Installation guide

Example: 3 short flashes followed by 2 long flashes indicates
a 32 code. Table 3 shows this to be low pressure switch
open.
Table 3 - Status Codes
AMBER LED
OPERATION FAULT Possible Cause and Action
FLASH CODE
Standby- no call
for unit operation None On solid, no flash Normal operation - with communicating Control
Standby - no call None Off Normal operation - No call for cooling with 2-wire connection or indoor unit not pow-
for unit operation ere&
Cooling Operation None 1, pause Normal operation
System Communications 16 Communication with wall control lost. Check wiring to wall control, indoor and outdoor
Failure units
High Pressure 31 High pressure switch trip. Check refrigerant charge, outdoor fan operation and coils
Switch Open for airflow restrictions.
Low Pressure
32 Low pressure switch trip. Check refrigerant charge and indoor air flow
Switch Open
Outdoor unit control board has failed. Control board needs to be replaced.
Control Fault 45
The control voltage is less than 15.5v for at least 4 seconds. Compressor and fan
Brown Out
46 operation not allowed until control voltage is a minimum of 17.5v. Verify control volt-
(24 v) age.
Outdoor Air Temp Sensor
Fault 53 Outdoor air sensor not reading or out of range. Ohm out sensor and check wiring
Outdoor Coil Sensor Fault 55 Coil sensor not reading or out of range. Ohm out sensor and check wiring
Thermistors out 56 Improper relationship between coil sensor and outdoor air sensor. Ohm out sensors
of range and check wiring.
Compressor voltage sensed after start-up, then absent for 10 consecutive seconds
while cooling demand exists. Possible causes are internal compressor overload trip or
Thermal Cutout 72 loss of high voltage to compressor without loss of control voltage. The control will
continue fan operation and wait 15 minutes to attempt a restart. Fault will clear when
restart is successful, or low voltage power is cycled.
Contactor Shorted 73 Compressor voltage sensed when no demand for compressor operation exists. Con-
tactor may be stuck closed or there is a wiring error.
No 230V at 74 Compressor voltage not sensed when compressor should be starting. Disconnect may
Compressor be open or contactor may be stuck open or there is a wiring error.
Thermal cutout occurs in three consecutive cycles. Unit operation locked out for 4
Thermal Lockout 82
hours or until 24v power recycled.
Low Pressure Lockout 83 Low pressure switch trip has occurred during 3 consecutive cycles. Unit operation
locked out for 4 hours or until 24v power recycled.
High Pressure 84 High pressure switch trip has occurred during 3 consecutive cycles. Unit operation
Lockout locked out for 4 hours or until 24v power recycled.
Figure 8
1
Resistance vs Temperature Chart
90
80
_ 7o
_ 6o
6o
_ 4o
_ 3o
cc 2o
1o
o
(-17.77)
THERMISTOR CURVE
20 40 60 80 100 120
(-6.67) (4.44) (15.56) (26.67) (37.78) (48.89)
TEMPERATURE °F (°C)
421 01 5104 03 specificationssubjectto changewithout notice. 9