Carrier 040-420 - Manual (Page 52)

Possible causes of fault are low refrigerant charge, plugged
filter drier, or a faulty EXV or thermistor.
Code 48
Low suction superheat, Circuit A
Code 49 Low suction superheat, Circuit B
If EXV is at minimum position, suction superheat is less
than F (5.5” C) or saturated evaporator temperature is
greater than MOP (maximum operating pressure) for more
than 5 minutes, affected circuit shuts down after going through
process, Reset is manual with
STOP-CCN switch, and start-up follows normal sequence.
Possible causes of fault are faulty EXV or thermistor.
Code 50 Illegal configuration
This fault indicates a configuration error. Unit is not al-
lowed to start. Check all configuration data and set points
and correct any errors.
Code 51
Initial configuration required
This fault indicates factory configuration has not been
done, and unit is not allowed to start. Refer to unit wiring
label diagrams for factory configuration codes, There are 8
groups of S-digit numbers that must be entered. The first
groups must be entered under s u b f u n c t i o n . G r o u p s
7 and 8 must be entered under s u b f u n c t i o n .
Enter each group, then press the key. Use the
down arrow after each group to bring up the next
empty screen. Unit should start after factory and field con-
figurations are correctly entered.
The usual cause of this fault is replacement of the pro-
cessor module. Refer to instructions accompanying the re-
placement module.
Code 52
Emergency stop by CCN command.
Unit goes through normal shutdown when this command
is received, and goes through normal start-up when
mand is cancelled.
S T A N D A R D : 040-060 50 H z
040-070 60 H z
- - - - I - - - - - -
,
C R ’ S
LEGEND
S T A N D A R D : 070 50
A C C E S S O R Y : 040-060 50 H z 040-070 60 H z
C O M M
CR
D G T
HPS
PWR
SNB
TRAN
U
Fig. 24-V Safety Circuit Wiring (040-070)
52
Contactor
Circuit Breaker
Communications Bus
Compressor Protection
Control Module
Compressor Contactor Relay
Discharge Gas Thermostat (Optional)
Relay Module (Low Voltage)
High-Pressure Switch
Low
P l u g
P o w e r
S n u b b e r
T e r m i n a l B l o c k
Transformer
Unloader