York YPAL 050 User Manual

JOHNSON CONTROLS

FORM 100.50-NOM6 (1207)

 
The Unit Controller will self confi gure when it identifi es 
a space sensor has been installed. Once it identifi es that 
a space sensor is connected, if the input is then removed 
the control will generate a Space Temperature Sensor 
Alarm (19). When this occurs the unit will continue to 
operate and will use the return air temperature input 
in place of the space sensor. If the “SPACE SENSOR 
FAULT OVERRIDE ENABLE” is turned on, the Alarm 
is removed and the unit will continue to use the return 
air temperature input until the space sensor input is 
within range and “SPACE SENSOR FAULT OVERRIDE 
ENABLE” has been turned off. 
 
“SPACE SENSOR FAULT OVERRIDE ENABLE” 
is enabled using parameter 8 under the PROGRAM 
key of the Simplicity Elite control board or under the 
SYSTEMS OPTIONS tab of the Simplicity software 
package. 

When the unit is confi gured as a Constant Volume unit 
with space sensor the Simplicity Control will use the 
same logic for controlling compressors, economizer, 
and heating that it would use with a space sensor but 
uses the return air temperature input instead of the 
space sensor.

When unit is confi gured for VAV with space sensor, 
the Simplicity Elite control will use the return air 
temperature in place of the space sensor to reset between 
the “VAV COOLING SUPPLY AIR TEMP UPPER 
SETPOINT” and the “VAV COOLING SUPPLY AIR 
TEMP LOWER SETPOINT” based on the return air 
temperature in relation to the “VAV SUPPLY AIR TEMP 
RESET SETPOINT”.

This feature can be used on a VAV unit to send a 
hardwired 0 to 10 volts signal to the unit to vary the 
supply air temperature set point between the “VAV 
COOLING SUPPLY AIR TEMP LOWER SETPOINT” 
and  “VAV COOLING SUPPLY AIR TEMP UPPER 
SETPOINT”.  This feature will only work on a VAV 
unit with space sensor control.

The following parameter must be enabled in order to 
use to feature:

“REMOTE CONTROL INPUT ENABLE FOR THIRD 
PARTY BAS” must be enabled using Parameter 22 under 
the PROGRAM key of the Simplicity Elite control board 
or under the SYSTEMS OPTIONS tab of the Simplicity 
PC software package.

The Simplicity Elite control will vary the active cooling 
set point per the following:

•

  Reset voltage less than 1.5 volts DC – No com-

pressor operation.

•

  Reset voltage 1.5 to 2.0 volts DC - “VAV 

•

  Reset voltage 10.0 volts DC - “VAV COOLING 

•

  Reset voltage between 2.0 and 10.0 volts DC 

– linearly between the “VAV COOLING SUP-
PLY AIR TEMP LOWER SETPOINT” and 
“VAV COOLING SUPPLY AIR TEMP UPPER 
SETPOINT”.

•

  The hard wired input is connected to the Sim-

plicity Elite control board at the “REM+” and 
“REM-“ terminals of the P19 connector.

The feature can be used to temporally reduce the 
electrical consumption of the unit by reducing the 
number of compressor that are turned on.  This feature is 
only available as a communicated input to the Simplicity 
Elite control.  The BACnet name is SET_REDLINE and 
the BACnet instance number is BV12.  For Modbus use 
address (HEX) 41L, address (DEC) 65L Bit 0.

If three or more compressors are energized when the 
Simplicity Elite control receives this command the 
Simplicity Control will turn off compressor number 
3 and 4 if energized even if the minimum run time 
requirement has not been met.