7. Troubleshooting
circuited, substantial power is transmitted to
the brake resistor, even if it is inactive.
Turn off the adjustable frequency drive and
remove the brake resistor.
ALARM/WARNING 28
Brake check failed:
Brake resistor fault: the brake resistor is not
connected/working.
ALARM 29
Adjustable frequency drive over-tem-
7
perature:
If the enclosure is IP 20 or IP 21/TYPE 1, the
cut-out temperature of the heatsink is 203
+9
o
[95
adjustable frequency drive. The temperature
fault cannot be reset until the temperature of
the heatsink is below 158
o
+5
C].
The fault could be a result of:
-
-
ALARM 30
Motor phase U missing:
Motor phase U between the adjustable fre-
quency drive and the motor is missing.
Turn off the adjustable frequency drive and
check motor phase U.
ALARM 31
Motor phase V missing:
Motor phase V between the adjustable fre-
quency drive and the motor is missing.
Turn off the adjustable frequency drive and
check motor phase V.
ALARM 32
Motor phase W missing:
Motor phase W between the adjustable fre-
quency drive and the motor is missing.
136
Warning: There is a risk of sub-
stantial power being transmit-
ted to the brake resistor if the
brake transistor is short-circuit-
ed.
o
C +5
o
C], depending on the size of the
o
o
C +5
Ambient temperature too high
Motor cable too long
MG.11.A4.22 - VLT
Turn off the adjustable frequency drive and
check motor phase W.
ALARM 33
Soft-charge fault:
Too many power-ups have occurred within a
short time period. See the chapter
tions
for the allowed number of power-ups
within one minute.
WARNING/ALARM 34
Ser. com. bus fault:
The serial communication bus on the commu-
nication option card is not working.
WARNING 35
Out of frequency range:
This warning is issued if the output frequency
has reached its W
Warning speed high
or
justable frequency drive is in P
o
F
closed-loop
(par. 1-00), the warning is active
in the display. If the adjustable frequency
drive is not in this mode, bit 008000 Out of
frequency range
o
F [70
C
active but there is no warning in the display.
ALARM 38
Internal fault:
Contact the local Danfoss supplier.
WARNING 47
24 V supply low:
The external 24 V DC back-up power supply
may be overloaded; otherwise, contact your
local Danfoss supplier.
WARNING 48
1.8 V supply low:
Contact the local Danfoss supplier.
ALARM 50
AMA calibration failed:
Contact the local Danfoss supplier.
ALARM 51
AMA check Unom and Inom:
The setting of motor voltage, motor current
and motor power is presumably wrong. Check
the settings.
®
is a registered Danfoss trademark
VLT
®
HVAC Drive Instruction Manual
Specifica-
arning speed low
(par. 4-52)
(par. 4-53). If the ad-
rocess control
,
in extended status word is