Danfoss VLT AHF 005 Programming Guide

If 8-04 Control Word Timeout Function is set to [5] Stop and
Trip, a warning appears and the frequency converter ramps
down until it stops, and then it displays an alarm.
Troubleshooting
•
Check the connections on the serial communi-
cation 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
parameter 1-77 Compressor Start Max Speed [RPM] during
start within the allowed time. (set in
parameter 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 frequency converters with DC fans, there is a feedback
sensor mounted in the fan. If the fan is commanded to run
and there is no feedback from the sensor, this alarm
appears. For frequency converters with AC fans, the
voltage to the fan is monitored.
Troubleshooting
•
Check for proper fan operation.
•
Cycle power to the frequency converter and
check that the fan operates
briey at start-up.
•
Check the sensors on the heat sink 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).
For frequency converters with DC fans, there is a feedback
sensor mounted in the fan. If the fan is commanded to run
and there is no feedback from the sensor, this alarm
appears. For frequency converters with AC fans, the
voltage to the fan is monitored.
Troubleshooting
•
Check for proper fan operation.
•
Cycle power to the frequency converter and
check that the fan operates briey at start-up.
•
Check the sensors on the heat sink and control
card.
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 frequency converter is still
operational, but without the brake function.
Troubleshooting
•
Remove the power to the frequency converter
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 s of run time. The
calculation is based on the DC-link voltage and the brake
resistor value set in 2-16 AC brake Max. Current. The
warning is active when the dissipated braking power is
higher than 90% of the brake resistor power. If option [2]
Trip is selected in 2-13 Brake Power Monitoring, the
frequency converter trips when the dissipated braking
power 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 frequency converter is still
operational but, since the brake transistor has short-
circuited, substantial power is transmitted to the brake
resistor, even if it is inactive.
Troubleshooting
•
Remove power to the frequency converter 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, Heat Sink temp
The maximum temperature of the heat sink has been
exceeded. The temperature fault does not reset until the
temperature drops below a dened heat sink temperature.
The trip and reset points are dierent based on the
frequency converter power size.
Troubleshooting
Check for the following conditions.
•
Ambient temperature too high.
•
Motor cables too long.
•
Incorrect airow clearance above and below the
frequency converter.
•
Blocked airow around the frequency converter.
•
Damaged heat sink fan.
•
Dirty heat sink.
ALARM 30, Motor phase U missing
Motor phase U between the frequency converter and the
motor is missing.
Troubleshooting
VLT
®
HVAC Drive FC 102
218 Danfoss A/S © 03/2015 All rights reserved. MG11CE02
44

Danfoss VLT AHF 005 Specifications

General

Brand	Danfoss
Model	VLT AHF 005
Category	DC Drives
Language	English