Sequence Of Operation; Pressure Service Ports - Bard I-TEC Series Installation Instructions Manual

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.
This unit employs high-flow Coremax valves instead of
the typical Shrader type valves.
WARNING! Do NOT use a Schrader valve core removal
tool with these valves. Use of such a tool could result
in eye injuries or refrigerant burns!
To change a Coremax valve without first removing the
refrigerant, a special tool is required which can be
obtained at www.fastestinc.com/en/SCCA07H. See the
replacement parts manual for replacement core part
numbers.
Manual 2100-578L
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