F: Modbus Connections - Greenheck DOAS v8.1 Reference Manual

Alarm Table - Latest Alarm (BACnet IV-5 or Modbus 30202)
171 OA Damper Fault - Econ and shouldn't be
172 OAD Fault - Damper not Modulating
173 OAD Fault - Excess Outdoor Air
174 IG Furnace 1 - Combustion Fan Alarm
175 IG Furnace 2 - Combustion Fan Alarm
176 Supply Fan - VFD Offline
177 Exhaust Fan - VFD Offline
178 Return Fan - VFD Offline
179 Energy Recovery - VFD Offline
180 Embedded EVD Error
181 SF VFD Alarm - Check VFD
+V
Tx- Rx+ GND
GND
TERM
BLACK
RED
PWR GND NETB NETA
PWR NETB NETA
GND
SHIELDED CABLE
DRWG: 3686894-00
50 Microprocessor Controller for DOAS
Appendix E: Points List
Appendix F: Factory ModBus Connections
MODBUS CONNECTIONS
UNIT CONTROLLER
COMPONENTS FIELD MOUNTED AND WIRED IN ROOM/SPACE
SPACE THERMOSTAT 1 SPACE THERMOSTAT 2
(OPTIONAL)
NET
NET
GND
PWR PWR
B A
SHIELDED CABLE
MODBUS CONNECTIONS
UNIT CONTROLLER
SPACE THERMOSTAT 3
(OPTIONAL) (OPTIONAL)
NET NET
NET
GND
PWR
B A B
SHIELDED CABLE
FIELD WIRING
FACTORY WIRING
SPACE THERMOSTAT 4
(OPTIONAL)
NET
NET NET
GND
PWR
A B A
SHIELDED CABLE
FIELD WIRING
GND