall Trip Level, Parameter 40, allows the installer to define the locked rotor
current and is adjustable from 100…600% of the FLA Setting, Parameter 28.
IMPORTANT The Protection Fault State of OUT A and OUT B is defined by:
• OUTA Pr FltState, Parameter 65
• OUTA Pr FltValue, Parameter 66
• OUTB Pr FltState, Parameter 71
• OUTB Pr FltValue, Parameter 72
IMPORTANT Stall Protection is only enabled during the motor starting sequence. If the
maximum phase of load current falls below the programmed Stall Trip
Level before the Stall Enabled Time elapses, the E3 Overload Relay
disables Stall Protection until the next motor starting sequence.
IMPORTANT The E3 Overload Relay considers a motor to have begun its starting
sequence if the maximum phase of motor current transitions from 0 A to
approximately 30% of the minimum FLA Setting.