Control Word Timeout (X) (X); Start Failed; Internal Fan Fault; Brake Resistor Power Limit (X) (X) - Danfoss VLT FC 102 Series Design Manual

General Specifications and ...
WARNING/ALARM 17, Control word timeout
There is no communication to the adjustable frequency
drive.
The warning is only active when 8-04 Control Word Timeout
Function is NOT set to [0] Off.
If 8-04 Control Word Timeout Function is set to [5] Stop and
Trip, a warning appears and the adjustable frequency drive
ramps down until it stops then displays an alarm.
Troubleshooting
Check connections on the serial communication
cable.
Increase 8-03 Control Word Timeout Time
Check the operation of the communication
equipment.
Verify a proper installation based on EMC
requirements.
ALARM 18, Start failed
The speed has not been able to exceed 1-77 Compressor
Start Max Speed [RPM] during start within the allowed time.
(set in 1-79 Compressor Start Max Time to Trip). This may be
caused by a blocked motor.
WARNING 23, Internal fan fault
The fan warning function is an extra protective function
that checks if the fan is running/mounted. The fan warning
can be disabled in 14-53 Fan Monitor ([0] Disabled).
For the D, E, and F Frame filters, the regulated voltage to
the fans is monitored.
Troubleshooting
Check for proper fan operation.
Cycle power to the adjustable frequency drive
and check that the fan operates briefly at start-
up.
Check the sensors on the heatsink and control
card.
WARNING 24, External fan fault
The fan warning function is an extra protective function
that checks if the fan is running/mounted. The fan warning
can be disabled in 14-53 Fan Monitor ([0] Disabled).
Troubleshooting
Check for proper fan operation.
Cycle power to the adjustable frequency drive
and check that the fan operates briefly at start-
up.
Check the sensors on the heatsink and control
card.
MG11BC22
Design Guide
WARNING 25, Brake resistor short-circuit
The brake resistor is monitored during operation. If a short
circuit occurs, the brake function is disabled and the
warning appears. The adjustable frequency drive is still
operational but without the brake function. Remove power
to the adjustable frequency drive and replace the brake
resistor (see 2-15 Brake Check).
WARNING/ALARM 26, Brake resistor power limit
The power transmitted to the brake resistor is calculated as
a mean value over the last 120 seconds of run time. The
calculation is based on the intermediate circuit voltage and
the brake resistance value set in 2-16 AC Brake Max.
Current. The warning is active when the dissipated braking
energy is higher than 90% of the brake resistance power. If
[2] Trip is selected in 2-13 Brake Power Monitoring, the
adjustable frequency drive trips when the dissipated
braking energy reaches 100%.
WARNING/ALARM 27, Brake chopper fault
The brake transistor is monitored during operation and if a
short circuit occurs, the brake function is disabled and a
warning is issued. The adjustable frequency drive is still
operational but, since the brake transistor has short-
circuited, substantial power is transmitted to the brake
resistor, even if it is inactive.
Remove power to the adjustable frequency drive and
remove the brake resistor.
WARNING/ALARM 28, Brake check failed
The brake resistor is not connected or not working.
Check 2-15 Brake Check.
ALARM 29, Heatsink temp
The maximum temperature of the heatsink has been
exceeded. The temperature fault does not reset until the
temperature falls below a defined heatsink temperature.
The trip and reset points are different based on the
adjustable frequency drive power size.
Troubleshooting
Check for the following conditions.
Danfoss A/S © Rev. 06/2014 All rights reserved.
Ambient temperature too high.
Motor cable too long.
Incorrect airflow clearance above and below the
adjustable frequency drive.
Blocked airflow around the adjustable frequency
drive.
Damaged heatsink fan.
Dirty heatsink.
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