tailieunhanh - HVAC and Dehumidifying Systems_7

Tham khảo tài liệu 'hvac and dehumidifying systems_7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Simpo PDF Merge and Split UnregisteredVersion- http a Keep the input and output points to the minimum number required for HVAC control and efficient building operation. Follow the recommended point guidance provided in par. . Follow the principle to Keep it Simple. b Use standard control sequences for similar HVAC control system applications. c Show the following on control drawings as a minimum 1 Flow diagram schematic of each mechanical system showing sensors equipment and operators. 2 Individual point list description for each mechanical system. 3 Electrical ladder diagram for each electrical circuit controlled. 4 Operating parameters - controller setpoints and time schedules. 5 Detailed sequence of operation. d Use direct connection of temperature sensors when possible. Use only precision thermistors 10 000 ohms for room sensing and 1000 ohm platinum RTDs for HVAC unit sensing. e Use room zone temperature sensors with pushbutton override and setpoint adjustment integral to the sensor. f Do not modify the chiller microprocessor system supplied with the equipment. Control and safety functions should be the chiller manufacturer s responsibility. The DDC system should only enable or disable the chiller chilled water pump condenser water pump and in some cases chilled water and condenser water reset. For chillers 150 tons and larger provide an RS-485 communication between the chiller microprocessor and the DDC system. g Do not modify the boiler microprocessor system supplied with the equipment. Control and safety functions should be the boiler manufacturer s responsibility. Design hot water systems to maintain the boiler manufacturer s minimum temperature when in operation but vary the hot water supply temperature as required to meet the building s requirements. 106 Simpo PDF Merge and Split UnregisteredVersion- http h Connect steam high temperature hot water gas and electric meters to the DDC for remote monitoring of energy use