AHI Carrier Catalog | Page 219

WATER-COOLED/CONDENSERLESS LIQUID CHILLERS 30WG/30WGA 020-090 Pro-Dialog+ is a numerical control that combines intelligence with operating simplicity. Depending on the options used, the unit manages the operation of compressors, evaporaor and condenser water pumps and fans (drycooler). ■■ Optimised energy management -- A patented auto-adaptive algorithm optimises the condensing pressure at part load to reduce compressor load and ensure perfect supply for the evaporator with liquid refrigerant. The algorithm controls the operation of the variable-speed condenser water pump and the fans (drycooler) -- Pro-Dialog+ automatically resets the chilledwater temperature setpoint based on the outside air temperature or the return water temperature. The control can also operate on a second setpoint (example: unoccupied mode). Pro-Dialog+ interface \\MAINMENU\STATUS CAPB_T DEM_LIM SP CTRL_PNT EMSTOP 0 100 4.2 -28.9 dsable % % °C °C Circuit B Total Capacity START/STOP ENTER PRO-DIALOG+ ■■ Ease-of-use -- The Pro-Dialog+ interface includes five keys that permit navigation via intuitive tree-structure menus. Access to the information is very quick. -- This new backlit LCD interface includes control by a contrast potiometer for optimised visibility in all lighting conditions. -- The information is clearly displayed in English, French, German, Italian and Spanish (for other languages please consult Carrier Service). -- The Pro-Dialog+ navigation uses intuitive treestructure menus, similar to the Internet navigators. The menus are user-friendly and permit quick access to the principal operating parameters: number of compressors operating, suction/discharge pressure, compressor operating hours, setpoint, temperatures. ■■ Remote control option Pro-Dialog+ permits control and monitoring of the unit using a wired interface: -- Start/stop -- Operating mode selection: cooling or heating -- Demand limit -- Dual setpoint -- User safety loop. The control remotely reports any problem. COOLING Pro-Dialog+ control The CCN clock board connection offers other control possibilities: Two independent time schedules to control: -- Unit start/stop -- Operation at a second chilled-water setpoint (for example: unoccupied mode) -- Operation of two units in parallel (master/slave function), and remote control via a communication bus (RS 485 serial port). HEATING HEATING Controls CONTROLS AIR TREATMENT ■■ Total unit protection -- A patented auto-adaptive algorithm controls compressor operation and permanently adapts to the system charac-teristics (water loop inertia). Dangerous compressor cycling is prevented. The unit can operate safely with a low water volume, and this frequently makes a buffer tank unnecessary (see minimum water volume later in this document). -- Pro-Dialog+ permanently analyses the compressor suction and discharge pressures and temperatures. If an abnormal situation is detected, the control reacts, e.g. by reducing the capacity. As a result the compressors always operate in their ideal temperature range and many unit shut-downs due to a fault can be prevented. C A R R I E R 2 0 1 6 / 2 0 1 7 219