Single-Stage Communicating Heat Pump System Functions And Sequence Of Operation; Sequence Of Operation - 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
Single-Stage Communicating Heat Pump
System Functions and Sequence of Operation
The outdoor unit control system has special functions. The following is
an overview of the control functions.

Sequence of Operation

Cooling & Heating Operation
This product utilizes either a standard indoor thermostat or Evolution
communication User Interface. With a call for cooling, the outdoor fan,
reversing valve, and compressor are energized. When the cooling
demand is satisfied, the compressor and fan will shut off. The reversing
valve will remain energized until the control board power is removed or
a call for heating is initiated.
NOTE: The outdoor fan motor will continue to operate for one minute
after compressor shuts off, when the outdoor ambient is greater than or
equal to 100°F/37.78°C.
With a call for heating, the outdoor fan and compressor are energized.
The reversing valve is de–energized in the heating mode.
Communication and Status Function Lights
Green Communications (COMM) Light (Evolution Control only)
A green LED (COMM light) on the outdoor board (see
successful communication with the other system products. The green
LED will remain OFF until communications is established. Once a valid
command is received, the green LED will turn ON continuously. If no
communication is received within 2 minutes, the LED will be turned
OFF until the next valid communication.
Fig. 39 – Control Board
Amber Status Light
An amber colored STATUS light is used to display the operation mode
and fault codes as specified in the troubleshooting section. See
for codes and definitions.
NOTE: Only one fault code will be displayed on the outdoor unit
control board (the most recent, with the highest priority).
Crankcase Heater Operation
The crankcase heater (when applicable) is energized during the off cycle
below 65°F/18.33°C.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Outdoor Fan Motor Operation
The outdoor unit control energizes outdoor fan any time the compressor
is operating (except defrost and intermittently during low ambient
cooling). The outdoor fan remains energized for 15 minutes if a pressure
switch or compressor thermal protector should open. Outdoor fan motor
will continue to operate for one minute after the compressor shuts off
when the outdoor ambient is greater than or equal to 100_F/37.78_C.
Time Delays
The unit time delays include:
• Five minute time delay to start cooling or heating operation when
there is a call from the thermostat or user interface (To bypass this
feature in a non–communicating system, momentarily short and
release forced defrost pins, in a communicating system push the UI
fan and up buttons simultaneously for approximately 10 seconds)
• Five minute compressor recycle delay on return from a brown out
condition
• Two minute time delay to return to standby operation from last
valid communication (with Evolution only)
• One minute time delay of outdoor fan at termination of cooling
mode when outdoor ambient is greater than or equal to
100_F/37.78_C.
Fig. 39) indicates
• Fifteen second delay at termination of defrost before the auxiliary
heat (W2) is de–energized
• Twenty second delay at termination of defrost before the outdoor
fan is energized
• Seventy and sixty second compressor delays when Quiet Shift–2
enabled
A210751
Table 14
47