Carrier Understand the Key Features of 48HC Heating Systems
Page 39

Table 9 – RTU Open Controller Inputs and Outputs

 

 

POINT NAME

BACnet OBJECT

 

TYPE OF I/O

CONNECTION PIN

 

 

NAME

 

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)

 

Outdoor Air CO2

oaq

 

AI (4--- 20 ma)

J4--- 2 or J4--- 5

Space Relative Humidity

space_rh

 

AI (4--- 20 ma)

 

Supply Fan Status*

sfan_status

 

DI (24 VAC)

 

Filter Status*

filter_status

 

DI (24 VAC)

J5--- 1 or J5--- 3 or

Door Contact Input*

door_contact_status

 

DI (24 VAC)

J5 5 or J5--- 7

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

LEGEND

 

 

 

 

 

AI

---

Analog Input

 

 

 

 

AO

---

Analog Output

 

 

 

 

DI

---

Discrete Input

 

 

 

 

DO

---

Discrete Output

 

 

 

 

*These inputs (if installed) take the place of the default input on the specific channel according to schematic. Parallel pins J5---1 = J2---6, J5---3 = J1---10, J5---5 = J1---2 are used for field---installation.

48HC

The RTU Open controller requires the use of a Carrier space sensor. A standard thermostat cannot be used with the RTU Open system.

Supply Air Temperature (SAT) Sensor —

On FIOP-equipped 48HC unit, the unit is supplied with a supply-air temperature (SAT) sensor (33ZCSENSAT). This sensor is a tubular probe type, approx 6-inches (12.7 mm) in length. It is a nominal 10-k ohm thermistor.

The SAT is factory-wired. The SAT probe is wire-tied to the supply-air opening (on the horizontal opening end) in its shipping position. Remove the sensor for installation. Re-position the sensor in the flange of the supply-air opening or in the supply air duct (as required by local codes). Drill or punch a 1/2-in. hole in the flange or duct. Use two field-supplied, self-drilling screws to secure the sensor probe in a horizontal orientation. See Fig. 40.

Outdoor Air Temperature (OAT) Sensor —

The OAT is factory-mounted in the EconoMi$er2 (FIOP or accessory). It is a nominal 10k ohm thermistor attached to an eyelet mounting ring.

EconoMi$er2 —

The RTU Open control is used with EconoMi$er2 (option or accessory) for outdoor air management. The damper position is controlled directly by the RTU Open control; EconoMi$er2 has no internal logic device.

Outdoor air management functions can be enhanced with field-installation of these accessory control devices:

Enthalpy control (outdoor air or differential sensors) Space CO2 sensor

Outdoor air CO2 sensor

Field Connections

Field connections for accessory sensors and input devices are made the RTU Open, at plugs J1, J2, J4, J5, J11 and J20. All field control wiring that connects to the RTU Open must be routed through the raceway built into the corner post as shown in Fig. 31. The raceway provides the UL required clearance between high- and low-voltage wiring. Pass the control wires through the hole provided in the corner post, then feed the wires thorough the raceway

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Contents Installation Instructions Safety Considerations Unit Dimensional Drawing 17 Size Unit C10897 Unit Dimensional Drawing 20 and 24 Size Units C10893 Unit Dimensional Drawing 28 Size Unit C10901 Operating Weights Plan for Unit LocationRoof Mount Plan for Sequence of Unit Installation Inspect unitProvide Unit Support Roof Curb Details 17 Size Unit Roof Curb Details 20 and 24 Size Units Roof Curb Details 28 Size Unit Rig and Place Unit Field Fabricate DuctworkInstall Outside Air Hood Factory Option Horizontal Duct ConnectionPositioning on Curb Gas Supply Line Install Flue Hood and Combustion Air HoodInstall Gas Piping To assemble the outside air hoodNatural Gas Supply Line Pressure Ranges Typical 3/4-in NPT Field Supplied Piping PartsOrifice Hole Factory-Option Thru-Base ConnectionsInstall External Condensate Trap and Line Field Power SupplyMake Electrical Connections All Units Units with Factory-Installed DisconnectPowered Convenience Outlet Wiring Unit without Thru-Base Connection Kit Field Control WiringUnits without Thru-Base Connections ThermostatTypical Low-Voltage Control Connections Transformer Connection for 208-v Power SupplyTo connect the Thermidistat device 33CS2PPRH-01 Humidi-MiZerRControl ConnectionsHumidi-MiZer Space RH Controller To connect the Carrier humidistat HL38MG029OAT RRS Srtn PremierLink Controller PremierLinkt Factory-OptionPremierLink Wiring Schematic PremierLink Wiring Schematic with Humidi-MiZerR PremierLink Sensor Usage Supply Air Temperature SAT SensorField Connections EconoMi$er2Thermostat Mode Space Sensor ModeSpace Sensors Configure the Unit for Thermostat ModeIndoor Air Quality CO2 Sensor Economizer ControlsTo wire the sensor Space Relative Humidity Sensor InstallationSmoke Detector/Fire Shutdown FSD Filter Status SwitchSupply Fan Status Switch Power Exhaust outputConnecting CCN Bus Color Code Recommendations CCN Communication BusRecommended Cables RTU Open Multi-Protocol Control Board RTU Open Control SystemRTU Open System Control Wiring Diagram RTU Open System Control Wiring Diagram with Humidi-MiZerR Type of I/O Connection PIN Name Numbers Dedicated Inputs RTU Open Controller Inputs and OutputsRTU Open T-55 Sensor Connections Space Temperature SPT SensorsRelative Humidity Sensors Space or Duct Mounted Space Relative Humidity Sensor Typical WiringConnecting Discrete Inputs Duct Relative Humidity Sensor Typical WiringGeneral Communication Wiring ProtocolsRTU Open Troubleshooting Local AccessOutdoor Air Enthalpy Control LEDsDifferential Enthalpy Control Wiring Return Air Sensor Tube InstallationSmoke Detectors Additional Application Data To install the return air sensor sampling tubeUnit Wire/Fuse or Hacr Breaker Sizing Data Smoke Detector Test MagnetUnit NOM IFM FAN Motor Exhaust Unbalanced 3-Phase Supply Voltage Pre-Start and Start-Up Adjust Factory-Installed OptionsInstall Accessories EconoMi$er IV Occupancy Switch48HC Catalog No 48HC---11SI

48HC specifications

The Carrier 48HC is a highly efficient rooftop HVAC unit designed for commercial applications that prioritize both performance and energy savings. This unit embodies Carrier's commitment to innovation by integrating advanced technologies and features that address the modern demands of building climate control.

One of the standout features of the Carrier 48HC is its exceptional energy efficiency. Employing the latest in variable-speed compressor technology, the unit adjusts its output based on the specific cooling needs of the space, which not only enhances comfort levels but also significantly reduces energy consumption. This feature is crucial for businesses looking to lower their operational costs while minimizing their environmental impact.

The Carrier 48HC is also equipped with a comprehensive range of control options. Through its intelligent control systems, users can utilize features such as demand ventilation, which optimizes indoor air quality while maintaining energy efficiency. The integration with building management systems (BMS) further enhances operational effectiveness, allowing real-time monitoring and adjustments from a centralized point.

Additionally, the 48HC is designed with durability in mind. Its robust construction resists harsh weather conditions and ensures long-lasting performance. The unit features advanced corrosion-resistant materials and coatings, which prolong its lifespan and reduce maintenance needs. This durability makes the 48HC a reliable choice for varying environments, whether it’s an industrial setting or a more delicate commercial space.

The unit’s compact design also deserves mention, as it facilitates easier installation on rooftops without taking up excessive space. The modular design allows for customization, enabling businesses to tailor their systems to fit specific heating and cooling requirements.

In terms of comfort, the Carrier 48HC employs efficient air distribution technology that ensures even airflow throughout the space. This greatly enhances occupant comfort by eliminating hot or cold spots, promoting a consistent indoor climate.

Finally, the 48HC complies with stringent environmental regulations and standards. With options for environmentally-friendly refrigerants, it supports businesses in their sustainability efforts while operating effectively under current regulations.

In summary, the Carrier 48HC stands out in the crowded HVAC market due to its advanced technology, energy efficiency, durability, and adaptability for commercial applications, making it a top choice for those looking to invest in a reliable and effective climate control solution.
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