York AFFINITY OptiHeat YAW040 Installation Manual page 29

The Aurora 'Base' Control System cont.
Fault Retry – in the fault condition, the control will stage off
the outputs and then "try again" to satisfy the thermostat
Y input call. Once the thermostat input calls are satisfied,
the control will continue on as if no fault occurred. If 3
consecutive faults occur without satisfying the thermostat
Y input call, then the control will go to Lockout mode.
Lockout – The Alarm output (ALM) and Lockout output (L)
will be turned on. The fault type identification display LED1
(Red) shall flash the fault code. To reset lockout conditions
with SW2-8 On, thermostat inputs "Y1", "Y2", and "W"
must be removed for at least 3 seconds. To reset lockout
conditions with SW2-8 Off, thermostat inputs "Y1", "Y2",
"W", and "DH" must be removed for at least 3 seconds.
Lockout may also be reset by turning power off for at least
30 seconds or by enabling the emergency shutdown input
for at least 3 seconds.
High Pressure – fault is recognized when the Normally
Closed High Pressure Switch, P4-9/10 opens, no matter
how momentarily. The High Pressure Switch is electrically in
series with the Compressor Contactor and serves as a hard-
wired limit switch if an overpressure condition should occur.
Low Pressure - fault is recognized when the Normally
Closed Low Pressure Switch, P4-7/8 is continuously open
for 30 seconds. Closure of the LPS any time during the 30
second recognition time restarts the 30 second continuous
open requirement. A continuously open LPS shall not be
recognized during the 2 minute startup bypass time.
Loss of Charge – fault is recognized when the Normally
Closed Low Pressure Switch, P4-7/8 is open prior to the
compressor starting.
Freeze Detection (Source Coax) - set points shall be
either 30°F or 15°F. When the thermistor temperature
drops below the selected set point, the control shall begin
counting down the 30 seconds delay. If the thermistor
value rises above the selected set point, then the count
should reset. The resistance value must remain below the
selected set point for the entire length of the appropriate
delay to be recognized as a fault. This fault will be ignored
for the initial 2 minutes of the compressor run time.
Freeze Detection (Load Coax) - uses the FP2 input to
protect against ice formation on the coax. The FP2 input
will operate exactly like FP1.
AFFINITY SINGLE STAGE HYDRONIC WITH OPTIHEAT INSTALLATION MANUAL
Over/Under Voltage Shutdown - An over/under voltage
condition exists when the control voltage is outside the
range of 18 VAC to 30 VAC. If the over/under voltage
shutdown lasts for 15 minutes, the lockout and alarm relay
will be energized. Over/under voltage shutdown is self-
resetting in that if the voltage comes back within range
of 18 VAC to 30 VAC for at least 0.5 seconds, then normal
operation is restored.
Operation Description
Power Up - The unit will not operate until all the inputs and
safety controls are checked for normal conditions. The unit
has a 5 to 80 second random start delay at power up. Then
the compressor has a 4 minute anti-short cycle delay after
the random start delay.
Standby In standby mode, Y1, Y2, W, DH, and G are not
active. Input O may be active. The blower and compressor
will be off.
Heating Operation
Heating, 1st Stage (Y1) - The compressor is energized 10
seconds after the Y1 input is received.
Cooling Operation
In all cooling operations, the reversing valve directly tracks
the O input. Thus, anytime the O input is present, the
reversing valve will be energized.
Cooling, 1st Stage (Y1, O) - The compressor is energized 10
seconds after the Y1 input is received.
Emergency Shutdown - Four (4) seconds after a valid ES
input, P2-7 is present, all control outputs will be turned off
and remain off until the emergency shutdown input is no
longer present. The first time that the compressor is started
after the control exits the emergency shutdown mode,
there will be an anti-short cycle delay followed by a random
start delay. Input must be tied to common to activate.
Load Shed - The LS input disables all outputs from the
ABC control board. When the LS input has been cleared,
the anti-short cycle timer and random start timer will be
initiated. Input must be tied to common to activate.
29