Carrier 25HNA Infinity
Series Installation Instructions Manual page 18

OPERATION
Standby – no call for unit opera-
tion
Emergency Mode − Model 25HNA9
only
Low Stage Cool/Heat Operation
High Stage Cool/Heat Opera-
tion
*Sequence: Compressor contactor is de−energized and outdoor fan is energized for up to 15 minutes. If demand still exists, control will
energize compressor contactor after 15 minute delay. If fault is cleared, unit will resume operation. If fault still exists, fan shuts off, and error
code continues to flash. Control will attempt re−start every 15 minutes. Cycling low voltage defeats the 15 minute delay.
Table 7—TROUBLESHOOTING
AMBER
LED
FAULT
FLASH
CODE
On solid,
None
no flash
Standard Thermo- Rapid, con-
stat Control tinuous flash-
(25HNA9 only) ing
None 1, pause
None 2, pause
System Commu- 16
nications Failure
Invalid Model
25
Plug
High Pressure
31
Switch Open
Low Pressure
32
Switch Open
Control Fault 45
Brown Out (230
46
v)
No 230v at Unit 47
Outdoor Air
Temp Sensor 53
Fault
Outdoor Coil
55
Sensor Fault
Thermistors out
56
of range
Low Stage Ther-
71*
mal Cutout
High Stage Ther-
72*
mal Cutout
Contactor
73*
Shorted
No 230V at
Compressor
74
(25HNA9 Only)
Low Stage Did
Not Start
75
(25HNA6 Only)
Low Stage Did
Not Start 3 times 76
(25HNA6Only)
High Stage Did
Not Start 77
(25HNA6 Only)
High Stage Did
Not Start 3 times
78
(25HNA6 Only)
Low Stage Ther-
81
mal Lockout
High Stage Ther-
82
mal Lockout
Low−Pressure
83
Lockout
High−Pressure
84
Lockout
Low Contactor
Open
85
(25HNA6 Only)
High Contactor
Open 87
(25HNA6 Only)
POSSIBLE CAUSE AND ACTION
Normal operation
Unit being controlled by standard thermostat inputs instead of Infinity Con-
trol. Only high stage operation is available. This operating mode should be
used in emergency situations only.
Normal operation
Normal operation
Communication with User Interface lost. Check wiring to UI, indoor
and outdoor units
Control does not detect a model plug or detects an invalid model
plug. Unit will not operate without correct model plug.
High−pressure switch trip. Check refrigerant charge, outdoor fan
operation and coils for airflow restrictions.
Low−pressure switch trip. Check refrigerant charge and indoor air
flow.
Outdoor unit control board has failed. Control board needs to be
replaced.
Line voltage < 187v for at least 4 seconds. Compressor and fan
operation not allowed until voltage>190v. Verify line voltage.
There is no 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 sensor not reading or out of range. Ohm out sensor
and check wiring.
Coil sensor not reading or out of range. Ohm out sensor and check
wiring.
Improper relationship between coil sensor and outdoor air sensor.
Ohm out sensors and check wiring.
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).
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).
Compressor voltage sensed when no demand for compressor op-
eration exists. Contactor may be stuck closed or there is a wiring
error.
Compressor voltage not sensed when compressor should be start-
ing. Contactor may be stuck open or there is a wiring error.
Specified start voltage at VR terminal was not achieved in low stage.
Start relay was de−energized after 1 second.
For 3 consecutive low stage starts, the specified start voltage at VR
terminal was not achieved & start relay was de−energized. Low
stage locked out for 30 minutes.
Specified start voltage at VS terminal was not achieved in high
stage. Start relay was de−energized after 1 second.
For 3 consecutive high stage starts, the specified start voltage at VS
terminal was not achieved & start relay was de−energized. High
stage locked out for 30 minutes.
Thermal cutout occurs in three consecutive low/high stage cycles.
Low stage locked out for 4 hours or until 24v power recycled.
Thermal cutout occurs in three consecutive high/low stage cycles.
High stage locked out for 4 hours or until 24v power recycled.
Low pressure switch trip has occurred during 3 consecutive cycles.
Unit operation locked out for 4 hours or until 24v power recycled.
High pressure switch trip has occurred during 3 consecutive cycles.
Unit operation locked out for 4 hours or until 24v power recycled.
Compressor voltage not sensed when compressor should be start-
ing. Low stage contactor may be stuck open or there is a wiring
error.
Compressor voltage not sensed when compressor should be start-
ing. High stage contactor may be stuck open or there is a wiring
error.
18