Bryant 187B - Manual (Page 11)

11
OAT Thermistor must be
locked in place with spherical
nib end facing towards the
front of the control box
Fig. 8 -- Outdoor Air Thermistor (OAT) Attachment
OCT Thermistor must be
secured tight on the liquid tube.
Fig. 9 -- Outdoor Coil Thermistor (OCT) Attachment
Table 6 – TROUBLESHOOTING
OPERATION FAULT
AMBER
LED
FLASH
CODE
POSSIBLE CAUSE AND ACTION
Standby – no call for unit op-
eration
None
On sol-
id, no
flash
Normal operation
Low---stage Cool/Heat Opera-
tion
None 1, pause Normal operation
High-stage Cool/Heat Opera-
tion
None 2, pause Normal operation
System Communications
Failure
16
Communication with user interface lost. Check wiring to User Interface, indoor
and outdoor units
Invalid Model Plug 25
Control does not detect a model plug or detects an 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 Open 32* Low pressure 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 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 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. Contac-
tor may be stuck open or there is a wiring error.
Low-stage Thermal Lockout 81
Thermal cutout occurs in three consecutive low/ high---stage cycles.
low---stage locked out for 4 hours or until 24v power recycled.
High-stage Thermal Lock-
out
82
Thermal cutout occurs in three consecutive high/low---stage 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 oper-
ation 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 oper-
ation 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.
187B
/180B