Alarm 95, Broken Belt; Alarm 99, Locked Rotor; Alarm 126, Motor Rotating; Warning 127, Back Emf Too High - Danfoss VLT Midi Drive FC 280 Programming Manual

Troubleshooting

ALARM 95, Broken belt

Torque is below the torque level set for no load, indicating
a broken belt. Parameter 22-60 Broken Belt Function is set
for alarm.
Troubleshooting
•
Troubleshoot the system and reset the frequency
converter after clearing the fault.

ALARM 99, Locked rotor

The rotor is blocked. It is only enabled for PM motor
control.
Troubleshooting
•
Check if the motor shaft is locked.
•
Check if the start current triggers the current limit
set in parameter 4-18 Current Limit.
•
Check if it increases the value in
parameter 30-23 Locked Rotor Detection Time [s].

ALARM 126, Motor rotating

During AMA start-up, the motor is rotating. It is only valid
for PM motor.
Troubleshooting
•
Check if the motor is rotating before starting
AMA.

WARNING 127, Back EMF too high

This warning applies to PM motors only. When the back
EMF exceeds 90% x U (overvoltage threshold), and
invmax
does not drop to normal level within 5 s, this warning is
reported. The warning remains until the back EMF returns
to a normal level.
ALARM 188, STO function fault
24 V DC supply is connected to only 1 of the 2 STO
terminals (37 and 38), or a failure in STO channels is
detected. Make sure that both terminals are connected to
24 V DC supply, and the discrepancy between the signals
at the 2 terminals is less than 12 ms. If the fault still occurs,
contact the local Danfoss supplier.
MG07C302
Programming Guide
Danfoss A/S © 07/2016 All rights reserved.
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