Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control User Manual

Page 439

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Troubleshooting

7-17

7000 “B” Frame

7000-UM150I-EN-P – June 2013

FAULT

MESSAGE

FAULT

CODE

DESCRIPTION

RECOMMENDED ACTIONS

Motor Overspeed

The motor Speed Feedback (P289) has
exceeded Motor Overspeed Trip (P185) for
the duration set in Motor Overspeed Delay

(P186).

– Check for unbalance on the motor and

line feedback voltages

– Improper Settings – Check parameter

settings for Reference Command

Maximum and Ensure it is not too close
to Overspeed Trip increase

– Adjust Speed Regulator Bandwidth to

control overshoot, and ensure
acceleration rate near maximum speed is
not too great

– Check for load transients
– For Tachometers, ensure the ppr is set

properly and the feedback is valid

– Check tachometer pulse train with an

oscilloscope

Motor Protection

138

Standard External Fault/Warning Input
included to allow the end-user to install a

protective relay (IE Bulletin 825 Motor
Protection Relay) auxiliary contact that can
activate a drive fault or warning, depending

on configuration of Motor Prot Class (P443).

– Check device responsible for the

auxiliary contact to this input and
investigate the fault indicated by the
device‟s fault message

– Investigate internal and external causes

for this fault code

– Check the 120V signal through the

external device

– Check the XIO board inputs and

parameter status bits

Motor Stall

The drive has detected a motor stall
condition, with a delay set by Motor Stall
Delay (P191). The different methods of

Motor Stall detection depend on whether a
tachometer/encoder is installed or not.
Sensorless faults involve the motor not

building up enough flux feedback to be
detected by the drive, while tachometer
feedback methods look at the difference

between the tachometer/encoder feedback
and the speed command.

Possible Causes:
– Insufficient torque on starting– Increase

Torque Command 0 and 1 to avoid motor
stalls when starting if Speed Feedback

Mode is Sensorless

– Insufficient torque – Increase Torque

Limit Motoring to avoid motor stalls while
running

– Reverse Load Rotation – Ensure the

load is not rotating in the opposite
direction

– Increase motor stall delay
– Ensure Tachometer Feedback is

functional where applicable

– Ensure the motor is not spinning forward

at a speed greater than Reference
Command

Motor ADC_DAC