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ABC of BMS.pdf

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ABC of BMS.pdf

  1. 1. Simplifying BMS Design
  2. 2. by Ashwini Karkara BAS Consultant & Engineers
  3. 3. Building Management System-: Begin with the basics BMS – Building Management system Building Automation system A Building Management System (BMS) is a blend of hardware & software based is a blend of hardware & software based control system installed in buildings to control and monitor the building’s mechanical, electrical & other utility equipment
  4. 4. Building Services Services Equipments Mechanical system HVAC , Plumbing , Fire Fighting, STP Electrical System Electrical DB’s/Lighting control & monitoring, Generator set, UPS Utility & Life Safety Lifts, Fire Alarm System,
  5. 5. Tenant Billing Maintenance Management System Access Control AC System Ventilation and Exhaust Air System Public Address & 2-Way Communication System Fire Detection and Control System Generally the Systems Controlled and Monitored By BMS IBMS Central Monitoring Access Control System Lighting Control System PHE System Electrical/ DG/ UPS System Elevator System Central Monitoring Systems Asset Tracking System / TAM System CCTV and Security System
  6. 6. Basic of Instrumentation • Us our Body and its parts • Our Body Reflexes
  7. 7. In BMS INPUTS:- Sensors Temperature (of room) Humidity (of room) Flow Rate (chilled Water) Flow Rate (chilled Water) Pressure (of Fire Hydrant) Level (of a Tank) Run status (Pumps, Fans)
  8. 8. Temperature Sensors – Sensing technologies • Thermistor – Accurate over limited range – Point type only – Used for space temperature • Nickel Wire – General purpose sensor – Point or averaging type – Used for space or duct – Application Issues • Mount inside thermal well for water temperature • Mount return air sensor away from fresh air stream • Mount space temperature sensor : – At 1500 mm height – On inside wall – Away from direct sun or other heat sources • Ensure off-coil sensors are far – Used for space or duct • Platinum – High accuracy / linearity – Point type only – Precision applications • Ensure off-coil sensors are far enough away from coil • Outdoor air temperature sensors require sunscreen • Calibrate using precision resistor, validate using digital thermometer • Know mounting scope of responsibility
  9. 9. Pressure Sensors – Air Static Pressure • Used to control VFD based on VAV duct static • Must be mounted in region of laminar flow; five duct diameters from restrictions • Active sensor – Water Static Pressure • Used to monitor pressure at top of sprinkler riser • Commercial grade sensors can leak – Water Differential Pressure – Air Differential Pressure • Used to calculate airflow from velocity pressure – PVELOCITY = PTOTAL - PSTATIC – CFM = 4005 * AREA * (PVELOCITY / K FACTOR)½ • Used in VAV boxes and air flow monitoring stations – Water Differential Pressure • Used to control bypass valve or VFD • When controlling bypass, best to mount at last AHU • Do not try to save costs by using two static pressure sensors • Calculation error of same magnitude as signal may ocur.
  10. 10. Other Sensors  Waterflow  Mount in region of laminar flow; five diameters from restrictions  Many technologies:  Annubar  Paddlewheel  Carbon monoxide  Control car park ventilation fans  Carbon Dioxide  Used as indirect indicator of indoor air quality  Paddlewheel  Electromagnetic  Turbine  Humidity  Used to measure the Relative Humidity in air.  Some humidity sensors comes with in built temperature sensors also. indoor air quality  Electrical Transducers  Current Transducers  Voltage Transducers  Lux Level Sensors  To measure the intensity of light.  MOTION SENSOR
  11. 11. In BMS OUTPUTS:- Control Valves VFD Speed Command Air Dampers Actuators ON-OFF Command (Fans, Pumps, Boilers)
  12. 12. INPUTS & OUTPUTS INPUTS e.g Analouge (varying-reading) AI Temperature, Humidity, Water Flow , Air Flow , Tank Level, Energy KW, Voltage, Current, Pressure, pH, Conductivity Digital (Binary-ON or OFF) DI or BI Status (on/off, airflow , run, open/close) Alarm Trip Trip OUTPUTS e.g Analouge (varying-positioning) AO Fan Speed regulating (0 to 100%) Chilled water valve control (0 to 100%) Digital (Binary-ON or OFF) DO or BO Command (on/off, open/close)
  13. 13. I/O Building management system relies on 4 types sensory information to make a control decision Analog inputs : are used to read a variable measurement. Examples are temperature, humidity and pressure sensor which could be thermistor, 4-20 mA, 0-10 volt or platinum resistance thermometer (resistance temperature detector), or wireless sensors. Digital input : indicates if a device is turned on or not. Some examples of a digital input would be , an air Digital input : indicates if a device is turned on or not. Some examples of a digital input would be , an air flow switch, or a volt-free relay contact. Analog output : controls the speed or position of a device, such as a variable frequency drive, a I-P (current to pneumatics) transducer, or a valve or damper actuator. An example is a chilled water valve opening up 25% to maintain a setpoint. Digital outputs : are used to open and close relays and switches. An example would be to turn on the parking lot lights when a photocell indicates it is dark outside. A typical Mid Size Building may have 800 -2000 sensory points also known and I/O points. A complex Building like an Airport may have more than 5000 points
  14. 14. DDC Controllers  Types of DDC controllers  Fixed function  Configurable  Text programmable  Graphic programmable  Point Definition  Ranging (linear, calculated,  Control Loops  Proportional plus integral control commonly used  Other software routines used in local control logic  Minimum, maximum, average, calculator, etc.  Psychometric calculations  Timing (delays, pulses, etc.)  Ranging (linear, calculated, polynomial)  Filtering (smoothing and debounce)  Interlocks  Timing (delays, pulses, etc.)  Boolean and comparator operators  Time clock and backup schedules
  15. 15. DDC physical
  16. 16. Outputs Analogue Inputs The Controller maths logic PID Alarms Times Logs Time control for boilers, chillers etc. Modulating or on/off valves Analogue Temperature Pressure Humidity Digital Run / fault Pulsed Meters
  17. 17. Control System
  18. 18. Case Study IIT ROORKE
  19. 19. Operation Screen
  20. 20. Light & AC BMS Screen
  21. 21. Typical BMS for Lighting Control Sl. No IO Description AI DI AO DO FIELD DEVICE 1 Room Lights Circuit 1 &2 & 3 On/Off 0 0 0 2 To the 6Amps light phase of each circuit 2 Room Motion Status 0 1 0 0 Dual PIR Sensor to sense motion 3 Room Lux level 1 0 0 0 Room Mounted Lux Level 4 Room AC start/Stop 0 0 0 1 To Window AC electrical starter panel 5 AC Run Status 0 1 0 0 Current Switch across Window AC phase. TOTAL 1 2 0 3
  22. 22. Control Logic for Lighting Control • Based on the Time Schedule for occupancy the BMS DDC shall switch on the room lighting. • Same logic operates only if Occupancy sensor senses any motion in the room. any motion in the room. • The LUX level of room is sensed and based on high lux level the room light circuits (nearest to windows) are switched on first and then if lux level still increases the second circuit is switched OFF.
  23. 23. AC BMS SCREEN
  24. 24. Control Logic for AC Control • Based on a Time Schedule AC phase can be allowed to pass through the AC starter. • AC run status shall be monitored through a current switch which shall provide a contact in case AC switch which shall provide a contact in case AC compressor is taking load .
  25. 25. Tanks and Pumps
  26. 26. Typical BMS for Water System Sl. No IO Description AI DI AO DO FIELD DEVICE 1 Ground Tank Low , Medium and High Level 0 3 0 0 Level Switch in underground tank 2 Raw Water Pump On/Off 0 0 0 1 Through Raw Water Pumps starter 3 Raw Water Pump Auto/manual Status 0 1 0 0 Through Raw Water Starter Panel Auto/Manual Switch 4 Raw Water Pump Run Status 0 1 0 0 Current Switch across Pump phase. 5 Overhead Tank Low , Medium and High Level 0 3 0 0 Level Switch in overhead tank. 6 Transfer Water Pump On/Off 0 0 0 2 Through transfer Water Pumps starter 7 Transfer Water Pump Auto/manual Status 0 2 0 0 Through Transfer Water Starter Panel Auto/Manual Switch 8 Transfer Water Pump Run Status 0 2 0 0 Current Switch across Pump phase. TOTAL 0 12 0 3
  27. 27. Control Logic for Water System • The Ground Floor Tank Low , Medium and High Levels are measured. If ground tank level is between Low to High the raw water pump is switched on till it achieves High level. • If Overhead tank level is between Medium and Low level the transfer pump shall be switched on to fill the overhead tank till level is High. • Failure of any pump shall automatically switch on the standby pump.
  28. 28. Fire Alarm Screen
  29. 29. Gas Suppression Screen
  30. 30. Energy Monitoring Screen
  31. 31. Diesel Generator Screen
  32. 32. AIR HANDLING UNIT SCREEN
  33. 33. Typical BMS for AHU Sl. No IO Description AI DI AO DO FIELD DEVICE 1 AHU On/Off 0 0 0 1 AHU panel to accept 2A NO contact 2 AHU Run Status 0 1 0 0 Differential Pressure Switch across blower 3 AHU Auto/Manual Status 0 1 0 0 Pot . free contact @ AHU Panel 4 AHU filter Status 0 1 0 0 Differential Pressure Switch across filter 5 Return air temperature 1 0 0 0 Duct type temperature sensor 6 2 Way chilled water modulating valve control 0 0 1 0 2 way Modulating Valve 7 Chilled water return header flow rate 1 0 0 0 Flow meter TOTAL 2 3 1 1
  34. 34. Inputs to the Controller:
  35. 35. Outputs from the Controller:
  36. 36. EXHAUST FANS
  37. 37. AC CHILLER PLANT
  38. 38. What is a Building Automation System?  A BMS system collects the operating information required for intelligent building management.  It analyses the operation of the building systems by viewing all important temperatures, humidities and equipment status.  Further to collection of these data, the BMS presents these data on the screen with full color • Automates some control strategies such as turning equipment On/Off according to a time schedule – ensures energy savings • Allows an operator sitting at the BMS work station to view key information about the building – improves building operations the building – improves building operations • Allows an operator sitting at the BMS work station to control some of the equipment in the building – improves building operations allowing remote control / over-ride where necessary • Maintains an audit trail of what happened and when it happened – improves building management by means reporting and traceability • Maintains historical data for selected information (like temperature, humidity ..etc) – improves building management by means reporting and traceability • Alerts the operator at the BMS work station when readings fall outside of normal range (i.e. breaker trips, temperature too warm, etc.) – improves building management by having a faster reaction time to problems • By doing the above and more a BMS system saves manpower, ensures productive occupants (especially in an office environment), prolongs equipment life, and the most important of all saves energy. diagrams (graphics) for the ease of understanding.
  39. 39. BMS Protocols BMS system manufacturer divided predominantly into two different protocols, mentioned below- • BACnet - A Data Communication Protocol for Building Automation and Control Networks developed by ASHRAE. It gives freedom to client to connect all BACnet compliant devices and ease in commissioning & configuring. configuring. • Lonworks -Lon Works is actually a family of products originally developed by the Echelon Corporation. At the core of this technology is a proprietary communications protocol called Lon Talk. Here one needs to buy license for each individual controllers & devices. Commissioning requires software key (dongle) all the time for commissioning & configuration. • Modbus is developed by Modicon in 1979. It is used to establish master- slave/client-server communication between intelligent devices. It is a de facto standard, truly open and the most widely used network protocol in the industrial environment and devices.
  40. 40. System Architecture IP- 1 Tier Where all controllers are connected to HMI on LAN. TCP/IP Server Bacnet over IP 963 Software with Bacnet Protocol Client Client DDC 1 P1-service DDC 2 P2-service DDC 3 P3-service Sub Station Control Room Portable Operator Terminal P1- Gnd Third Party Integrator for APFCR relays, ACB, DG switchgear, BTU, multi data meter, KWH meters, VFD, Chiller, DG, UPS, Boiler & Jet fan 3rd Party 3rd Party 3rd Party P1- 2nd flr P1- 3rd flr P1-4th flr P1- 5th Flr P1-Upper Basement P1-Lower Basement P1- 1st flr Multi protocol integrator DDC 1 DDC 1 DDC 7 DDC 1 DDC 1 DDC 9 DDC 1 DDC 11 DDC 1 DDC 1 DDC 2 DDC 1 DDC 2 DDC 3 Hotel Mall Office
  41. 41. DDC 1 Lower Ground (Pump Room) System Architecture. Server DDC 4 Diesel Generator (LT Room- Ground Floor) DDC 2 &3 Lower Ground Floor (Lighting Control) Main Supervisory Controller (EINC) Supervisory Software 963 DDC 5 & 6 Electrical (LT Room – Ground Floor) DDC 4 Diesel Generator (LT Room- Ground Floor) DDC 7 &8 Ground Floor (Lighting Control) DDC 9 & 10 First Floor (Lighting Control) DDC 11 &12 Second Floor (Lighting Control) DDC 13 ( Terrace Tanks) & DDC 14 (Fire Hydrant)
  42. 42. RS 485 – 2Tier Level1-: where all controllers are connected to each other in daisy chain fashion & then after they connect to router or gateway. Level2-: When router or gateway is connected to any HMI for monitoring & controlling. to any HMI for monitoring & controlling.
  43. 43. Building Automation System Software Alarms User Interface and Password  Energy Operations Maintenance Supervisory Controller (processing) Operator Workstation (long term storage) Operator Workstation Where this feature resides      Control Logic Demand Limiting and Duty Cycling Historical Data Graphics Scheduling  Supervisory Controller DDC Controller Supervisory Controller Operator Workstation Supervisory Controller Supervisory Controller (processing) Operator Workstation (long term storage)             
  44. 44. BMS Typical BOQ- It can be categorized in 3 broad categories- 1. BMS controllers, Softwares, POT(Portable Operator Terminal),integration & PC. 2. Field Devices- It comprises different kind of sensors, switches, actuators, Transmitters etc switches, actuators, Transmitters etc 3. Cables & conduits
  45. 45. 1. BMS controllers, Software's, POT (Portable Operator Terminal), for integration & PC. • Controllers selection can be done based on the IO (Input Output) requirements directly just to match AI(Analog Input), AO(Analog Output), DI(Digital Input), DO(Digital Output) in the layman’s language. • Integration to collect the data from different devices.
  46. 46. 2. Field Devices- Comprises different kind of sensors, switches, actuators, Transmitters BMS Areas Category Type Sub- Category Application AHU(Airside) Temperature(cum Humidity/RH) Sensor Room To know the actual Temp inside without cooling Duct To know flowing air Temp(& RH) inside duct for supply & Return Air Differential Pressure Across AHU Fan to check it is on or off physically, Differential Pressure Switch Air Across AHU Fan to check it is on or off physically, across filter to check the status Valve & Actuators Across cooling coil Chillers, cooling towers(Waterside) Temperature(cum Humidity/RH) Sensor Immersion To Know water temperature from the chillers & to the chillers Outside To Know outside temp & RH Differential Pressure Switch Water Across Pumps to check it is on or off physically, across filter to check the status Others Level Transmitters Water To know the water level Oil To know the oil level CO2, CO sensor Room To know the air quality as in parking lot
  47. 47. 3. Cable It generally can be categorized in two different applications-: • Signal/Control Cable: From different field devices to controllers & from Controllers to field devices to control the equipments • Communication Cable: cable between different controllers, routers & gateways for the purpose of intercommunication between & gateways for the purpose of intercommunication between controllers. • Integration cable: cable required for monitoring of third party devices.
  48. 48. Cable Selection BMS Areas Category Cable Type Application AHU Duct, Room Temp sensor 2c x 1 sqmm shielded Passive Temp(2c) signals from sensor to controllers Temp cum humidity sensor 4c x 1sqmm shielded Passive Temperature(2c) & Active(2c-power) RH measurement from sensor to controllers DP Switch for Air 2c x 1 sqmm shielded Passive Temp(2c) signals from switch to controllers AHU FAN VFD 2c x 1 sqmm shielded Run status 2c x 1 sqmm shielded On/off status 2c x 1 sqmm shielded Relay output for VFD On/OFF Operation Valve & Actuator 5c x 1sqmm shielded Control & Power (3c power and command) & Monitor (2c)
  49. 49. Integration BMS Areas Category Cable Type Application Integartion DG 2c x 1.5 sqmm twisted pair shielded Integration is only to collect data from different devices to monitor & generate reports UPS 2c x 1.5 sqmm twisted pair shielded Integration is only to collect data from different devices to monitor & generate reports VAV's 2c x 1.5 sqmm twisted pair shielded Integration is only to collect data from different devices to monitor & generate reports 2c x 1.5 sqmm twisted pairIntegration is only to collect data from different devices to monitor Electrical Panels 2c x 1.5 sqmm twisted pair shielded Integration is only to collect data from different devices to monitor & generate reports Chillers 2c x 1.5 sqmm twisted pair shielded Integration is only to collect data from different devices to monitor & generate reports Security & Fire Alarm system 2c x 1.5 sqmm twisted pair shielded Integration is only to collect data from different devices to monitor & generate reports Elevator 2c x 1.5 sqmm twisted pair shielded Integration is only to collect data from different devices to monitor & generate reports
  50. 50. BMS Design Aspects Basic data required before you start system design: 1. Input / Output summary for all subsystems, which need to either monitor or control. 2. Selection of appropriate field devices. 3. All integration devices & respective point details which has to be monitored. 4. Signal & Communication cable route layout (at least tentative). 5. Panel (Enclosure for controllers) location, BMS PC location. Steps to follow for designing-: 1. Select the suitable controllers required for the requirement. 2. Select the enclosure to mount those controllers, which includes power supply for controllers & other wirings for field device connection. 3. Now start with the AHU designing which includes signal & control cabling requirement for different field device selection as per the requirement. 4. A typical AHU generally requires following field devices-Temperature cum Humidity sensor (or only Temp) in return & supply duct. Differential Pressure Switch (For Air) across the AHU Fan, Filter, Actuators for AHU Line. 5. A typical AHU will have following wiring connection- Connection to all Field devices, Connection to electrical panels as per I/O, connection to VFD’s. 6. A typical Chiller side will have following field devices-Immersion type temperature sensor (for supply & return pipes), Butterfly Valve & Actuator in each chiller supply, differential Pressure sensor across main supply & return . 7. A typical chiller will have connection to all field devices, chiller panels, Pump VFD’s.
  51. 51. BMS Commissioning Aspects – Air Side Commissioning- It comprises individual commissioning of AHU (Air handling Unit), CSU (Ceiling Suspended Unit), Fans & associated field devices. • We need to measure each field devices value during AHU commissioning as first task to make sure all field devices are working & then all points can be put in a logic. Water side commissioning – It comprises individual commissioning of Water cooled chillers, Air cooled chillers, Cooling towers, Primary pumps, Secondary pumps, VFD’s & associated field devices devices • We need to measure each field device value & other connected points value individually before putting them into logic. Integration of Air side & water side in a logic-This is to integrate all independent system in logic. Which can work automatically based on the user defined parameters without any conflict of individual system functionality.
  52. 52. BMS Commissioning Aspects Integration of monitoring points- • This is to collect all data in BMS system for the purpose of monitoring only. • PICS details i.e mapping details to be taken from respective equipment supplier. • Protocol significance for integration purpose-whenever we say one device supports Modbus over RS485, here RS 485 signifies physical channel (cable type) & communication port while Modbus signifies data pattern. Therefore all devices in a loop must support same protocol & configure to the same. • Cable used for integration is 2 core x 1.5 sqmm shielded • Cable used for integration is 2 core x 1.5 sqmm shielded • All monitored devices have to be looped in daisy chain connection to RS-485 port. Devices can support different communication over different protocols. We need to make sure whenever making a loop all devices should support same communication & protocol type. for instance Modbus over RS485. Client User interface (UI) • Client can change parameters as temperature & humidity from UI as per the comfort level & all basic information can be viewed on the UI.
  53. 53. SNAPS OF INSTALLATION
  54. 54. PANEL
  55. 55. SCHEMATICS-AHU
  56. 56. SCHEMATICS-TFA
  57. 57. SCHEMATICS-SCRUBBER
  58. 58. Water Tank
  59. 59. EXHAUST FAN
  60. 60. CHILLER
  61. 61. CHW & CDW PUMPS
  62. 62. COOLING TOWER

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