Contents
Introduction .................................................................................................................................................................. 1
Wiring inputs and outputs ........................................................................................................................................... 4
Communications wiring .............................................................................................................................................. 6
Protocol overview .................................................................................................................................................. 6
BACnet MS/TP ...................................................................................................................................................... 7
Modbus ................................................................................................................................................................... 9
Troubleshooting Modbus .................................................................................................................... 11
Johnson N2 ......................................................................................................................................................... 12
Troubleshooting N2 ............................................................................................................................. 13
LonWorks ............................................................................................................................................................ 14
Troubleshooting LonWorks ................................................................................................................. 16
Start-up ....................................................................................................................................................................... 17
Sequence of Operation ............................................................................................................................................. 18
Occupancy ........................................................................................................................................................... 18
Supply fan ........................................................................................................................................................... 19
Cooling ................................................................................................................................................................. 19
Economizer ......................................................................................................................................................... 20
Power Exhaust .................................................................................................................................................... 21
Pre-Occupancy Purge ........................................................................................................................................ 21
Unoccupied Free Cooling .................................................................................................................................. 21
Optimal Start ...................................................................................................................................................... 22
Enthalpy control ................................................................................................................................................. 23
Indoor Air CO2 .................................................................................................................................................... 23
Heating ................................................................................................................................................................ 24
Heat Pump operation ........................................................................................................................................ 24
Dehumidification ............................................................................................................................................... 25
Demand Limiting ............................................................................................................................................... 25
Door switch ......................................................................................................................................................... 25
Remote Occupancy ........................................................................................................................................... 26
Fire Shutdown .................................................................................................................................................... 26
Compressor Safety ............................................................................................................................................ 26
Fan Status ........................................................................................................................................................... 26
Filter status ......................................................................................................................................................... 27
Alarms ................................................................................................................................................................. 27
Linkage ................................................................................................................................................................ 29
Air source mode determination....................................................................................................................... 31
Troubleshooting ......................................................................................................................................................... 32
LED's .................................................................................................................................................................... 32
Compliance ................................................................................................................................................................ 34
FCC Compliance ................................................................................................................................................. 34
CE Compliance ................................................................................................................................................... 34
BACnet Compliance........................................................................................................................................... 34