Table of Contents
Advertisement
Contents
Introduction .................................................................................................................................................................. 1
What is the RTU Open controller? ...................................................................................................................... 1
Specifications ........................................................................................................................................................ 3
Safety considerations........................................................................................................................................... 4
Installing the RTU Open ............................................................................................................................................... 5
Field-supplied hardware ...................................................................................................................................... 5
To mount the RTU Open ....................................................................................................................................... 6
To wire the controller for power.......................................................................................................................... 7
To use the rooftop equipment control power transformer.................................................................. 8
To use an auxiliary control power transformer .................................................................................... 9
To set the controller's address ......................................................................................................................... 11
To set the controller's communications protocol and baud rate ............................................................... 11
Wiring for communications .............................................................................................................................. 12
Wiring specifications for BACnet MS/TP and ARC156 ...................................................................... 12
To wire the controller to the BACnet network .................................................................................... 12
Wiring inputs and outputs ................................................................................................................................ 13
Input wiring specifications .................................................................................................................. 14
Inputs ................................................................................................................................................... 15
Binary outputs ..................................................................................................................................... 15
Analog outputs .................................................................................................................................... 15
To wire inputs and outputs ................................................................................................................. 16
Wiring sensors and switches to the controller .............................................................................................. 20
Field-supplied sensor hardware ......................................................................................................... 21
Wiring devices to the RTU Open's Rnet port ...................................................................................... 22
Wiring a Supply Air Temperature sensor ............................................................................................ 27
Wiring a duct air temperature sensor ................................................................................................ 28
Wiring an outdoor air temperature sensor ........................................................................................ 29
Wiring a CO2 sensor ............................................................................................................................ 30
Wiring an outdoor air quality sensor .................................................................................................. 32
Wiring a relative humidity sensor ....................................................................................................... 33
Wiring a Humidistat ............................................................................................................................. 34
Wiring an enthalpy switch ................................................................................................................... 35
Wiring a status switch ......................................................................................................................... 37
Wiring a compressor safety ................................................................................................................ 38
Wiring an occupancy switch or door contact ..................................................................................... 39
Start-up ....................................................................................................................................................................... 41
Service Test ......................................................................................................................................................... 41
Configuring the RTU Open's properties .......................................................................................................... 43
Sequence of Operation ............................................................................................................................................. 44
Occupancy ........................................................................................................................................................... 44
Supply fan ........................................................................................................................................................... 45
Cooling ................................................................................................................................................................. 45
Economizer ......................................................................................................................................................... 46
Power Exhaust .................................................................................................................................................... 47
Pre-Occupancy Purge ........................................................................................................................................ 48
Unoccupied Free Cooling .................................................................................................................................. 48
Optimal Start ...................................................................................................................................................... 48
Enthalpy control ................................................................................................................................................. 50
Indoor Air CO2 .................................................................................................................................................... 50
Heating ................................................................................................................................................................ 51
Heat Pump operation ........................................................................................................................................ 51
Dehumidification ............................................................................................................................................... 52
Advertisement
Table of Contents
