Danfoss vlt soft starter mcd 500 - 10 Troubleshooting; Trip Messages

10 Troubleshooting
When a protection condition is detected, the VLT
®
Soft
Starter MCD 500 writes this condition to the event log and
may also trip or issue a warning. The soft starter response
depends on the protection action settings (parameter
group 16 Protection Actions).
Some protection responses cannot be adjusted. Usually,
external events (for example phase loss) or a fault within
the soft starter cause these trips. These trips do not have
associated parameters and cannot be set to Warn or Log.
If the soft starter trips:
1. Identify and clear the condition that triggered the
trip.
2. Reset the soft starter.
3. Restart the soft starter.
To reset the soft starter, press [Reset] or activate the Reset
remote input.
If the soft starter has issued a warning, it resets itself when
the cause of the warning has been resolved.
10.1 Trip Messages
Table 10.1 lists the protection mechanisms in the soft starter and the probable cause of the trip. Some of these protection
mechanisms can be adjusted using parameter group 2 Protection and parameter group 16 Protection Action. Other settings are
built-in system protections and cannot be set or adjusted.
Display Possible cause/Suggested solution
Awaiting data The LCP does not receive data from the control PCB. Check the cable connection and the tting of
the display on the soft starter.
Battery/clock A verication error has occurred on the real-time clock, or the back-up battery voltage is low. If
the battery is low and the power is o, date/time settings are lost. Reprogram the date and time.
Related parameter:
•
Parameter 16-12 Battery Clock.
Controller Name selected for a programmable input. Refer to Input A trip.
Current imbalance Problems with the motor, the environment, or the installation can cause current imbalance, such
as:
•
An imbalance in the incoming mains voltage.
•
A problem with the motor windings.
•
A light load on the motor.
•
A phase loss on mains terminals L1, L2, or L3 during run mode.
An SCR that has failed open circuit. A failed SCR can only be diagnosed accurately by replacing the
SCR and checking the soft starter performance.
Related parameters:
•
Parameter 2-2 Current Imbalance.
•
Parameter 2-3 Current Imbalance Delay.
•
Parameter 16-2 Current Imbalance.
Current read err lx Where X is 1, 2, or 3.
Internal fault (PCB fault). The output from the current transformer circuit is not close enough to 0
when the SCRs are turned o. Contact the local Danfoss supplier for advice.
This trip is not adjustable.
Related parameters: None.
Troubleshooting Operating Guide
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