Water-Cooled Condensers - HTS

installed, high interrupt current rated, non-fused disconnect switch withthrough-the-door handle. Each circuit shall be equipped with factory-installedcompressor isolation circuit breakers.OPTION: The unit shall have a high short circuit rated panel with single pointpower connection to a factory-installed, high interrupt current rated, non-fuseddisconnect switch with through-the-door handle. Each circuit shall be equippedwith a factory-installed compressor isolation circuit breaker.The control system shall stage and load the compressors based on the leavingwater temperature. Equipment protection devices controlled by themicroprocessor shall include motor protection, high pressure, loss of refrigerant,loss of water flow, freeze protection, and low refrigerant pressure. Controlsshall include auto/stop switch, chilled water setpoint adjustment, anti-recycletimer, and digital display with water temperature and setpoint, operatingtemperatures and pressures, and diagnostic messages. The following featuresand functions shall be included:1. The control logic shall be designed to maximize operating efficiency andequipment life with protections for operation under unusual conditions.The system shall intelligently stage the unit to sustain leaving watertemperature precision and stability while minimizing compressor cycling.2. The following features and functions shall be included:a. Password protection for setpoint adjustment.b. Durable liquid crystal display (LCD) screen type, having minimum four20-character lines with 6 key input pad conveniently mounted on the unitcontroller. Default language and units of measure shall be English and I-P respectively. Messages shall be in plain English. Coded messages,LED indicators and LED displays are not acceptable.c. Remote reset of chilled water temperature using a 4-20mA signal.d. Soft-load operation, protecting the compressor by preventing full-loadoperation during the initial chilled fluid pull-down period.e. BAS communication through Open Choices. Optional modular pluginsthat enable the unit controller to communicate using standardizedprotocols such as LONTALK, Modbus and BACnet without aseparate gateway.f. Non-volatile program memory allowing auto-restart after a power failurewithout requiring a UPS (un-interruptible power supply).g. Recording of safety shutdowns, including date-and-time stamp withsystem temperatures and pressures. A minimum of six previousoccurrences shall be maintained in a revolving memory.h. Start-to-start and stop-to-start cycle timers, providing minimumcompressor off-time while maximizing motor protection.i. Lead-lag compressor staging for part-load operation by manual selectionor automatically by circuit run hours.j. Pro-active compressor unloading when selected operating parametersexceed design settings, such as high discharge pressure or lowevaporator pressure.k. Diagnostic monitoring of unit operation, providing a pre-alarm signal inadvance of a potential shutdown, allowing time for corrective action.H. The following options are to be included:Chilled water flow switch to be field mounted in the chilled water line andfield wired to terminals in the control panel.58 WGS 130A – 190A Catalog WGS-1