Bard I36H1D, I42H1D, I30H1, I60H1D, I48H1D Sequence of Operation, Pressure Service Ports, Sound

SEQUENCE OF OPERATION

COOLING PART LOAD – Circuit R-Y1 makes at thermostat pulling in compressor contactor, starting the compressor and outdoor motor. The G (indoor motor) circuit is automatically completed on any call for cooling operation or can be energized by manual fan switch on subbase for constant air circulation.

COOLING FULL LOAD – Circuit R-Y1 & Y2 makes at the thermostat energizing the 2nd stage solenoid in the compressor. The default position of the compressor staging solenoid is non-energized. The compressor will run at low capacity until this solenoid is energized.

HEATING STAGE 1 – A 24V solenoid coil on reversing valve controls heating cycle operation. Two thermostat options, one allowing “Auto” changeover from cycle to cycle and the other constantly energizing solenoid coil during heating season and thus eliminating pressure equalization noise except during defrost, are to be used. On “Auto” option a circuit is completed from R-B and R-Y1 on each heating “on” cycle, energizing reversing valve solenoid and pulling in compressor contactor starting compressor and outdoor motor. R-G also make starting indoor blower motor. Heat pump heating cycle now in operation. The second option has no “Auto” changeover position, but instead energizes the reversing valve solenoid constantly whenever the system switch on subbase is placed in “Heat” position, the “B” terminal being constantly energized from R. A thermostat demand for Stage 1 heat completes R-Y1 circuit, pulling in compressor contactor starting compressor and outdoor motor. R-G also make starting indoor blower motor.

HEATING STAGE 2 – Circuit R-Y1 & Y2 makes at the thermostat energizing the 2nd stage solenoid in the compressor.

PRESSURE SERVICE PORTS

High and low pressure service ports are installed on all units so that the system operating pressures can be observed. Pressure tables can be found later in the manual covering all models. It is imperative to match the correct pressure table to the unit by model number. Upper and lower service doors must be attached to obtain proper reading.

LOWERING OUTDOOR FAN SPEED for

SOUND

Supplied in the Literature Assembly is a Fan Control Resistor Assembly that can be installed to lower the fan speed for reduced sound performance. This Resistor Assembly is to be installed in series with the Outdoor Fan Control Thermistor to change the temperature curve that the fan logic control sees.

It is anticipated that you will see a 2-3% drop in system capacity and efficiency when this resistor is installed.

To install the Resistor Assembly:

1.Locate Fan Control Resistor Assembly in Literature Packet hanging on right inside door of unit.

2.Throw main power disconnect to the “OFF” position to eliminate risk of injury or death due to electrical shock.

3.Remove four (4) screws that retain the control panel cover to the unit.

4.Locate Fan Logic Control Board.

5.Locate one of the red leads of the Fan Control Thermistor where it attaches to the Fan Logic Control and remove it.

6.Install resistor in-line with the thermistor lead removed in Step #5, and then connect back onto the Fan Logic Control Board.

Manual	2100-549G
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