York YPAL 060, YPAL 061, YPAL 050, YPAL 051 manual Variable Air Volume VAV

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.

FORM 100.50-NOM6 (1207)

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.

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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.

JOHNSON CONTROLS 75