Installation guide

OPERATION
Standby- no call for unit operation
Low Stage Cool/Heat Operation
High Stage Cool/Heat Operation
Brown out protection is Disabled
Brown out protection is Active
FA U LT
None
None
None
None
None
System Communications
Failure
Invalid Model Plug
High Pressure
Switch Open
Low Pressure
Bwitch or Discharge Temp
Switch Open
Control Fault
Brown Out
(230 v)
No 230v at Unit
Outdoor Air Temp Sensor
Fault
Outdoor Coil Sensor Fault
Thermistors out
of range
Low Stage
Thermal Cutout
High Stage
Thermal Cutout
Contactor Shorted
No 230V at
Compressor
Low Stage Thermal
Lockout
High Stage Thermal
Lockout
Low Pressure Lockout
Table 6 - Status Codes
AMBER LED
Possible Cause and Action
FLASH CODE
On solid, no flash Normal operation
1, pause Normal operation
2, Pause Normal operation
5, pause User mode selection, see instructions for more detail
6, Pause User mode selection, see instructions for more detail
Communication with Observer Wall Control lost. Check wiring to
16
Observer Wall Control, indoor and outdoor units
Control does not detect a model plug or detects and invalid model
25
plug. Unit will not operate without correct model plug,
31" High pressure switch trip. Check refrigerant charge, outdoor fan
operation and coils for airflow restrictions.
32* Low pressure switch or discharge temperature switch trip. Check
refrigerant charge and indoor air flow
Outdoor unit control board has failed. Control board needs to be
45 replaced.
46 Line Voltage <187v for at least 4 seconds. Compressor and fan
operation not allowed until voltage > 190v. Verify line voltage.
There is not 230v at the contactor when indoor unit is powered and
47 cooling/heating demand exists. Verify the disconnect is closed and
230v wiring is connected to the unit.
Outdoor air sensor not reading or out of range. Ohm out sensor and
53
check wiring
Coil sensor not reading or out of range. Ohm out sensor and check
55
wiring
56 Improper relationship between coil sensor and outdoor air sensor.
Ohm out sensors and check wiring.
Compressor operation detected then disappears while low stage
71" demand exists. Possible causes are internal compressor overload trip
or start relay and capacitor held in circuit too long (if installed)
Compressor operation detected then disappears while high stage
72* demand exists. Possible causes are internal compressor overload trip
or start relay and capacitor held in circuit too long (if installed)
Compressor voltage sensed when no demand for compressor
73 operation exists. Contactor may be stuck closed or there is a wiring
error.
Compressor voltage not sensed when compressor should be starting.
74 Disconnect may be open or contactor may be stuck open or there is a
wiring error.
Thermal cutout occurs in three consecutive low/high cycles. Low stage
82
locked at for 4 hours or until 24v power recycled.
Thermal cutout occurs in three consecutive low/high cycles. High
82
stage locked out for 4 hours or until 24v power recycled.
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.
Lockout 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
THERMISTOR CURVE
90
I I I I
80 _ _ < I _ I
\ i i i i i
x: 'X I I I I
_60 ,_ _ I T I
3o t N.... I _ I
a:: 2O
""_-_._ I
to t P
o L J ] i L
O 20 40 60 80 100 120
(q 7.77) (-6.67) (4.44) (15.56) (26.67) (37.78) (48.89)
TEMPERATURE °F (°C)
428 01 1703 02 Specifications subject to change without notice. 15