Liquid Line Solenoid Accessory; Major Components; Troubleshooting; Systems Communication Failure - Bryant Base Series Application Manual And Service Manual

Residential Air Conditioners and Heat Pumps Using R-22 and Puron® Refrigerant: Application Guideline and Service Manual
seconds. During this 70 second compressor off time, the reversing valve
will be energized. Once the 70 second compressor off time has been
reached, the compressor will be energized then the outdoor fan will be
de–energized at which time the normal defrost cycle begins. Defrost
Termination – the outdoor fan will be energized shortly before the
compressor is de–energized for 60 seconds. During the compressor 60
second off time, the reversing valve will be de–energized. Once the 60
second compressor off time has been completed, the compressor will be
energized at which time the system will be in normal heat mode.

LIQUID LINE SOLENOID ACCESSORY

In heat pump long line applications, a liquid line solenoid is required to
control refrigerant migration in the heating mode. The solenoid should
be installed near the outdoor unit with the arrow facing the outdoor unit.
This is the direction of flow control. See Long Line Application
Guideline for details.
Accessory Liquid Solenoid with Evolution Communicating Control:
When using the Evolution Control, a liquid line solenoid output labeled
LS is provided. Connect the solenoid as shown in the wiring label
diagram. This is a 24vac output that is energized whenever the
compressor is energized. It closes in the compressor–off mode to prevent
refrigerant migration into the unit through the liquid line.
Accessory Liquid Solenoid with Non–Communicating Thermostat: The
liquid solenoid is connected to the Y and C terminal connections. The
liquid solenoid closes in the compressor–off mode to prevent refrigerant
migration into the unit through the liquid line.

MAJOR COMPONENTS

Control Board
The Heat Pump control board controls the following functions:
• Compressor contactor operation
• Outdoor fan motor operation
• Reversing valve operation
• Defrost operation
• Compressor external protection
• Pressure switch monitoring
• Time delays
Field Connections
When using Evolution communicating control, 4 field wires are required
to be connected to the factory wires already wired to the ABCD terminal
(see Fig. 11). Unit as provided by manufacturer is set up for Evolution
communicating control.
When used with a standard non–communicating thermostat,5 field wires
are required to be connected to R, Y, W2, O and C. Disconnect factory
provided wires from A, B, C, and D terminals. Using factory provided
wires, connect to R, Y, W2, O and C terminals on the control board.
Connect field 24V wires to factory provided wires now connected to R,
Y, W2, O and C and cap both sides or remove unused factory provided
wires.
On Evolution only, the 24vac LS (liquid solenoid) output terminal is
energized for the liquid solenoid accessory. the connection is located at
the side of the control board just below the ABCD Evolution connector.
Compressor Internal Relief
The compressor is protected by an internal pressure relief (IPR) which
relieves discharge gas into the compressor shell when differential
between suction and discharge pressure exceeds 550–625 psig. The
compressor is also protected by an internal overload attached to motor
windings.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.

TROUBLESHOOTING

Systems Communication Failure

If communication between User Interface (UI), and condensing unit is
lost, the outdoor control will flash the appropriate fault code. (See
Table 14) Check the wiring to the UI, indoor and outdoor units.

Pressure Switch Protection

The outdoor unit is equipped with high– and low–pressure switches. If
the control senses the opening of a high or low–pressure switch, it will
de–energize the compressor contactor, keep the outdoor fan operating
for 15 minutes and display the appropriate fault code. (See table 14)
After a 15 minute delay, if there is still a call for cooling, and the LPS or
HPS is reset, the compressor contactor is energized. If the LPS or HPS
has not closed after a 15 minute delay, the outdoor fan is turned off. If
the open switch closes anytime after the 15–minute delay, then the unit
will resume operation with a call for cooling.
If the LPS or HPS trips for five consecutive cycles, then unit operation is
locked out for 4 hours and the appropriate fault code (See
displayed.
In the event of a high–pressure switch trip or high–pressure lockout,
check the refrigerant charge, outdoor fan operation and outdoor coil (in
cooling) for airflow restrictions, or indoor airflow in heating.
In the event of a low–pressure switch trip or low–pressure lockout,
check the refrigerant charge and indoor airflow (cooling) and outdoor
fan operation and outdoor coil in heating.

Control Fault

If the outdoor unit control board has failed, the control will flash the
appropriate fault code. (See
replaced.

24V Brown Out Protection

If the control voltage is less than 15.5volts for at least 4 seconds, the
compressor contactor and fan relay are de–energized. Compressor and
fan operation are not allowed until control voltage is a minimum of
17.5volts. The control will flash the appropriate fault code. (See
Table 14) Verify the control voltage is in the allowable range of 18–
30volts.

Compressor Voltage Sensing

The input terminals labeled VR and VS on the control board (see
Fig. 11) are used to detect compressor voltage status, and alert the user
of potential problems. The control continuously monitors the high
voltage on the run capacitor of the compressor motor. Voltage should be
present any time the compressor contactor is energized, and voltage
should not be present when the contactor is de–energized.
Compressor Thermal Cutout
or Loss of 230V Power
If the control senses the compressor voltage after start–up, and is then
absent for 10 consecutive seconds while cooling demand exists, it will
de–energize the compressor contactor, keep the outdoor fan operating
for 15 minutes (if 230v power present) and display the appropriate fault
code. (See Table 14) Possible causes are compressor internal overload
trip or loss of high voltage (230V) to compressor without loss of control
voltage.
After a 15 minute delay, if there is still a call for cooling, the compressor
contactor is energized. If the thermal protector has not re–set, the
outdoor fan is turned off. If the call for cooling continues, the control
will energize the compressor contactor every 15 minutes. If the thermal
protector closes, (at the next 15 minute interval check), the unit will
resume operation.
If the thermal cutout trips for three consecutive cycles, then unit
operation is locked out for 4 hours and the appropriate fault code (See
Table 14) is displayed.
49
Table
Table 14) The control board should be
14) is