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Table 1 – RTU--OPEN Inputs and Outputs
POINT NAME
BACnet OBJECT
NAME
TYPE OF I/O
CONNECTION PIN
NUMBER(S)
DEDICATED INPUTS
Space Temp / Zone Temp
zone_temp
AI (10K Thermistor)
J20---1, 2
Supply Air Temperature
sa_temp
AI (10K Thermistor)
J2---1, 2
Outdoor Air Temperature
oa_temp
AI (10K Thermistor)
J2---3, 4
Space Temperature Offset Pot
stpt_adj_offset
AI (100K Potentiometer)
J20---3
Safety Chain Feedback
safety_status
DI (24 VAC)
J1---9
Compressor Safety Status
comp_status
DI (24 VAC)
J1---2
Fire Shutdown Status
firedown_status
DI (24 VAC)
J1---10
Enthalpy Status
enthalpy_status
DI (24 VAC)
J2---6
Humidistat Input Status
humstat_status
DI (24 VAC)
J5---7
CONFIGURABLE INPUTS
Indoor Air CO2
iaq
AI (4---20 ma)
J4---2 or J4---5
Outdoor Air CO2
oaq
AI (4---20 ma)
Space Relative Humidity
space_rh
AI (4---20 ma)
Supply Fan Status*
sfan_status
DI (24 VAC)
J5---1 or J5---3 or
J5 5 or J5---7
Filter Status*
filter_status
DI (24 VAC)
Door Contact Input*
door_contact_status
DI (24 VAC)
Occupancy Contact*
occ_contact_status
DI (24 VAC)
OUTPUTS
Economizer Output
econ_output
AO (4---20ma)
J2---5
Supply Fan Relay State
sfan
DO Relay (24VAC , 1A)
J1---4
Compressor 1 Relay State
comp_1
DO Relay (24VAC , 1A)
J1---8
Compressor 2 Relay State
comp_2
DO Relay (24VAC , 1A)
J1---7
Heat Stage 1 Relay State
heat_1
DO Relay (24VAC , 1A)
J1---6
Heat Stage 2 Relay State
heat_2
DO Relay (24VAC , 1A)
J1---5
Power Exhaust Relay State
pexh
DO Relay (24VAC , 1A)
J11---3
Dehumidification Relay State
dehum
DO Relay (24VAC, 1A)
J11---7, 8
* These inputs (if installed) take the place of the default input on the specific channel
Parallel pins J5---1 = J2---6, J5---3 = J1---10, J5---5 = J1---2 are used for filed installation.
Refer to the input configuration and accessory sections for more detail.
Sensors and Accessories
The RTU-OPEN controller is configurable with the
following field-supplied sensors:
NOTE
: Supply air temperature sensor (33ZCSENSAT) is
factory-installed.
S
Space temperature sensor (SPS, SPPL, SPP, SPPF,
33ZCT55SPT, 33ZCT56SPT, or 33ZCT59SPT
S
Indoor air quality sensor (33ZCSENCO2,
33ZCT55CO2, 33ZCT56CO2) required for demand
control ventilation.
S
Outdoor air quality sensor (33ZCTSENCO2)
S
CO
2
aspirator box (C33ZCCASPCO2) required for CO
2
return duct/outside air applications
S
Outdoor air enthalpy switch (33CSENTHSW)
S
Return air enthalpy sensor (33CSENTSEN) required for
differential enthalpy control
S
Space relative humidity sensor (33ZCSENSRH-01)
S
Duct relative humidity (33ZCSENDRH-01)
S
Humidistat (--HL--38MG-029)
S
Smoke Detectors (CRSMKSEN002A00,
CRSMKKIT002A00)
S
Fan and/or Filter Status (CRSTATUS001A00,
CRSTATUS005A00)
User Interfaces
S
BACview 6 Handheld (BV6H)
S
Virtual BACview (USB-L or USB-TKIT required)
S
Field Assistant (USB-TKIT required)
Install Analog Sensors
Supply Air Sensor (SAT)
The factory supplies the discharge (supply) air sensor with
the unit and is pre--wired. On 04-16 size units, the SAT is
secured to the unit’s supply duct opening. This sensor
must be relocated into the supply duct during unit
installation. On 17-30 size units, the SAT is mounted
through the side of the heat chamber below the fan deck,
and does NOT require relocation.
Outdoor Air Sensor (OAT)
The OAT is supplied with the economizer option or
accessory. It is wired through the 12-pin plug (PL6) in the
return air section of the unit and is mounted on the
economizer assembly.
Space Temperature Sensor (SPT)
There are 2 types of SPT sensors available from Carrier,
resistive input non-communicating (T55, T56, and T59)
and Rnet communicating (SPS, SPPL, SPP, and SPPF)
sensors. Each type has a variety of options consisting of:
timed override button, set point adjustment, a LCD
screen, and communication tie in. Space temperature can
be also be written to from a building network or zoning
system. However, it is still recommended that return air
duct sensor be installed to allow stand-alone operation for
back-up. Refer to the configuration section for details on
controller configurations associated with space sensors.