York YACT038-072 Installation Manual page 22

AFFINITY COMBINATION INSTALLATION MANUAL
Microprocessor Control cont.
Heating Operation
Heat, 1st Stage (Y1)
The blower motor is started on low speed immediately, the
loop pump is energized 5 seconds after the "Y1" input is
received, and the compressor is energized on low capacity
10 seconds after the "Y1" input. The ECM blower is switched
to medium speed 15 seconds after "Y1" input.
Heat, 2nd Stage (Y1,Y2) Dual Capacity Units
The second stage compressor will be activated 5 seconds
after receiving a "Y2" input as long as the minimum first
stage compressor run time of 1 minute has expired. The
ECM blower changes from medium to high speed 15
seconds after the "Y2" input.
Heat, 3rd Stage (Y1,Y2,W) Dual Capacity Units
The 1st stage of resistance heat is energized 10 seconds
after "W" input, and with continuous 3rd stage demand, the
second stage of resistance heat will engage after 5 minutes.
Emergency Heat (W Only)
Low speed blower and damper output CR3 will be
energized immediately after receiving (W only). The first
stage auxiliary heater will be energized 10 seconds upon
receiving a (W only) and the blower will shift to high speed
15 seconds after receiving a "W" only input. If the "W" input
is not removed, the second, auxiliary heat output will stage
on, after two minutes.
Cooling Operation
Cool, 1st Stage (Y1,O)
The blower is started immediately, and the loop pump(s)
is energized 5 seconds after the "Y1" input is received. The
compressor will be energized on low capacity 10 seconds
after the "Y1" input. The ECM blower will shift from low to
medium speed 15 seconds after the "Y1" input.
Cool, 2nd Stage (Y1, Y2, O) Dual Capacity Units
The second stage compressor will be activated 5 seconds
after receiving a "Y2" input as long as the minimum first stage
compressor run time of 1 minute has expired. The ECM blower
changes to high speed 15 seconds after the "Y2" input.
Hydronic Cooling Slave Signal (24 vac input on
P6-pin 15 violet wire)
The control board must be operating in cooling mode (Y1
and O inputs) or the cooling slave signal is ignored. When
"Y1", and "O" inputs have been received and a cooling
slave input from heating/cooling thermostat located in a
hydronic heated/force air cooled zone are received the
control will activate CR3 relay to open damper(s) which
will allow for cooling to occur in zone. When cooling slave
input (24VAC) signal is removed the control will turn off the
CR3 relay output, if spring damper operation is selected,
or activate, the CR4 output if POPC damper operation is
selected. This will close field installed damper(s) located in
ductwork. NOTE: The control will not operate in forced air
cooling and hydronic water heating modes simultaneously.
Hot Water Operation
After a hot water input is received, the diverting valve, loop
pump and load water pump are turned on. Five seconds
after hot water input is received the compressor is activated
in second stage. Hydronic Mode Operation with Hydronic
Priority Setting: If the control receives a demand to heat the
space (Y1) from the thermostat during water heating mode
operation, the control will engage medium ECM fan speed
and the first stage auxiliary heat output. The second stage
will be energized at five (5) minutes, following the first
stage. The installer should set medium ECM fan speed for no
less than the minimum required cfm for the installed electric
heat package (see Auxiliary Heat Ratings table).
Blower (G Only)
The blower starts on low speed. Regardless of blower input
(G) from thermostat, the blower will remain on low speed
for 30 seconds at the end of each heating, cooling or
emergency heat cycle.
Lockout Conditions
During lockout mode the appropriate unit and thermostat
lockout LEDs will illuminate. The compressor, loop pump,
load water pump and accessory outputs are de-energized.
Unless the lockout is caused by an ECM low RPM fault,
the blower will continue to run on low speed, and if the
thermostat calls for heating 3rd stage, emergency heat
operation will occur.
Lockout modes can be reset at the thermostat after a five-
second waiting period, which restores normal operation
but keeps the unit lockout LED illuminated. Interruption
of power to the unit will reset a lockout without a waiting
period and clear all lockout LEDs.
High Pressure
This lockout mode occurs when the normally closed safety
switch is opened momentarily. >600 PSI
Low Pressure
This lockout mode occurs when the normally closed switch
is opened for 30 continuous seconds. <40 PSI
Freeze Detection Limit (Water Flow)
This lockout mode occurs when the low source water
thermistor temperature is at or below the selected point
(well 30°F or loop 15°F) for 30 continuous seconds.
ECM Blower RPM
The control board monitors blower RPM to sense if the
blower is not operating. This lockout mode occurs if the
blower RPM falls below the low RPM limit (100 RPM) for 30
continuous seconds.SW3-3 should be set to OFF (No RPM
sensing) on this product.
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