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11

GENERAL SEQUENCE OF OPERATION

STANDARD THERMOSTAT

Turn on power to indoor and outdoor units. Transformer is

energized with power supplied.

Cooling

O n a c a l l f o r c o o l i n g , a s t a n d a r d t h e r m o s t a t

(non--communicating) makes circuits R--O and R--Y and R--G.

Circuit R--O energizes reversing valve, switching it to cooling
position. Circuit R--Y energizes contactor, starting outdoor fan

motor and compressor circuit. R--G energizes indoor unit blower
relay, starting indoor blower motor on high speed.
When a standard thermostat (non--communicating) is satisfied, its

contacts open, de--energizing contactor and blower relay.

Compressor and motors should stop.

NOTE

:

If indoor unit is equipped with a time--delay relay

circuit, the indoor blower will run an additional 90 seconds to
increase system efficiency.

Heating

On a call for heating a standard thermostat (non--communicating)

makes circuits R--Y and R--G. Circuit R--Y energizes contactor,
starting outdoor fan motor and compressor. Circuit R--G

energizes indoor blower relay, starting blower motor on high
speed.
Should temperature continue to fall, R--W2 is made through

second--stage room thermostat. Circuit R--W2 energizes a relay,

bringing on first bank of supplemental electric heat and providing
electrical potential to second heater relay (if used). If outdoor

temperature falls below setting of outdoor thermostat (factory
installed), contacts close to complete circuit and bring on second

bank of supplemental electric heat.
When thermostat is satisfied, its contacts open, de--energizing

contactor and relay. All heaters and motors should stop after all
fan off delays.

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

Infinity 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 deg F.
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

(Infinity Control only)

A green LED (COMM light) on the outdoor board (see Fig. 14)

indicates 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.

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 Table 3 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 deg F.

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 deg F.

25H

PA

Summary of Contents for 25HPA Performance Series

Page 1: ...ements 3 Step 4 Operating Ambient 3 Step 5 Elevate Unit 3 Step 6 Install TXV 3 4 Step 7 Make Piping Connections 5 7 Step 8 Make Electrical Connections 7 8 Step 9 Compressor Crankcase Heater 8 Step 10...

Page 2: ...h a suitable warning label INSTALLATION RECOMMENDATIONS NOTE In some cases noise in the living area has been traced to gas pulsations from improper installation of equipment 1 Locate unit away from wi...

Page 3: ...23 3 4 36 1 2 X 40 9 5 8 6 13 16 28 3 4 A05177 Fig 3 Tiedown Knockout Requirements On rooftop applications locate unit at least 6 in above roof surface STEP 4 Operating Ambient The minimum outdoor ope...

Page 4: ...R 22 Indoor Coil 1 Pump system down to 2 psig and recover refrigerant 2 Remove coil access panel and fitting panel from front of cabinet 3 Remove TXV support clamp using a 5 16 in nut driver Save the...

Page 5: ...or coil are exposed to atmosphere they must be evacuated to 500 microns to eliminate contamination and moisture in the system Table 1 Accessory Usage Accessory REQUIRED FOR LOW AMBI ENT APPLICATIONS B...

Page 6: ...ilure to follow this caution may result in equipment damage or improper operation Service valves must be wrapped in a heat sinking material such as a wet cloth while brazing CAUTION UNIT DAMAGE HAZARD...

Page 7: ...tdoor unit has not shifted during shipment Ensure tubes are not rubbing against each other or any sheet metal Pay close attention to feeder tubes making sure wire ties on feeder tubes are secure and t...

Page 8: ...contact with tubing sheet metal etc STEP 9 Compressor Crankcase Heater When equipped with a crankcase heater furnish power to heater a minimum of 24 hr before starting unit To furnish power to heater...

Page 9: ...properly start up system 1 After system is evacuated fully open liquid and vapor service valves 2 Unit is shipped with valve stem s closed and caps installed Replace stem caps after system is opened...

Page 10: ...vice port 3 Measure liquid line temperature by attaching an accurate thermistor type or electronic thermometer to liquid line near outdoor coil 4 Refer to unit rating plate for required subcooling tem...

Page 11: ...ing Operation This product utilizes either a standard indoor thermostat or Infinity communication User Interface With a call for cooling the outdoor fan reversing valve and compressor are energized Wh...

Page 12: ...ater than or equal to 100 deg F S Fifteen second delay at termination of defrost before the auxiliary heat W2 is de energized S Twenty second delay at termination of defrost before the outdoor fan is...

Page 13: ...ches on the unit control board or in the Infinity control if used The Infinity Control selection overrides the control board dip switch settings Auto defrost is available with Infinity communicating c...

Page 14: ...he 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 li...

Page 15: ...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 therma...

Page 16: ...ir flow Control Fault 45 Outdoor unit control board has failed Control board needs to be replaced Brown Out 24 v 46 The control voltage is less than 15 5v for at least 4 seconds Com pressor and fan op...

Page 17: ...89 84 342 100 95 90 85 349 102 97 92 87 356 103 98 93 88 363 105 100 95 90 370 106 101 96 91 377 107 102 97 92 384 109 104 99 94 391 110 105 100 95 Liquid Pressure at Service Valve Required Subcooling...

Page 18: ...with 550 psig low side retard S Use hoses with 700 psig service pressure rating S Leak detectors should be designed to detect HFC refrigerant S Puron refrigerant as with other HFCs is only compatible...

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