York YLAA0041 - Page 6

JOHNSON CONTROLS
6
FORM 150.72-ICOM6
ISSUE DATE: 08/03/2022
TABLE OF CONTENTS (CONT’D)
SECTION 6 – COMMISSIONING ....................................................................................................................... 111
Preparation – Power Off ............................................................................................................................... 111
Commissioning the Pump VFD .................................................................................................................... 114
Preparation – Power On ............................................................................................................................... 114
Determining Proper Oil Levels ..................................................................................................................... 118
SECTION 7 – UNIT CONTROLS ........................................................................................................................123
Introduction ...................................................................................................................................................123
IPU II and I/O Boards ...................................................................................................................................123
Transformer .................................................................................................................................................124
Display ..........................................................................................................................................................124
Keypad .........................................................................................................................................................124
Unit Switch ...................................................................................................................................................124
Battery Backup .............................................................................................................................................124
Programming the Number of Compressors ..................................................................................................124
Status Key ....................................................................................................................................................125
Display/Print Keys ........................................................................................................................................133
Entry Keys ....................................................................................................................................................141
Setpoints Keys .............................................................................................................................................142
Schedule/Advance Day Key ......................................................................................................................... 143
Program Key ................................................................................................................................................145
Unit Keys .....................................................................................................................................................151
BACnet, Modbus, N2, and Yorktalk 2 Communications ...............................................................................159
SECTION 8 – UNIT OPERATION ......................................................................................................................175
Capacity Control ........................................................................................................................................... 175
Suction Pressure Limit Controls ...................................................................................................................176
Discharge Pressure Limit Controls ............................................................................................................... 176
Leaving Chilled Liquid Control ......................................................................................................................176
Leaving Chilled Liquid Control Override to Reduce Cycling .........................................................................177
Leaving Chilled Liquid System Lead/Lag and Compressor Sequencing ......................................................178
Return Chilled Liquid System Lead/Lag and Compressor Sequencing .......................................................178
Anti-Recycle Timer .......................................................................................................................................178
Anti-Coincidence Timer ................................................................................................................................178
Evaporator Pump Control and YORK Hydro Kit Pump Control .................................................................... 178
Evaporator Heater Control ...........................................................................................................................179
Pumpdown Control ....................................................................................................................................... 179
Standard Condenser Fan Control ................................................................................................................179
VSD Fan ....................................................................................................................................................... 179
Changing the Switch Point of the Thermal Dispersion Flow Switch ............................................................. 179
Load Limiting ................................................................................................................................................183
Compressor Run Status ...............................................................................................................................183
Alarm Status ................................................................................................................................................. 183
Remote BAS/EMS Temperature Reset Using a Voltage or Current Signal .................................................. 184