INSTALLATION INSTRUCTIONS
R
−
410A Split System Heat Pumps
428 01 1703 01
15
Specifications subject to change without notice.
Table 6
−
Status Codes
OPERATION
FAULT
AMBER LED
FLASH CODE
Possible Cause and Action
Standby – no call for unit operation
None
On solid, no flash
Normal operation
Low Stage Cool/Heat Operation
None
1, pause
Normal operation
High Stage Cool/Heat Operation
None
2, Pause
Normal operation
Brown out protection is Disabled
None
5, pause
User mode selection, see instructions for more detail
Brown out protection is Active
None
6, Pause
User mode selection, see instructions for more detail
System Communications
Failure
16
Communication with Observer Wall Control lost. Check wiring to
Observer Wall Control, indoor and outdoor units
Invalid Model Plug
25
Control does not detect a model plug or detects and invalid model
plug. Unit will not operate without correct model plug.
High Pressure
Switch Open
31*
High pressure switch trip. Check refrigerant charge, outdoor fan
operation and coils for airflow restrictions.
Low Pressure
Switch or Discharge Temp
Switch Open
32*
Low pressure switch or discharge temperature switch trip. Check
refrigerant charge and indoor air flow
Control Fault
45
Outdoor unit control board has failed. Control board needs to be
replaced.
Brown Out
(230 v)
46
Line Voltage <187v for at least 4 seconds. Compressor and fan
operation not allowed until voltage > 190v. Verify line voltage.
No 230v at Unit
47
There is not 230v at the contactor when indoor unit is powered and
cooling/heating demand exists. Verify the disconnect is closed and
230v wiring is connected to the unit.
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
of range
56
Improper relationship between coil sensor and outdoor air sensor.
Ohm out sensors and check wiring.
Low Stage
Thermal Cutout
71*
Compressor operation detected then disappears while low stage
demand exists. Possible causes are internal compressor overload trip
or start relay and capacitor held in circuit too long (if installed)
High Stage
Thermal Cutout
72*
Compressor operation detected then disappears while high stage
demand exists. Possible causes are internal compressor overload trip
or start relay and capacitor held in circuit too long (if installed)
Contactor Shorted
73
Compressor voltage sensed when no demand for compressor
operation exists. Contactor may be stuck closed or there is a wiring
error.
No 230V at
Compressor
74
Compressor voltage not sensed when compressor should be starting.
Disconnect may be open or contactor may be stuck open or there is a
wiring error.
Low Stage Thermal
Lockout
82
Thermal cutout occurs in three consecutive low/high cycles. Low stage
locked at for 4 hours or until 24v power recycled.
High Stage Thermal
Lockout
82
Thermal cutout occurs in three consecutive low/high cycles. High
stage locked out for 4 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
Lockout
84
High pressure switch trip has occurred during 3 consecutive cycles.
Unit operation locked out for 4 hours or until 24v power recycled.
*Sequence: Compressor contactor is de
−
energized and outdoor fan is energized for up to 15 minutes. If demand still exists, control will energize compressor.
Figure 15
Resistance vs Temperature Chart
0
10
20
30
40
50
60
70
80
90
0
(-17.77)
20
(-6.67)
40
(4.44)
60
(15.56)
80
(26.67)
100
(37.78)
120
(48.89)
TEMPERATURE °F (°C)
RESISTANCE (KOHMS)
THERMISTOR CURVE
