ABSTRACT
A Building Management System (BMS) is a computer based control system installed in buildings that controls and monitors the building’s mechanical and electrical equipment in the most efficient way.
Benefits
• Switches plant on and off automatically according to time, time of day and environmental conditions (e.g. senses conditions and activates devices to correct settings)
• Optimizes plant operation and services • Monitors plant status and environmental conditions and thus improves standards of operation and main-
tenance • Allows remote access, control and monitoring (e.g. using graphical information and alarms)
Types of BMS points
• Is the physical connection of a BMS point to a controller or outstation I/O terminals? The points schedule is critical when designing the system
• Input – gathers data/monitor; Output – provide command/control • Analogue points – has a variable value 0% to 100% (e.g. temperature sensor, modulating control valves) • Digital points – binary I/O (0 or 1) (e.g. on/off control, run/off/fault status) • Network integration points (NI) – allows to communicate or integrate to stand alone controller such as chiller,
meters, boilers, generators
BMS Components – hardware and software/programming
Hardware
• Primary network/BMS backbone – Head end equipment (desktop computer, laptop, monitors, keyboard, dot matrix and colour printer,
UPS supply, etc.) – Ethernet Network Cabling (normally Cat 5e or Cat 6 cables) – Ethernet switch (located inside the control panels)
• Secondary network – Control enclosure (CE) or Control panel (CP) or BMS outstation – Motor control centre (MCC) – Unitary controller for FCU/VAV/Chilled beams – Power cables and isolators (from MCC panel to mechanical equipments) – Control cables (from MCC/CE panel to field devices) – Field devices (control valves, meter, sensors, VSD/Inverter, DOL starter, star-delta starter, actuators)
Software/programming
• BMS programme protocol – Refers to the communication of BMS from PC software to the different types of controller/sensors (e.g. Modbus, LonWorks, BACnet)
• Graphics – Provide true representation of the installed plant. Colour graphics shall incorporate automatic updating of real time field data
• Software System Integration (e.g. energy management system, chillers, boiler, CHP, generator, water treatment plant, closed control units, blind control, lighting control, security and access controls)
office
Shell and Core:
1. Head end equipment (Workstation) Extra cost: Additional remote workstation
£10,000-£20,000 £5,000-£10,000
2. Network connection (BMS backbone – Copper) £15,000-£30,000
3. Main plant – cost per BMS points Factors that affect the cost: UPS and touch pad display for each control panel Panels enclosure – fire-rated or GRP enclosure
£525-£840 per pt
4. Control enclosure (CE) for future tenants. Additional I/O modules will be part of fitting out cost Factors that affect the cost: UPS and touch pad display for each control panel Panels enclosure – fire-rated or GRP enclosure
£5,000-£10,000 per panel
5. Landlord FCUs – depending on points per/FCU controller Factors that affect the cost: Local controller for cellular office, meeting rooms, etc.
