Sequence Of Operation; Constant Volume Economizer Set Point; Variable Air Volume Economizer Set Point - York ECO2 YPAL 050 Installation & Operation Manual

Sequence of Operation

"OUTSIDE AIR HUMIDITY SENSOR INSTALLED"
- must be disabled using Parameter 36 under the
PROGRAM key on the Simplicity Control board or
under the EQUIPMENT INSTALLATION tab in the
Simplicity PC software package.
"RETURN AIR HUMIDITY SENSOR INSTALLED"
- must be disabled using Parameter 38 under the
PROGRAM key on the Simplicity Control board or
under the EQUIPMENT INSTALLATION tab in the
Simplicity PC software package.
"THIRD PARTY BAS ECONOMIZER INSTALLED"
must be enabled using Parameter 58 under the
PROGRAM key on the Simplicity Control board or
under the EQUIPMENT INSTALLATION tab in the
Simplicity PC software package.
In order to use this feature a 2 to 10 VDC external signal
must be sent to the unit through the "BAS ECON +"
and "BAS ECON -" connections on the Unit Control
board.
Sequence of Operation
The Unit Controller sends the 2 to 10 VDC input signal
directly to the analog output terminals "ECO +" and
"ECO -" to the damper actuator. A 2 VDC input from
the external source will result in a 2 VDC signal to the
damper actuator.
If voltage is applied to the "BAS ECON
+" and "BAS ECON -" terminals be-
fore "THIRD PARTY BAS ECONO-
MIZER INSTALLED" is enabled the
Unit Controller can be damaged.

Constant Volume Economizer Set Point

The following parameter must be programmed to allow
economizer operation:
"ECONOMIZER FIRST STAGE SETPOINT" – must be
programmed using Parameter 33 under the PROGRAM
key on the Simplicity control board or under the
ECONOMIZER/EXHAUST tab in the Simplicity PC
software package.
78
"ECONOMIZER SECOND STAGE SETPOINT"
– must be programmed using Parameter 34 under
the PROGRAM key on the Simplicity control board
or under the ECONOMIZER/EXHAUST tab in the
Simplicity PC software package.
The Simplicity Control will try to modulate the outdoor
air damper and the compressors to maintain the supply
air temperature to +/- 1.0° F of the following set points
based on the method of control:
•
With a Y1 input from a thermostat the Simplic-
ity Control will use the "ECONOMIZER FIRST
STAGE SETPOINT".
•
With a Y2, Y3, or Y4 input from a thermostat the
Simplicity Control will use the "ECONOMIZER
SECOND STAGE SETPOINT".
•
When the space temperature is 1.5° F to 1.9°
F above the "CV OCCUPIED COOLING
SETPOINT" or "CV UNOCCUPIED COOLING
SETPOINT" the Simplicity Control will use the
"ECONOMIZER FIRST STAGE SETPOINT".
•
When the space temperature is 2.0° F above the
"CV OCCUPIED COOLING SETPOINT" or
"CV UNOCCUPIED COOLING SETPOINT"
the Simplicity Control will use the "ECONO-
MIZER SECOND STAGE SETPOINT".

Variable Air Volume Economizer Set Point

The Simplicity Control will try to modulate the outdoor
air damper and the compressors to maintain the supply
air temperature to +/- 1.0° F of the following set points
based on the method of control:
•
With a Y1 input from a thermostat the Simplicity
Control will use the "VAV COOLING SUPPLY
AIR TEMP UPPER SETPOINT".
•
With a Y2, Y3, or Y4 input from a thermostat the
Simplicity Control will use the "VAV COOLING
SUPPLY AIR TEMP LOWER SETPOINT".
•
When the space temperature is less then 2.0°
F above the "VAV SUPPLY AIR TEMP RESET
SETPOINT" the Simplicity Control will use the
"VAV COOLING SUPPLY AIR TEMP UPPER
SETPOINT".
FORM 100.50-NOM6 (1207)
JOHNSON CONTROLS