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ELECTRICAL INSTALLATION WORKS
SECTION - 16511
LIGHTING CONTROL SYSTEMS
The Contractor shall supply, install, test, connect and commission fully programmable microprocessor based architectural and intelligent Lighting Control System for control of lighting circuits in the Main Entrance, Lobbies, Foyers, Periodicals, Hotel Reception Multipurpose Hall and other public areas. The system shall be complete with, but not limited to, all necessary Lighting Distribution Panel Boards, Modular Switching Assemblies, Centralized Preset Lighting Controls, Software, PC, cabling, containment system etc. and any other components and accessories deemed essential for high quality high performance state-of-the art Lighting Control System, all in strict compliance with these Specifications and relevant details in drawings. Some spaces, as shown in the drawings are controlled by using occupancy sensor, stair cases are controlled by motion sensors.
1. GENERAL.
1.1. Detailed load schedules for dedicated lighting distribution boards for each
specific area shall be provided by the sub-contractor in compliance with design lighting layout. The load schedule shall be complete with particulars of each outgoing circuit with respect to type and number of lighting luminaries and control zones.
1.2. Three No. dedicated Intelligent Lighting Control Panels, designated ILCP1,
ILCP2 and ILCP3 have been specified for control of lighting circuits in specific areas as indicated in the drawings
1.3. The switching schedule shall be designed to offer switching ON/OFF of
lighting points in a pattern to be advised by the Engineer/Client at site. If necessary, circuits and number of lighting points in respective circuits may be altered to suit switching requirements.
1.4. All installation works shall be carried out by experienced personnel in strict
compliance with the instructions and guidelines provided by the manufacturer.
1.5. The Contractor shall be required to provide full two year warranty and limited
five year warranty on all equipment supplied and installed in the system.
1.6. Prior to placing the order for the Lighting Control System, the Contractor shall
submit revised circuits, load schedules complete with full technical details of the system and components offered, for Engineers study, comments and approval.
1.7. Upon completion of the installation, the system shall be completely tested and
commissioned by manufacturer’s Engineer. All lighting load and control circuits shall be tested live to check for continuity and freedom from defects.
1.8. Prior to handing over the installation, the Contractor shall be required to make
arrangements with the Manufacturer to train Client’s designated personnel in the understanding of the system capabilities, its correct operation and maintenance schedules and requirements.
SPECIFICATIONS ELEC/SPEC.16511.
File: ELECSPEC16511.doc
Lighting Control Systems
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2. OCCUPANCY SENSORS
How does an occupancy sensor work?
The general answer is that occupancy sensors work by detecting human presence or activity. The specific answer is that occupancy sensors use one or more of three different technologies to detect or "sense" human presence and/or activity.
The most common technology is passive infrared (PIR). A PIR sensor works by sending out invisible infrared beams that read or respond to temperature differences. If there is no one in the range of the sensor the sensor does not respond. When a warmer object, such as a human body, crosses two or more beams the sensor responds to the difference in temperature between the person and the background. This is the technology used in basic security sensors. In the case of a basic security sensor, there will be typically 4 - 10 beams which mean each beam is fairly wide. This is why you can sometimes walk directly towards a security sensor and nothing happens. It is because you are moving within one beam and not crossing two beams. Only when you cross at least two beams will the sensor activate.
In modern PIR occupancy sensors there can be over 1400 individual beams which make them much more responsive to small movements such as sitting at a desk and typing on a keyboard. PIR works very well in most commercial environments and can detect at a long range, up to 40 meters, in warehouses and underground car parks. PIR has several limitations, however; it requires line of sight and will not read through any material including glass. In addition, PIR does not work well in extremely warm environments as it cannot distinguish between the temperature of the human body and the background.
The second common technology is microphonics. As the name implies, occupancy sensors that incorporate microphonics work by picking up noise that is typical of human occupancy or activity. Advanced microphonics sensors incorporate Automatic Gain Control (AGC) and can "learn" background noises such as the steady hum of a central air conditioner or the sound of a circulating fan. They are also sensitive enough to pick up sounds typical of human activity such as typing on a keyboard, talking on the phone, a phone ringing, tapping on a desk, a chair squeaking, walking on a wood floor and numerous other sounds that are typically generated by human presence or activity. Microphonics type sensors do not require line of sight and can hear around corners. This type of sensor works very well in large open plan office and commercial areas as they can cover a large area without having to "see" all of it. The limitation of microphonics sensors is that they do not work in very noisy envorinments such as a factory or where a recurring noise not necessarily related to human activity such as a TV that stays on in the background or an individual, window type air conditioner that comes on and off whether there is a person in the room or not.
The third common tecnnology is high frequency (HF) ultrasound or ultrasonics sensors. HF works exactly the same as a bat's "radar" or a submarine's "sonar." The sensor sends out a high frequency sound wave that bounces around the space and returns to the sensor. Any movement that disturbs the wave activates the sensor. HF sensors can be very sensitive and can read through many materials including the most commonly used interior construction materials and glass. From a human occupancy standpoint, HF's big limitation is that it responds to any motion, not just
SPECIFICATIONS ELEC/SPEC.16511.
File: ELECSPEC16511.doc
Lighting Control Systems
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human presence. For example, an open window and rustling curtains or a moving window shade or, in an office environment a piece of paper coming out of a printer, can activate an HF sensor even if no one is there.
To enhance the strengths and minimize the limitations of each of the three
technologies, sensor manufacturers sometimes combine technologies in "dual
technology" sensors that typically include a combination of PIR and either microphonics or HF.
The most important issue for a successful occupancy sensor installation is to understand the strengths and limitations of each type of sensor and to choose the appropriate sensor for the application. Occupancy sensors can save significant amounts of energy and take the human factor out of remembering to turn off the lights, the air conditioner and any other equipment that only needs to be on when there is human presence.
RECOMMENDED MANUFACTURERS
1. LUTRON, USA.
2. CLIPSAL, Australia.
3. ABB, EU.
SPECIFICATIONS ELEC/SPEC.16721/16770.
File: ELECSPEC16721/16770.doc
Analogue Addressable Voice Integrated Fire Detection and Alarm System
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