Rockwell Automation 592- E300 Overload Relay User Manual - Manual (Page 320)

320 Rockwell Automation Publication 193-UM015B-EN-P - June 2014
Chapter 10 Troubleshooting
• Setting Overload Reset Mode (Parameter 173) to “Automatic” to allow the
unit to automatically reset after an overload trip
• Setting Trip Reset (Parameter 163) to a value of 1, “Trip Reset”
Trip/Warn LED
Troubleshooting Procedures
IMPORTANT An overload trip cannot be reset until the value of Percent Thermal Capacity
Utilized (Parameter 1) is below the value set in Overload Reset Level
(Parameter 174).
Trip Description Possible Cause Corrective Action
Test Trip 1. Operation of the Test/Reset 1. Operate the Test/Reset button to clear
Overload
1. Motor overloaded 1. Check and correct source of overload (load,
mechanical transmission components, motor
bearings).
2. Improper parameter settings 2. Set parameter values to match the motor and
application requirements.
Phase Loss
1. Missing supply phase 1. Check for open line (i.e. blown fuse).
2. Poor electrical connection
2. Check all power terminations from the branch
circuit-protecting device down to the motor for
proper tightness. Ensure that the overload
connection to the contactor is secure.
3. Contactor operation 3. Inspect contactor for proper operation.
4. Improper parameter setting
4. Single-phase applications require that
Single/Three Phase (Parameter 176) is set to
“single phase”.
Ground Fault
1. Power conductor or motor winding is
shorting to ground 1. Check power conductors and motor windings
for low resistance to ground.
2. Motor winding insulation is decayed
2. Check motor winding insulation for low
resistance to ground.
3. Foreign Object short 3. Check for foreign objects.
4. External ground fault sensor (core balance
current transformer) has improper connection
4. Check cable connections.
Stall
1. Motor has not reached full speed by the end
of the Stall Enabld Time (Parameter 249) 1. Check for source of stall (i.e. excessive load, or
mechanical transmission component failure).
2. Improper parameter settings
2. Stall Enabled Time (Parameter 249) is set too
low for the application. Check to ensure that
FLA Setting (Parameter 171) is set correctly.
Jam
1. Motor current has exceeded the programmed
jam level
1. Check for the source of the jam (i.e., excessive
load or mechanical transmission component
failure).
2. Improper parameter settings
2. Jam Trip Level (Parameter 253) is set too low
for the application. Check to ensure that FLA
Setting (Parameter 171) is set correctly.
PTC
1. Motor stator windings overheated
1. Check for source of motor overtemperature
(i.e. overload, obstructed cooling, high ambient
temperature, excessive starts/hour).
2. Thermistor leads short-circuited or broken
2. Inspect thermistor leads for short-circuit or
open
Current Imbalance
1. Imbalance in incoming power 1. Check power system (i.e. blown fuse).
2. Motor winding imbalance
2. Repair motor, or if acceptable, raise value of
Current Imbalance Trip Level (Parameter 261),
CI Trip Level
3. Motor idling
3. Raise value of Current Imbalance Trip Level
(Parameter 261) to an acceptable level.
4. Contactor or circuit breaker operation
4. Inspect contactor and circuit breaker for
proper operation.