A. THE NEED FOR EMISSION REDUCTION
Life on earth is made possible by energy from the sun, which arrives mainly in the form of visible light. About 30 per cent of sunlight is scattered back into space by the outer atmosphere, but the rest reaches the earth's surface, which reflects it in the form of a calmer, more slow-moving type of energy called infrared radiation. (This is the sort of heat thrown off by an electric grill before the bars begin to grow red.) Infrared radiation is carried slowly aloft by air currents, and its eventual escape into space is delayed by greenhouse gases such as water vapour, carbon dioxide, ozone, and methane.
Greenhouse gases make up only about 1 per cent of the atmosphere, but they act like a blanket around the earth, or like the glass roof of a greenhouse -- they trap heat and keep the planet some 30 degrees C warmer than it would be otherwise.
* Human activities are making the blanket "thicker" -- the natural levels of these gases are being supplemented by emissions of carbon dioxide from the burning of coal, oil, and natural gas; by additional methane and nitrous oxide produced by farming activities and changes in land use; and by several long-lived industrial gases that do not occur naturally.
* These changes are happening at unprecedented speed. If emissions continue to grow at current rates, it is almost certain that atmospheric levels of carbon dioxide will double from pre-industrial levels during the 21st century. It is possible they will triple.
* The result, known as the "enhanced greenhouse effect," is a warming of the earth's surface and lower atmosphere. The IPCC assesses with very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming. The ‘best case’ computer climate models estimate that the average global temperature will rise by 1.8° C to 4.0° C by the year 2100. A temperature increase of 0.74° C occurred last century and for the next two decades, a warming of about 0.2° C per decade is projected should greenhouse gas emissions continue to rise at their current pace and are allowed to double from their pre-industrial level.
* A rise in temperature will be accompanied by changes in climate -- in such things as cloud cover, precipitation, wind patterns, and the duration of seasons. In its Fourth Assessment Report, the IPCC projects that heat waves and heavy precipitation events are very likely to increase in frequency in the 21st century. In a world that is crowded and under stress, millions of people depend on weather patterns, such as monsoon rains, to continue as they have in the past. Changes, at a minimum, will be difficult and disruptive.
* Carbon dioxide is responsible for over 60 per cent of the "enhanced greenhouse effect." Humans are burning coal, oil, and natural gas at a rate that is much, much faster than the speed at which these fossil fuels were created. This is releasing the carbon stored in the fuels into the atmosphere and upsetting the carbon cycle, the millennia-old, precisely balanced system by which carbon is exchanged between the air, the oceans, and land vegetation. Currently, atmospheric levels of carbon dioxide are rising by over 10 per cent every 20 years.
Lighting is one major area of electricity consumption and it is estimated that about 19% of global electricity is consumed for lighting. This comprises of both indoor and outdoor lighting. Manually controlling the lighting circuits is laborious and is prone to errors and unaffordable costs calling for reliable automation systems to save on cost and energy. Dynamically dimming the HID lamps offers an opportunity to conserve more intensely during late night or off peak hours.
The lighting automation offers a substantial scope for conservation and there by contributing to reduction of Green house Gases. Many of the efforts are being recognized under Clean Development Mechanism called CDM leading to grant of Carbon Credits either as CER's or VER's eligible for carbon trading.
B. The problems with earlier photo sensors.
Our information says that a variety of models were tried out in India but the users are unanimous in concluding that these are not reliable. The problems spelt out are
1. The device behaves erratically due to dust accumulation on the sensor window.
2. The device failure due to rain.
3. The device behaving erratically due to clouds and rain leading to switch on of lamps even during the day.
4. The device failure due to over voltages in the mains.
5. The device failure due to short circuit in the load line.
6. The device failure due to thermal factors.
C. The experience regarding timers.
Many timers mostly mechanical type are available in the country and many users have resorted to them as next best solution due to poor performance of light sensor based Automation solutions in India. However due to the inherent conceptual limitations coupled with their poor design approaches the performance of timers is not really satisfactory. Power failure and interruption have also called for resetting of clock in some timer models, which calls for a laborious service that negated the very purpose of Automation. These timers invariably need a contactor to handle a load of even 2 kW thus pushing up the cost. The frequent need to change the setting due to changes in seasons has made them really semi-automatic in the real practice. The only advantage, which a timer enjoys, is that it can be a part of the panel and so the outdoor-induced factors like dust, rain etc are minimized. One factor, which a timer can never solve, is the day to day dynamic variations in a particular season due to factors like cloud cover, rain etc in the evenings or mornings which cannot be predicted in the present state of the meteorological knowledge.
We offer products for two basic functions of switching and HID lamp dimming.
1. Nature Switch family for automatic control of outdoor lighting, and
2. SAVE SWITCH family for late night dimming of HID lamps.
The core objective of all the products lies in Energy Conservation through automation offering the twin advantages of cost saving and emission reduction. We recognize the need to offer solutions to reduce greenhouse gases (GHGs). We are contributing to the above spirit through offering systems for improving energy efficiency in lighting normally called CDM project eligible for carbon credit under the guidelines of United Nations Framework Convention on Climate Change (www.unfccc.int). Nature Switch: The mother of all our products.
This unique product is based on an infrared sensor and the fundamental decision is based on ambient light level for switching ON since it is almost a universal requirement for all outdoor lights. It switches ON the outdoor lights the moment the light level goes below 60 LUX. Once the natural sunlight remains below 60 lux for more than 30 seconds, the NATURE SWITCH will switch ON and ensures that the ground Illuminance of the required level is maintained. Similarly in the morning as the natural light level builds to 10 lux the unit will switch OFF the lamps after 30 seconds so that no more power is consumed unnecessarily. We also offer VISIBLE light sensor based SUN SWITCH for indoor light control.
NATURE SWITCH-01- DUSK TO DAWN CONTROL FREE FROM SETTINGS
This model is called NATURE SWITCH-01 and is particularly suitable to all those outdoor lights, which are ON during the entire night like street lamps, campus lamps, yard lamps etc. The product is offered with extra protective features like OVER / UNDER VOLTAGE sense, trip and auto reset etc.
NATURE SWITCH-02 -A VERSATILE HYBRID SYSTEM.
This model called NATURE SWITCH-02 is specially developed for applications like hoarding control, sign board control etc where normally the users want to switch OFF the lamps late in the night once the normal movement of the traffic slows down say by 11 PM or 12 o' clock in the night depending on the location, city, nature of traffic etc. In fact some of the street lamps can also be switched OFF by say 1 AM in the early hours. For example one phase may be OFF by 11 PM and the second phase by 1 AM and the third phase at dawn depending on the natural light level. These times also change in accordance with the season. Consequently the Nature Switch-02 offers a unique duration based selection for switching off of the lamps. This is expressed in terms of hours from the time of switching ON based on dusk. The selection is possible from 4 to 8 hours with a resolution of half-an-hour. The internal clock is quartz based for long-term stability. Input mains power failure will not stop the clock since a rechargeable battery is provided. This model of NATURE SWTICH-02 also switches on the lights based on natural light level at dusk irrespective of time. The switching OFF will take place as per user selection instead of at DAWN.
SWADEEP 02-EC FOR HIGHER LOADS
NATURE SWITCH models 01 and 02 can handle a direct lighting load of up to 3kW on one phase. It is customary and convenient to use power contactors if the load is more than 3kW. Power contactors are also used for switching load on all the three phases from a common switch. To facilitate an easy installation SWADEEP-02 EC is offered in 6 models. This is an integral model offered with all the control gear, fixing arrangements, cable termination facility, lock and key etc. SWADEEP-02EC is offered as a pole mountable enclosure consisting of a light sensitive control system, power contactor for load switching, MCB, and terminal blocks. The enclosure comes complete with mounting brackets, cable glands, openable door with lock and key. The enclosure is made of UV stabilized, FR grade special molding compound to provide a rust proof, electric shock proof, termite proof, outdoor mountable electrically insulating body capable of enduring solar radiation in the outdoor. Selectable options are available for duration based switching OFF as well Override facility for maintenance
SWADEEP-03-EC-DUAL FOR HIGH MAST
Swadeep-03-EC-Dual consists of NATURE SWITCH®-03 along with Contactor, MCB, Terminals etc. all housed in an SMC enclosure conforming to IP54 along with pole fixing brackets and lock and key. This is specially offered for handling lighting loads like High mast lighting, Street light circuits operating on 3 Phase, Campus lighting etc. The unique feature of this product offers operating partial load for full night and the balance load for part night to derive energy savings. This can also be used on single phase operated street light circuits by running two parallel cables to feed the lighting circuit. Swadeep-03-EC-Dual will switch ON/OFF both the feeding cables run on the same phase to provide a feature of partial load switching OFF during middle of night while the rest of the load runs till sun rise. This is particularly useful in the case of High mast lighting.
NATURE SWITCH® INDOOR: INDOOR LIGHTING CONTROLLER BASED ON LUX LEVEL
NATURE SWITCH®-INDOOR is specially designed for automatic switching of indoor lighting as per the lux level selected. The NS-INDOOR will automatically switch ON the lighting whenever the illumination level falls below the selected level and will automatically switch OFF the lighting load when the natural illumination goes beyond the selected level. It employs an advanced patented Multi Spectral Sensor technology for reliable and dependable operation in the indoors.
NATURE SWITCH®-ATM is designed for automatic control of signage andair conditioner in an ATM, using advanced infrared sensing andmicrocontroller based logic for control of all varieties of air conditioners, which are switched ON/OFF based on the need with attention freeoperation. This reduces manual costs, saves power bills and pays for itself. NATURE SWITCH®-GSM: CONTROL AT YOUR FINGER TIPS
NATURE SWITCH®-GSM offers the NATURE SWITCH® with all its intelligence plus a remote monitoring and communication facility using either a mobile or a web interface as per the choice. An SMS from your mobile handset or a click in our web interface from any Internet enabled device can turn ON/OFF, set ON/OFF timings for your lighting system. The ease of use and accuracy in working makes it a unique product. The device also offers alert messages.
RAKSHA AUTO DIPPER:-
As an experienced and responsible person and having knowledge of road driving conditions, you will agree that night time driving on roads is highly critical and glare is a major problem. Dipping headlamp manually hundreds of times each night demands a lot of time and energy. With focus on steering control one may avoid dipping. Sometimes a few may not dip due to false ego and lack of concern for others. You will agree that automation of the dipping is a better way to improve comfort and safety to all on the road.
RAKSHA® is designed to be universal model. It can be installed in all four wheelers at about 5 feet height from the ground. The product is compatible for 12Vand 24V systems. The product will also be same for low side and high side switching electrical circuits of different automobiles. RAKSHA® consists of two parts. The sensing and processing part will be in the cabin compartment behind the wind shield and the solid state relay will be located in the engine compartment close to the head lamps.
Sensor: RAKSHA®provides you with the latest in automotive electronics using state of the art sensing and advanced Micro Computer. It can think like an intelligent human being and can work like a robot to automate the head lamp beam shifting. RAKSHA®knows when you should travel in high beam and when you can afford to dip your head lamps.
Relay: Automotive headlamp switching is one of the challenging tasks. For many decades automobiles used a simple mechanical switch operated manually to shift the head lamp beam. These switches are designed for smaller wattage of Head lamps. Later mechanical relays have come in to place which are operated by a coil driven contacts. These relays offer only a limited life since the moving contacts have a limited life and in an automotive environment, the lamps are operated many a times each night. This is the genesis for the birth of ‘RAKSHA HEAD LAMP RELAY’ the most revolutionary, unique and ultimate solution based on state of the art technology for the finest service. RAKSHA HEAD LAMP RELAY is based on solid state electronic switching without any moving parts and there is no fuse. There is a built in sense, trip and auto reset for all extremities like over current, over voltage, and over temperature.
Save switch is offered as an intelligent and easy to fix solution for HID lamp dimming during non-peak hours. The product is universal for HPSV and MH lamps and offers dimming upto 40% using the concept of bi-level or step dimming. SAVE SWITCH helps in maintaining the uniformity factor while energy conservation is achieved and the device offers the selection of the peak period duration from 1 to 9 hours. The conceptual basis is provided below for more details.
High intensity lighting is normally provided using HID luminaries like HPSV and MH lamps. They are often the preferred choice when large areas like road ways, parking lots, pathways, etc. are to be illuminated. The power rating of the luminaries is selected based on the Illuminance requirements of the field during the early hours of the night. However the illumination level required will be less during the non-peak hours or during the late night. SAVE SWITCH is designed to meet this need automatically.
Save Switch uses the concept of Step-level dimming enabling wattage reduction to 60% of rated power. Step-level dimming is ideal for saving energy and providing lighting for safety and security during non peak hours. SAVE SWITCH also allows individual fixture control and is suitable for retrofit. Save Switch works with both HPSV and MH types of HID lamp types and is suitable for indoor as well outdoor usage.
SAVE SWITCH comes as a reliable, integrated, aesthetic and cost effective solution with a low pay back period. SAVE SWITCH ensures uniform Illuminance level. SAVE SWITCH is installed in the junction box on a pole for outdoors. SAVE SWITCH comes in series to the input terminals of the control gear. The basic feature of SAVE SWITCH is to maintain the lamp in Higher Wattage (HW) for the selected duration from the time the lamp is switched ON in the evening and to shift the lamp to Lower Wattage (LW) till switched OFF in the morning. Any duration from 0 to 9 hours can be selected.
These are unique in many ways. We shall explain with reference to each of the factors.
1. SENSOR SELECTION
As you agree any Automation involves substitution of human judgment by a device. The intelligence built into the device should be such that its decision must be almost nearer to a rational human judgment by a knowledgeable person in the field. In a Nature Switch the judgment is based on infrared sensor. Consequently the sensor while sensing the solar radiation will not sense the light from most of the normally used outdoor fitted artificial light sources like LPMV, HPSV, HPMV etc since their emission in the infrared spectrum is very negligible for all practical purposes. The ordinary incandescent lamp is the only exception, which in any case is not being used, in large numbers due to their inefficient energy conversion factor. The infrared sensor is also immune to moon light.
The field of view is another important critical design feature, which will determine the normal field sources that are accepted and those that are not accepted. Nature Switch is provided with a carefully selected field of view thus making the Nature Switch not to receive any light emitted by ground-based sources like automobile light or a torchlight etc. Even the light emitted by a lamp fitted to a post on which the Nature Switch is installed will also not reach the sensor. This FOV coupled with the spectral immunity and the level of the signal at 60 lux will for all practical purposes make the Nature Switch to have a highly stable decision making capability regarding the transition from day to night and from night to day. This decision will invariably depend only on natural solar radiation and not the artificial light sources. The near total uniformity of the sky in the post sunset and pre sunrise situation will facilitate the installation of the Nature Switch in any direction like east, west, north or south without any restriction.
The infrared sensor selected for Nature Switch is highly stable in the long run and will not exhibit calibration drift and will be linear up to the point of saturation and will be immune to humidity and temperature. The stability of the device is proved and is assured with the above sensor selection.
2. THE SWITCHING LIGHT LEVEL
The light level selected for judging the switching ON is 60 lux and for switching OFF it is 10 lux. As the generally aimed Illuminance level in most of the outdoor areas as per BIS standards is about 30 lux, the Nature switch will switch ON the lamps on sensing that the natural light level has gone below 60 lux for a continuous period of 30 seconds. With this the artificial lamps are switched ON at the appropriate time. For switching OFF, a level of 10 lux is appropriate since human visibility will build to a satisfactory level even at 10 lux in the early Dawn. The model with timer will switch OFF the load after the selected duration instead of waiting till dawn.
3. CLOUDS, RAIN AND OTHER FACTORS
One may have a feeling that clouds, rain, fog, mist etc will make the Nature Switch to misjudge the ambient levels and leads to switch ON even during the day. Nature Switch is constructed in such a way that the sensor is sealed in a container to the standards of IP 65. The presence of cloud, rain, fog, mist etc during the time when the sun is above the horizon will not make the ground Illuminance fall below 60 lux. This can happen only after the sunsets or before the sunrise. Consequently no erratic switching will occur in Nature Switch.
4. THE DYNAMIC JUDGMENT
The actual timing of switching should logically be decided based on a dynamic situation, which is influenced by atmospheric conditions, which may vary not only by seasons but also on each day. The timing based switches known as timers cannot really address the issue in view of their fundamental limitation of going by a preset time which may or may not meet the actual field requirements. The infrared sensor based Nature Switch with total immunity but capable of responding to the dynamic variations is the most appropriate and unique solution.
5. THE EFFECT OF DUST
There may be a genuine feeling that dust present in the general atmosphere and the high degree of the same in busy streets, factories etc will get accumulated on the sensor window and will make the switch to behave erratically. The other devices tried out in the past were having design limitations with regard to dust prevention. Nature Switch is designed is such a way that the sensor window is part of a vertical wall and the material used for window construction is having anti static properties to repel the dust particles. The normal forces of wind and water will remove the small layers and so the device performance will not drift drastically on account of dust.
6.THE EFFECT OF SHADES
The other question usually raised is the effect of fixing the device under the shade of trees and sunshades. While the tree will block a major portion of sunlight in the midday it's effect in the dawn and dusk times will be very less in view of the fact that light will be reaching from all directions of the sky almost with the same intensity. The Nature Switch will switch ON or switch OFF the lamps only when we do not find any shade of a tree. But however a tree shade will have an impact in terms of a slight shift in the timing of operation of the device. The real difference in terms of time may be as low as 1 second to a high of 5 minutes.
7. FITMENT HEIGHT
The suggested height for fitment is 6 feet from the ground so that the normal pilferages and unwanted handling by passersby will be eliminated. This will also make the sensor not to receive the mud splashing from a moving traffic in the rainy season.
8. ELECTRONIC DEVICES-- RELIABILITY
The general failure of electronic devices occurs due to many factors like water, corrosion, high voltage, thermal damage, component failure etc. Nature Switches are housed in an insulated molded engineering plastic container sealed to IP 65. This is to ensure that no atmospheric contaminants like moisture; corrosive chemicals etc will not enter the circuit area. The internal thermal generation is as low as less than 1 watt and the same is carried away to the ambient by the metal terminals. Each of the electronic components is capable of performing up to 80 degrees centigrade. The thermal elevation at the hottest spot in the circuit will be a maximum of 20 degrees. So the device can perform continuously in an ambient of up to 60 degrees centigrade while the highest open-air temperature ever recorded on the surface of the earth is known to be only about 54 degrees.
9. INPUT VOLTAGE AND LOAD CURRENT
The Nature Switches do not have a transformer, which is a cause for many known failures, and a continuous voltage of even up to 440 also cannot damage the circuit. Surges and spikes in the mains voltage are suppressed with specially chosen varistors. The overload trip and latch mechanism will protect the device and also the load circuits from high load currents, which can occur due to many factors beyond the control of, even the user. The device is also provided a special provision of over voltage detection and trip and auto reset. Similarly low voltage also is detected. The device will be stable and can perform in a voltage range from 120 to 440 Volts AC though the load is tripped at below 150 volts and above 280 volts for protection.
The device was tested at full load of 16Amps for 5000 cycles, which means an operation for 5000 days, which is about 14 years. The sparks across the power switch contacts at the time of switch OFF is minimized with special components.The overload trip circuit trips the over current on the power switch automatically. The current is measured continuously by a non-series sensor, which is calibrated for reliability.
10. THE OPERATIONAL STATE AND LED INDICATION
The operational state of the Nature Switch should always be clear to the user. This is facilitated by an LED, which changes its color as per the state. Green, Amber and Red are the three states of the LED. LED also flashes for in different colors to indicate that the Nature switch has tripped the load and the reason for tripping is indicated by the color of the flash of the LED.
The construction facilitates an easy installation with the help of two screws. The total weight is less than 400 grams, which can be easily suspended. The terminal box is designed to ensure easy access and at the same time to provide isolation. The terminal box is molded by using flame retardant grade plastic materials with good mechanical properties. A neoprene rubber based shroud will prevent the insects like ants etc from coming in contact with the live cables. The SWADEEP 02-EC is designed to be installed as an integral system and the product comes with all the needed fixing brackets etc. SIGN SWITCH is designed to be installed at the time of manufacture of the signage itself.
12. ELECTRICAL CONNECTION AND THE CONTACTOR
Nature Switch is intended as a direct substitute to an existing manual switch. It does not need a contactor if the connected load is less than 16 Amp. If the load is more, the same can be handled with the help of a contactor like all the present timer based installations. If a contactor is used in a single-phase installation of more than the rated load or in a three-phase installation of any load the Nature Switch will only drive the coil of the contactor, which will handle the actual lamp load.
We wish to conclude by saying that the Nature Switches were designed keeping in view the field requirements and they have proved their reliability and utility.