York YPAL 060 User Manual

Page of 168
75
JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
5
The Simplicity Control monitors the operation of the 
supply fan by checking the status of a digital input from 
an air proving switch.  After 90 seconds of operation, 
the Simplicity Control looks for a high state (24-volt 
input) from the air proving switch circuit at the “APS” 
connections at the P11 connector on the Simplicity 
control board.  If this input does not go to the high state 
in this time frame the Simplicity Control will set an Air 
Pressure Switch Unit Lockout, Alarm Code 24 and turn 
off all outputs.
The Simplicity Control will retry the fan output every 
30 minutes for three retries. If after three retires it still 
cannot qualify the fan, it will continue the alarm and 
lock out all heating and cooling operation.  If the switch 
closes during one of the restarts, the control will resume 
normal operation and clear the active alarm.
An Air Pressure Switch Unit Lockout will also be 
declared if the input goes low, for 2 seconds, during 
normal supply fan operation.
The Simplicity Control also monitors the supply fan 
operation in the off cycle.  90 seconds after the digital 
output from the Simplicity control supply fan circuit 
goes low (0 volts) the Simplicity Control checks the 
status of the digital input from the air proving switch 
circuit.  If the state of the circuit remains high (24-volts) 
the Simplicity Control will set an Air Pressure Switch 
stuck closed, Alarm Code 25.  As soon as the pressure 
switch opens, the Simplicity Control will resume normal 
operation.
On a call for supply fan operation, the Simplicity 
Control sends a 24 VAC signal from the FAN terminal 
of the P13 connector to the supply fan relay.
Variable Air Volume (VAV)
The supply will be energized when:
  The supply fan has been off for 10 seconds and 
anyone of the following occurs:
–  The unit is in the occupied mode.
–  The unit is in the Unoccupied heating or 
cooling mode and there is a 24 volt input to 
terminal Y1, Y2, Y3, Y4, W1, W2, or W3 of 
the Simplicity control terminal board and the 
“COOL, FAN ON DELAY” or “HEAT, FAN 
ON DELAY”
 have timed out.  The “HEAT, 
FAN ON DELAY”
 timer does not start until 
the control receives a signal that the gas valve 
is energized.
The supply fan will be de-energized when:
  The supply fan has been on for 30 seconds and 
anyone of the following occurs:
–  Any time the unit goes unoccupied and there 
is no call for cooling or heating operation.
–  Any time the 24 volt input to terminal Y1, 
Y2, Y3, Y4, W1, W2, or W3 of the Simplic-
ity control terminal board is removed and the 
“COOL, FAN OFF DELAY” or “HEAT, FAN 
OFF DELAY”
 have timed out.  The “HEAT, 
FAN OFF DELAY”
 timer does not start until 
the control receives a signal that the gas valve 
is de-energized.
The Simplicity Control monitors the operation of the 
supply fan by checking the status of a digital input from 
an air proving switch.  After 90 seconds of operation, 
the Simplicity Control looks for a high state (24-volt 
input) from the air proving switch circuit at the “APS” 
connections at the P11 connector on the Simplicity 
control board.  If this input does not go to the high state 
in this time frame the Simplicity Control will set an Air 
Pressure Switch Unit Lockout, Alarm Code 24 and turn 
off all outputs.  The Simplicity Control also monitors 
the duct static pressure input during this time.  If the 
duct static pressure is above 0.05” WC the control will 
generate a Air Pressure Switch Unit Lockout, Alarm 
Code 24 but continue to operate.
The Simplicity Control will retry the fan output every 
30 minutes for three retries. If after three retires it still 
cannot qualify the fan, it will continue the alarm and 
lock out all heating and cooling operation.  If the switch 
closes during one of the restarts, the control will resume 
normal operation and clear the active alarm.
An Air Pressure Switch Unit Lockout will also be 
declared if the input goes low, for 2 seconds, during 
normal supply fan operation.
The Simplicity Control also monitors the supply fan 
operation in the off cycle.  90 seconds after the digital 
output from the Simplicity Control supply fan circuit 
goes low (0 volts) the Simplicity Control checks the 
status of the digital input from the air proving switch 
circuit.  If the state of the circuit remains high (24-volts) 
the Simplicity Control will set an Air Pressure Switch 
stuck closed, Alarm Code 25.  As soon as the pressure 
switch opens the Simplicity Control will resume normal 
operation.