AHI Carrier Catalog | Page 745

AIR-COOLED CONDENSING UNITS  38RBS Remote Pro-Dialog+ interface This interface can be installed up to 300 m away. It includes a box that can be mounted inside the building. The power supply is provided via a 220 V/24 V transformer supplied. ■■ Ease-of-use -- Backlit LCD interface (option) includes a manual control potentiometer to ensure legibility under any lighting conditions. -- The information is displayed clearly in English, French, German, Italian and Spanish (for other languages please consult Carrier) -- The Pro-Dialog+ navigation uses intuitive treestructure menus, similar to the Internet navigators. They are user-friendly and permit quick access to the principal operat-ing parameters: number of compressors operating, suction/discharge pressure, compressor operating hours, setpoint, air temperature. Room temperature and supply air temperature sensors for capacity control (option) ■■ T  he room temperature sensor permits temperature adjust-ment using a potentiometer. ■■ The supply air temperature sensor must be installed in the air handling unit air flow to control the minimum supply air temperature (adjustable via the remote Pro-Dialog+ interface. Adustable room temperature sensor (option) Pro-Dialog+ interface Circuit B Total Capacity PRO-DIALOG+ Features and advantages C A R R I E R 2 0 1 6 / 2 0 1 7 Easy and fast installation ■■ Physical features -- Small unit footprint with a low height (1371 mm) for easy installation in any application. -- The unit is enclosed by easily removable panels, covering all components (except air heat exchanger and fans). ■■ Simplified electrical connections -- A single power supply point without neutral -- Main disconnect switch (option 70) with high trip capacity ■■ The control circuit of the 38RBS units is equipped with a standard low-voltage transformer (24 V). This transformer can also supply the other electrical components of the air conditioning system: room thermostat and pumpdown solenoid valves. ■■ Fast commissioning -- Systematic factory operation test before shipment -- Quick-test function for step-by-step verification of the instruments, electrical components and motors. Economical operation ■■ Increased energy efficiency at part load The refrigerant circuit includes several compressors connected in parallel. At part load, around 99% of the operating time, only the compressors that are absolutely necessary operate. At these conditions the compressors operating are more energy efficient, as they use the total condenser and evaporator capacity. ■■ Reduced maintenance costs -- Maintenance-free scroll compressors -- Fast diagnosis of possible incidents and their history via the Pro-Dialog+ control -- R410A refrigerant is easier to use than other refrigerant blends 745 AIR TREATMENT ■■ Compressors -- Low-noise scroll compressors with low vibration level -- The compressor assembly is installed on an independent chassis and supported by anti-vibration moun tings -- Dynamic suction and discharge piping support, minimising vibration transmission (Carrier patent) ■■ Condenser section -- Vertical condenser coils -- Protection grilles on anti-vibration mountings to protect the heat exchanger against possible shocks. -- Low-noise latest-generation Flying Bird IV fans, made of a composite material (Carrier patent) are now even quieter and do not generate intrusive low-frequency noise -- Fan motor controlled by a variable-frequency controller, to allow reduction of the fan speed, if the extra low noise option 15LS is selected. -- Rigid fan installation for reduced start-up noise (Carrier patent) ■■ The refrigerant circuit includes all components for easy connection to a direct-expansion air handling unit: filter drier, moisture sight glass, high and low pressure switch, as well as solenoid valves for pumpdown (to be installed on the evaporator). All pipes and the refrigeration components are welded. From size 38RBS 140 onwards, two independent refrigerant circuits ensure partial cooling capacity in all circumstances, and more flexible operation at part load. ■■ Year-round operation The 38RBS units are designed for year-round operation, and operate without the use of accessories down to -10°C. A control algorithm intelligently manages operation of the fans. Option 28 allows stable unit operation at air tempera-tures below -10°C and down to -20°C. CONTROLS Features