Rockwell Automation 592- E300 Overload Relay User Manual - Manual (Page 96)

96 Rockwell Automation Publication 193-UM015B-EN-P - June 2014
Chapter 5 Protective Trip and Warning Functions
Stall Protection
A motor stalls when its inrush current lasts for a longer than normal period of
time during its starting sequence. As a result, the motor heats up very rapidly and
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. The E300 Electronic Overload Relay can
monitor for this condition with its Stall Trip function and stop the motor before
damage and loss of production can occur.
Stall Trip
The E300 Electronic Overload Relay will trip with a Stall Trip indication when:
• No trip currently exists
• Stall protection is enabled
• Current is present
• The maximum phase current is greater than the Stall Trip Level for a time
period greater than the Stall Enabled Time
If the E300 Electronic Overload Relay trips on a stall, the:
• TRIP/WARN LED status indicator will flash a red 4-short blink pattern
• Bit 3 in Current Trip Status Parameter 4) will set to 1
• Bit 0 in Device Status 0 (Parameter 20) will set to 1
• Any relay outputs configured as a Trip Relay will open
• Any relay outputs configured as a Control Relay will open
• Any relay outputs configured as a Trip Alarm will close
• Any relay outputs configured as a Normal Relay will be placed in their
Protection Fault state (if so programmed)