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Possible cause/Suggested solution
Heatsink Overtemp
Check if cooling fans are operating. If mounted in an enclosure, check if ventilation is adequate.
Fans operate during Start, Run and for 10 minutes after the starter exits the Stop state.
NOTE
Models MCD5-0021B to MCD4-0053B and MCD5-0141B do not have a cooling fan.
Models with fans will operate the cooling fans from a Start until 10 minutes after a
Stop.
Related Parameters:
16-6 Heatsink Overtemp
Input A Trip
Identify and resolve the condition which caused Input A to activate.
Related Parameters: 3-3, 3-4, 3-5, 3-6, 3-7, and 16-8
Inst Overcurrent
The motor has experienced a sharp rise in motor current, probably caused by a locked rotor
condition (shearpin) while running. This may indicate a jammed load.
Related Parameters: 2-6, 2-7, and 16-4
Internal Fault X
The MCD 500 has tripped on an internal fault. Contact your local supplier with the fault code (X).
Related Parameters.: None
L1 Phase Loss
L2 Phase Loss
L3 Phase Loss
During prestart checks the starter has detected a phase loss as indicated.
In run state, the starter has detected that the current on the affected phase has dropped below
3.3% of the programmed motor FLC for more than 1 second, indicating that either the incoming
phase or connection to the motor has been lost.
Check the supply and the input and output connections at the starter and at the motor end.
Phase loss can also be caused by a failed SCR, particularly an SCR that has failed open circuit. A
failed SCR can only be definitely diagnosed by replacing the SCR and checking the starter's
performance.
Related Parameters: None
L1-T1 Shorted
L2-T2 Shorted
L3-T3 Shorted
During prestart checks the starter has detected a shorted SCR or a short within the bypass
contactor as indicated.
Related Parameters: none
Low Control Volts
The MCD 500 has detected a drop in the control voltage.
•
Check the external control supply (terminals A4, A5, A6) and reset the starter.
If the external control supply is stable:
•
the 24 V supply on the main control PCB may be faulty; or
•
the bypass driver PCB may be faulty (internally bypassed models only).
This protection is not active in Ready state.
Related Parameters:
16-13 Low Control Volts
Motor Overload/
Motor 2 Overlaod
The motor has reached its maximum thermal capacity. Overload can be caused by:
- The soft starter protection settings not matching the motor thermal capacity.
- Excessive starts per hour
- Excessive throughput
- Damage to the motor windings.
Resolve the cause of the overload and allow the motor to cool.
Related Parameters: 1-1, 1-2, 1-3, 1-4, 7-1, 7-2, 7-3, 7-4, and 16-1
Motor Connection
The motor is not connected correctly to the soft starter for inline or inside delta use.
- Check individual motor connections to the soft starter for power circuit continuity.
- Check connections at the motor terminal box.
Related Parameters:
15-7 Motor Connection
Troubleshooting
MCD 500 Operating Instruction
MG17K402 - VLT
®
is a registered Danfoss trademark
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