York B1HA018A06 Installation Instruction

Contents

York B1HA018A06 Installation Instruction Manual pdf 15 page image

Anti-short Cycle TimerThis unit has an anti-short cycle timer built in to the defrost con-trol. This timer will not permit the compressor to start within fiveminutes after the completion of the last cycle or power interrup-tion. To bypass the anti-short cycle feature, short the “TEST”pins together for 2 seconds.The following sequences of operation are based on using astandard single-stage heat pump thermostat.Cooling OperationWITH POWER TO UNIT AND THERMOSTAT IN COOLINGMODE.1. If the fan switch on the thermostat is in the “ON” position,the 24 volts at “G” will energize the “K1" relay on the fancontrol board, close the ”K1" relay contacts, and energizethe indoor blower motor. If the fan switch on the thermostatis in the “AUTO” position, the blower will operate only whenthere is a call for cooling by the thermostat.2. On a call for cooling, the thermostat will send 24 volts to “Y”and “O” on the fan control board. After the anti-short cycleperiod is complete,The 24 volt signal will energize contac-tor “M1", and the reversing valve solenoid. Power will besupplied to the compressor and outdoor fan motor, and thereversing valve will switch to the cooling position. If the fanswitch on the thermostat is on the ”AUTO" position, the fancontrol will energize the indoor blower.3. When the demand for cooling has been satisfied, the 24volt “Y” signal is removed and the “M1" contactor will be de-energized. If the fan switch on the thermostat is in the ”ON"position, the indoor blower will continue to run. If the fanswitch is in the “AUTO” position, the “K1" relay will open andde-energize the indoor blower motor after a 60 second de-lay,Heating OperationWITH POWER TO UNIT AND THERMOSTAT IN HEATINGMODE.1. If the fan switch on the thermostat is in the “ON” position,the 24 volts at “G” will energize the “K1" relay on the fancontrol board, close the ”K1" relay contacts, and energizethe indoor blower motor. If the fan switch on the thermostatis in the “AUTO” position, the blower will operate only whenthere is a call for heating by the thermostat.2. On a call for heating, the thermostat will send 24 volts to “Y”on the fan control board. After the anti-short cycle period iscomplete, the 24 volts signal will energize contactor coil“M1" and power will be supplied to the compressor and out-door fan motor. The reversing valve will remain in the heat-ing position. If the fan switch on the thermostat is in the”AUTO" position, the fan control will energize the indoorblower.3. For units equipped with supplementary electric heat, if theheat pump cannot meet the demand, the thermostat “W”will send 24 volts to “W2" on the fan control board. This sig-nal will also be sent through the defrost control terminals”W" and “W1/66" and back to the fan control ”W1". This 24volt signal will energize all stages of electric heat.4. When the heating demand is satisfied, the electric heat willbe de-energized when the 24 volt “W” signal is removed,and the “M1" contactor will be de-energized when the 24volt ”Y" signal is removed. If the fan switch on the thermo-stat is in the “ON” position, the indoor blower will continue torun. If the fan switch is in the “AUTO” position, the “K1" relaywill open and de-energize the indoor blower motor after theappropriate time delay.Please refer to Tables 7 and 8 for more information.Defrost OperationThe minimum time between defrosts can be field selected at30, 60 or 90 minutes. The default time is 90 minutes if thejumper is not installed.Defrost will initiate when the defrost sensor, located on the out-door coil, senses a temperature below 31°F and when the timesince the last defrost is greater than the selected time on thedefrost control. The defrost cycle terminates when either thedefrost sensor reaches 55°F or the unit has been in defrostmode for 10 minutes. If the room thermostat opens during de-frost, the unit will resume operation in defrost when the thermo-stat re-closes.During the defrost mode, the defrost control will provide a 24volt signal from terminal “W1/66" to the fan control terminal”W1". This signal will energize electric heat stage 1, if the unit isso equipped.For trouble shooting purposes, the defrost cycle can be manu-ally initiated by shorting the “TEST” pins together for 5 sec-onds. Defrost will terminate normally during the “TEST” mode.Heat Pump Safety Switch OperationIf the unit is equipped with the field installed upgrade safetypackage, the refrigeration system will be protected againsthigh or low refrigerant pressure and low indoor coil tempera-ture. If any of these three safety switches opens, the unit will beshut off for the 5 minute anti-short cycle time. Once this has ex-pired, a six hour elapsed run timer begins. If a second openingof a safety switch occurs during this six hour period, the com-pressor will be locked out.Resetting the lockout function is accomplished by;1. Removing power from the control's thermostat 1st stage(Y) input for a time not to exceed 5 seconds (ON-OFF-ON).2. Removing power from “R” for more than 2 seconds.3. Shorting the “TEST” pins together for more than 2 seconds.Electric Heat Limit Switch OperationThe limit switch responds to over temperature conditions in theair duct. Opening of the device results in dropping power to therelays. The control logic will also respond by turning off the re-lays. After four limit cycle trips the unit goes into a 1 hour softlockout period. If during this period the control “sees” anotherlimit cycle, the unit will go into a hard lockout condition. Once ina hard lockout state, the fan is locked on and the heaters aredisabled. Only a power cycle will clear the state.During the soft lockout period, the fan responds to thermostatinput but the heaters are enabled. This is to sense a failedheater relay. The limit cycle count is reset at the start of a heatrequest. If the limit remains open for period of 80 seconds ormore, the control is immediately put into a hard lockout condi-tion. Only a power cycle will clear this state.Unitary Products Group 15035-16004-001-A-0202SECURE OWNER'S APPROVAL: When the system is functioning properly, secure the owner's approval. Show himthe location of all disconnect switches and the thermostat. Teach him how to start and stop the unit and how to adjust tem-perature settings within the limitations of the system.SEQUENCE OF OPERATION