York ECO2 YPAL 050 - Manual (Page 77)

77 JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
5
Single Enthalpy
The following parameters must be programmed to allow
economizer operation:
“ E C O N O M I Z E R O U T S I D E A I R E N T H A L P Y
SETPOINT” – must be programmed using Parameter
37 under the PROGRAM key on the Simplicity control
board or under the ECONOMIZER/EXHAUST tab in
the Simplicity PC software package.
“OUTSIDE AIR HUMIDITY SENSOR INSTALLED”
– must be enabled using Parameter 36 under the
PROGRAM key on the Simplicity control board or
under the EQUIPMENT INSTALLATION tab in the
Simplicity PC software package.
The economizer will become active and use outdoor air
for cooling when:
•
The outside air enthalpy is less then or equal to
the “ECONOMIZER OUTSIDE AIR ENTHALPY
SETPOINT”.
•
The Simplicity Control has a demand for cooling
operation.
•
If the outdoor air enthalpy was above the
“ECONOMIZER OUTSIDE AIR ENTHALPY
SETPOINT” when the cooling cycle was initiated
the Simplicity Control will activate economizer
operation when the outdoor air enthalpy is 1.0
BTU/LB below the “ECONOMIZER OUTSIDE
AIR ENTHALPY SETPOINT”.
The economizer will become inactive and eliminate the
use of outdoor air for cooling when:
•
The outside air enthalpy is 1.0 BTU/LB greater
than the “ECONOMIZER OUTSIDE AIR
ENTHALPY SETPOINT”.
•
The Simplicity Control does not have an Occu-
pied or Unoccupied cooling demand.
Dual Enthalpy
The following parameter must be programmed to allow
economizer operation:
“RETURN AIR HUMIDITY SENSOR INSTALLED”
– must be enabled using Parameter 38 under the
PROGRAM key on the Simplicity control board or
under the EQUIPMENT INSTALLATION tab in the
Simplicity PC software package.
“DIFFERENTIAL ENTHALPY MODE ENABLED” must
be turned ON under the ECONOMIZER/EXHAUST tab
in the Simplicity PC software package.
The economizer will become active and use outdoor air
for cooling when:
•
The outside air enthalpy is 1.0 BTU/LB less then
the return air enthalpy.
•
The Simplicity Control has a demand for cooling
operation.
The economizer will become inactive and eliminate the
use of outdoor air for cooling when:
•
The outside air enthalpy is equal to or greater
than the return air enthalpy.
•
The Simplicity Control does not have an Occu-
pied or Unoccupied cooling demand.
BAS ECONOMIZER OPERATION
This feature allows the outdoor/return air damper to be
controlled by an external 2 to 10 VDC input.
The following parameters must be programmed to allow
BAS ECONOMIZER OPERATION:
“ECONOMIZER INSTALLED” - must be disabled using
Parameter 32 under the PROGRAM key on the Simplicity
Control board or under the ECONOMIZER/EXHAUST
tab in the Simplicity PC software package.