Basic Solar Technical Training Manual

Transcription

1 Basic Solar Technical Training Manual Prepared by: February

2 CONTENTS 1. Solar Home System Components The User Solar Panel Battery Charge Controller Load Sizing a Solar Home System Installation Maintenance & Servicing

3 1. Solar Home System Components 1.1 The User The user is the most important component of the solar home system. This is because, he or she is the end user of the system, pays for the system & maintains this system. When a person buys a motorbike, he is the user (driver) & he obviously keeps track of the performance & usage of this bike to limit his/her cost. A solar home system user is very similar to a motorbike user in these aspects. Although he can only do so if he/she has the knowledge regarding the optimal use of the solar system. Steps towards a satisfied client: 3

4 User Needs: Before installing a system, always talk to the user to identify & quantify his/her needs. Well Sized Systems: Ask the user about his/her usage of the various appliances he will be running on the solar home system & the duration of usage as well. Quality Components: Assure the user that the components of this solar system are of a good quality & present to him the offer in terms of services provided, warranties and after sale services. Quality Installation: A long lasting and reliable system is to be installed which can run for a long period with minimum maintenance. Quality Training: The user should be provided with information and training about the solar home system, right from the installation to the minimum maintenance techniques which they can perform as well. After-Sale Services: Try to provide locally based technicians for servicing of the systems. Following these steps would provide a good relationship with the user 4

5 1.2 Solar Panel A solar panel (PV module) is a device that produces a flow of electricity under sunlight. When the sunlight is bright, the power produced from the Solar Panels is high and when the sunlight is less (cloudy days), power produced from the solar panels is also less. Cells, Modules and Arrays When sunlight strikes a PV cell electrical current is produced. As each photovoltaic cell produces only about 0.6 volt of electricity, cells are often mounted together in groups called modules. Each module holds about forty photovoltaic cells. By being put into modules, the current from a number of cells can be combined. When multiple PV cell modules are put together, they can form an arrangement called an array or array field. Larger the area of a module or array more is the electricity produced. *Note: Solar Panels always produce Direct Current. This electricity from the panels is used to charge batteries, but a few PV Systems can be used without batteries as well.(example: Solar Water Pumps). To power normal household electrical devices (A.C powered) an inverter is required because solar panels produce only D.C Power. Most solar panels have an aluminium frame, with a glass top, and are waterproof. They do not rust and have a long life of 15 years and above. 5

6 A junction box is present on the back of the module that has two cables coming out of it for electric connection (shown left). Module Characteristics Behind every module, there are electrical characteristics as shown in the figure on your left. These characteristics describe the performance of a Solar PV module. Maximum Power Pmax It is the maximum power delivered by the panel. Open Circuit Voltage Voc It is the voltage obtained from two terminal of a panel Short Circuit Current Isc It is the current obtained from two terminals of a panel in short circuit Maximum Voltage Vmp It is the maximum voltage that the solar panel delivers at STC* conditions Maximum Current Imp It is the maximum current value that the solar panel delivers at STC* conditions 6

7 Standard Test Conditions STC Ambient Temperature 25ºC, Solar Radiation= 1000W/m 2 What is series or parallel combination of panels? 1.3 Battery Need for a Battery: The panel produces current during the daytime but we need the electricity at night. So in order to utilize the electricity at night time it is necessary to store the current. Also during cloudy days, the solar panel cannot provide enough current. When this occurs, the appliances run primarily on battery power. Battery is such a device, which can store the current. That s why a battery is an essential part of a solar system. Battery is the 7

8 bank of a solar system. Inside a battery there are metal plates placed in the solution of sulphuric acid. Lead acid battery is normally used in a solar system as shown below Battery Characteristics The function of a battery is to provide stored current when the solar panels are not producing current (Ex: Night-time). As discussed previously, the unit of current is Ampere. Bigger the battery capacity, more is the amount of Amperes the battery can produce for a longer duration of time. The capacity of the battery is measured by ampere-hour. Ampere-hour can be obtained by multiplying total ampere and time (hour). Ex: A 50 Amp-hour battery can draw 50 amp for 1 hour (50amps X 1 hour) A 50 Amp-hour battery can draw 10 amp for 5 hour (10amps X 5hour) OR 8

9 Battery Charging and Discharging: When a battery is charged by a solar panel, the process is called charging and when the Electricity is taken out of the battery then it is called discharging. The efficiency and the life of a battery depend on proper charging and discharging. Charging and discharging level depend upon the type of the battery. For solar applications we always use deep discharge batteries. For these batteries we can extract 70-80% of battery charge at once without any damage to the life of the battery. This means that from a 100 amp-hour car battery we can take a maximum of 70-80amps. After this the battery has to be charged again. Otherwise the life and efficiency of the battery will deplete fast. If a battery discharges more than the normal, then it is called overdischarging. Over-discharging limits the life of the battery. How to Make the Battery Bank When two or more battery are connected in a system then that is called battery bank. In this case the batteries are assembled in series and parallel as per requirement. If the required output voltage is 12 volt and more current (more capacity) is needed then batteries are connected in parallel. For example: If we connect two batteries having capacity of 12 volt, 100 amp-hour in parallel then the voltage of the battery bank will be 12 volt but capacity will be 200 amp-hour. 12V 100Ah 100Ah 12V = 200Ah, 12V 9

10 If we need more voltage, then batteries are connected in series. For example, the above mentioned batteries are connected in series. The voltage will be 24 volt and the capacity remains same. 12V 100Ah 12V 100Ah = 100Ah, 24V The Description of the Liquid used in a lead-acid Battery: There is a solution of sulphuric acid and water in each cell of the battery. The specific gravity of the solution is This means that the liquid becomes 1.25 times heavier than water. This specific gravity should not go down below 1.15 and should not exceed Heat is produced while making this type of solution. This solution is poured to the cell after bringing the temperature by keeping in the air to room temperature. In a solar home system the battery is charged by the solar panel. Battery is discharged when operating an electrical appliance. Electrolyte The liquid inside the battery cell is mixture of water and sulphuric acid is called electrolyte. 10

11 Hydrometer It is an instrument which is used to measure the specific gravity of the liquid inside the battery. This specific gravity is a measure of the charge inside the battery. How to Use: a. The hydrometer consists of 2 glass tubes. 1 small glass tube is placed inside the bigger tube. Red White Green 1100 R 1125 E C 1150 H A R 1175 G E F A 1250 R 1275 G O O 1300 D b. The big rubber plug at the top is squeezed and placed inside the cell of the battery. The straw of the hydrometer should be touching the electrolyte when squeezing is done. c. Leave the rubber plug then and due to suction, the liquid is sucked inside the hydrometer. d. The test tube inside starts floating and the reading of the inside tube at the highest point of the liquid is the specific density of the electrolyte. Note: a. Ensure that there is sufficient electrolyte inside the cell when placing the hydrometer inside. b. If the liquid inside the tube falls even when there is no squeezing, this means the hydrometer has a fault and should be replaced. The table above describes the charge of the battery depending on its specific gravity. Also it describes the next step to be taken in case the battery charge is less. 11

12 How to examine a battery In a full charge battery the cell voltage would be 2.2/cell. i.e. a 12-volt battery has 13.2 volt in full charge condition. In this situation the specific gravity of the battery would be in the range of So to determine the overall condition of the voltage and the specific gravity of the battery is measured by a voltmeter and a hydrometer respectively. Scale Reading Battery Status Solution Charge very less Charge the battery For 7 days without use Charge less Charge the battery for 3 days without user boost charge Charge is good No action required Highest Charge No action required Note that the quantity of liquid is reduced then only pure water has to be poured. In no circumstances, acid or acid mixed water should be given. The Effect of the Battery on Environment: Recharging In solar electrical system battery plays a very important role. Battery gets continuously discharged while driving the load. Hence the battery needs to be charged with proper voltage and current for re use. this called re charging. We discuss below the 5 process of recharging. Constant current Recharging :This is a simple process of recharging. a 100 AH battery is re-charged with 10 amp. current. Constant voltage recharging: In this process the charging voltage is fixed to volts DC.(For 12 v Battery) at the start battery takes a high charging current and it comes down continuously after the battery gets fully charged. Boost Re charging: For quick recharging boost recharging is required. Here the charging current can be upto ampere. For 12

13 boost recharging the battery should not be over discharged and charging temperature should not be more than 43 degree centigrade. Float recharging: Sometimes battery cannot take the load even if the specific gravity of the liquid is perfect. At this stage the battery is charges through 3 amp. charging current which is called float re charging. Precaution. 1. Charging and discharging of batteries are followed by generation of inflammable gas. Henceforth it is recommended not to put any item causing fire beside the battery. 2. Avoid short circuit of the battery causing explosions. 4.For Connecting battery with the system at first connect (+) and then (- ).For disconnection at first open (-) and then (+). 5. Don t run any system without charge controller which will affect the longevity of the battery. 6. Avoid using too many connections or junctions which will result more power consumption. 7. If the battery is kept unused for a considerable time get it charged on monthly basis. 8.No maintenance should be undertaken if there is a strong smell of sulphuric acid in the vicinity of the battery bank 9. No smoking or naked flames 10. Safety goggles MUST be worn 11. Acid resistant gloves MUST be worn 12.Acid resistant apron or clothing should also be worn 13. Clean water should be available near the batteries to wash any acid that comes in contact with skin 14. Bi-carbonate soda should also be available to be used, with water, to neutralise any acid that is spilled onto the ground 13

14 15. The ends of spanners (or any other tools) that you will use near the battery bank should be insulated to avoid any accidental shorts between the terminals 1.4 Charge Controller What is a Charge Controller? A Charge controller controls the flow of current to the battery. It balances between charging and discharging. When the battery is fully charged during day time, the controller stops charging.at night when the solar panels stops producing current, the voltage drops to a certain level, the controller puts off the appliances. The charge controller undertakes the above function automatically. The charge controller acts like the brain of the system. It is connected to the solar panel, battery and appliance. It is a very important part of the system as it determines when to start the battery and when to start the panel current. Why use a Charge Controller? Batteries are sensitive to both over charge and under charge. The battery is charged by the panel every day. If the stored power in a battery is greater than the daily consumption of this power,the battery will get over charged. This will damage the life of the battery. If the stored power is less than the daily consumption of power then the battery will be over discharged which will adversely affect its life. A simple diagram of the complete circuit is shown below. 14

15 Characteristics of Charge Controller: Above seen is a charge controller, it can be seen that the Panel, Battery and Appliance have different connections from the charge controller. There are also 2 lights. 1 light is ON when the charging from the panel is going on and the other lamp is on when the battery power is low indicating that the appliance is going to be switched off if the battery is not charged soon. In a charge controller there are two cut-off points which are as follows: Upper cut off point : 14 volt volt Lower cut-off point: 11.2 volt-11.4 volt 1.5 LOAD Load is a device which consumes electricity when it is connected to the battery. It can be a light, a fan a television or any device that runs on electricity. Characteristics of Loads 1. Loads need to be energy efficient 15

16 2. The efficiency of the load has to match the purpose where it is used. For example, if it is a light, its Lumen* output per watt has to be as high as possible acceptable (usually above 40 lumen/watt). (*Lumen- It is a measure of intensity of light) A.C Load Loads can be AC or DC type. The loads which require AC voltage to operate are called AC load like most Colour TV, Ceiling fan etc. AC load will require the use of an inverter. This unit will need to highly energy efficient and affordable. AC loads should be avoided in SHS to reduce system size and costs. D.C Load The loads which require DC Voltage to operate are called DC loads such as black and white TV, car fan etc. Certain loads are being operated by both AC & DC. The voltage required to drive a load depends on the design of its control circuit Inverter As mentioned before, the current produced from a solar panel is purely direct current. (D.C) But most of our daily appliances use Alternating Current (A.C) Ex Fan, Light, Television, Computer. No A.C appliance can be operated using the Direct Current. An inverter is a device that converts the D.C electricity of the solar panels to A.C electricity. 16

17 2.Sizing a Solar Home System Sizing a solar photovoltaic is done to match the correct number of panels and batteries to produce power with the correct number of appliances which consume this power for a certain period of time. Every solar panel can produce only a limited amount of power depending on the amount of sunlight on that particular day and the panel capacity. Hence an exact estimation of load is very important before sizing the system. The steps in sizing a system are shown below. 17

18 Load Estimation The first and most important step in sizing a solar photovoltaic system is the load estimation. The entire system design depends on load estimation. If the load estimation is not correct this would result in: a. High initial costs: Extra cost of panels and batteries if the system is over sized. Electricity produced is wasted. b. Array / battery is too small: If less number of panels and batteries used then the system Is undersized. This will result in loads not running for desired durations and batteries running out quickly. c. Leads to system failure Hence it is very important to measure load demand for accurate information. For D.C devices: DC load demand = DC load Current (Amps) * hours of operation Note: If DC load is given in Watts, then, DC load current (Amps) = DC load Power (W) / Nominal DC Voltage Use this value in the above formula then. For A.C devices: AC Load demand = AC load Power (Watts) * hours of operation 18

19 Daily Load Sizing For DC Loads: D.C Loads Quantity * Amperes* Hours/Day= Daily Demand (Ah) Dc Loads (Ah) = For AC Loads: A.C Loads Quantity* Watts* Hours/Day= Daily Demand (Wh) AC Sub-Total (Wh) = For AC loads it is also important to choose an inverter. Efficiency of the inverter Is an important factor which is used in load sizing. Most domestic inverters available have an efficiency of Also important for load sizing is the input voltage. For systems of capacity less than 2000Wh/day, 12V is taken as the input voltage. (This factor depends on the battery voltage) Daily Load (Ah) = DC Load + [AC Total/ (Efficiency*Input Voltage)] As the efficiency and input voltage of the system are always constant: Daily Load Demand ( Ah ) = DC Load + (AC Total/10.2) 19

20 Note: a. If the system has only A.C Load b. If the system has only D.C Load Daily Load (Ah) = (AC Total/10.2) Daily Load (Ah)= DC Load Note: Please be very careful when sizing. a. Be sure to include all the loads which will be running by the Solar Panels b. If extra appliances are to be plugged in to the solar system, make sure to size the system for that appliance as well. c. Although it is tough to provide the correct number of hours of operation of each device, it is very important to get this data correct, so it is advisable to give a higher number of hours of operation from the average usage. Radiation Estimation Estimating the amount of solar radiation at a location is very important to continue the sizing process. Depending upon the amount of solar radiation falling on a place, the amount of electricity that can be produced is estimated which helps in determining the number of panels and batteries. Peak hours of sunlight for the lowest solar radiation month is required to estimate radiation for sizing a Photo Voltaic System. This data can be found from the table below Location Lowest Radiation Value Asansol 4.11 Alipore (Kolkata) 3.83 Alipore (Dum Dum) 3.65 Contai 4.05 Darjiling 3.82 Dhulian 4.06 Durgapur

21 Kharagpur 4.09 Koch Bihar 3.94 Shantipur 4.09 Shiliguri 4.02 Depending on the closest region to the site of installation, choose the lowest radiation value. This value will be utilized later in the sizing process. Module Sizing Solar panels are sized according to the worst month of the year so that the system is operational even during this month and obviously every other month. 1.Number of Parallel Modules = Daily Load Demand (Ah) /Module Daily Output(Ah) We have already found the daily load demand in our previous calculation. To determine Module Daily Output (Ah) is: Module Daily Output= Columbic Efficiency*(Module Output*Derating Factor) Module output = Peak hours * Imp of module As discussed previously, Peak hours can be selected from the table given above. Imp of the module is the maximum current delivered by it. This value can be found behind the panel under the electric characteristics. The columbic efficiency and the derating factor are panel losses. Both these parameters are recorded to be 0.9. Module daily output = Peak hours * Imp of module *

22 Note: With the help of this calculation, the number of parallel modules to be installed can be determined. If the module number value is in decimals, always round it off to the next digit. 2.Number Of Series Modules = System Voltage / Module Voltage System Voltage depends on the appliance. Most simple appliances running on D.C like fan, CFL have a voltage of 12V. Always check the appliances for the highest voltage value so that the sizing can be done correctly. Module Voltage for small capacity panels is mostly 12 V. It is always recommended to check the module voltage before calculating the number of modules required. Thus module sizing is completed. The combination below shows a combination of 2 series of modules with 5 panels in parallel for each series.hence a total of 10 modules 22

23 Battery Sizing Battery Sizing is based on the days of autonomy (number of days the system can run without the solar panels producing any power). More the days of autonomy, more has to be the number of batteries in the system. For residential applications, we mostly use the value for days of autonomy to be three. As mentioned above, we never discharge the battery completely. A maximum discharge of 75% is permitted to protect life of the battery. This value is called Maximum Depth of Discharge or DoD = 0.75 Battery Capacity (Ah) =( Days of Autonomy*Daily Load)/Maximum Depth of Discharge All these values can be found form the previous readings. Number of Parallel Batteries= Battery Capacity/Individual Battery Capacity Once the battery capacity is found, we choose a battery system. ( Batteries of different Ampere hour capacity are found in the market). If the battery number value is in decimals, always round it off to the next digit. Number of Series Batteries = System Voltage/Battery Voltage This calculation is similar to the previous calculation of the number of series panels. Please check the battery voltage before calculating this value. 23

24 3.Installation How to Install a Solar Home System The following aspects should be kept in mind to install a solar home system: 1. Installation of Panel: Selection of a suitable place: Following 4 affairs should be considered while selecting suitable place for installing a panel: a. Abundance of Light: Panel should be installed in such a place where direct sunlight falls on it (panel). As sunlight runs the solar panels, if the place does not receive ample sunlight, the power produced from the panels will be less, hence leading to the failure of the system. b. Angle of placement of panel Solar panel is installed facing south at 23 0 alignment with ground. The idea to place the panel at certain angle is to take an average angle of the sunlight throughout the year that is from January to December to avoid placement of panel at different angles at different time to get more electricity. This angle is 23 0 degrees. 24

25 c. The effect of Shade/ light on panel Care should be taken so that shade does not fall on the panel. Shade or barriers of sunlight cause less efficiency of the panel. That is the capacity of producing electricity is reduced and effects adversely on the electricity production. d. The distance between the Panel and the Battery The distance between the panel and the battery should be kept in close as far as possible. The distance should exceed 40 ft. It will be better to keep the distance between ft. Because the capacity of this electricity is low and quantity is also less, higher is distance between the panel and the battery the more is the voltage loss. This means that the loss of electricity will be more and as a result, the efficiency will decrease. 2. Installation of Controller Controller is the brain of a solar system and it is an automatic device. It protects the battery from over charging and over discharging and increases the efficiency of the battery. So the controller should be installed in a place as close as possible to the battery. Above all it should be installed in a place from where the performance can be constantly observed without any difficulty. The controller should be installed first in the system. 3. Installation of Battery Battery should be installed at a safe place near the controller where there should be sufficient air flow. Before installation the following aspects should be taken care of: 25

26 a. Always keep the battery horizontal b. Insulated instruments should be used while working with battery c. Battery must be kept in an airy & dry place 1. Installation of Lighting System The lights should be placed in such a way that all areas of the room are lighted equally to present a beautiful look. The distance from the controller and the switch of the lamp should not exceed ft. Always keep the switch and the lamp beyond the reach of the children. 2. Wiring The efficiency of the system depends upon its wiring. So special care should be taken in wiring. The wiring should be simple and limited as per specification laid down in the diagram. All wire connection should be done correctly. It should be kept in mind that a perfect wiring increase the beauty of a room as well as increases the efficiency and life of the system. On the other hand wrong wiring can severely damage the system 3. Selection of Cable We know that solar system is a limited capacity system. The voltage drop/ system loss in a solar system should not exceed 2%. Appropriate cable should be used to reduce the loss of voltage and to make the system work with optimum efficiency. House Wiring All load (including all appliances) should be parallel with the battery as shown in figure and the switch should be connected in series. Never connect the load in series. Because if the load is connected in series then the voltage is shared with the loads. Power does not reach at every load as a result no load shall operate. The following diagram shows the mode of making perfect wiring Lamp Lamp Lamp TV Figure: The connection of load with battery 26

27 Lam Lamp Figure : Never connect the load as shown in diagram above Guidelines for Installations For installation of solar home system the guide as indicated below needs to be followed. The complete electrical connection of a SHS is shown below. Panel Battery Load

28 Connection procedure for Battery, Panel and Load at a glance. 1. Battery & charge controller has to be connected as per the polarity of the battery. 2. Panel & charge controller has to be connected as per the polarity of the Panel. 3. Load & charge controller has to be connected as per the polarity of the load. For disconnection of charge controller start removing with load followed by panel and battery at last. Connection between Battery and charge controller Connect positive end of the battery to the positive terminal of the charge controller. Connect negative end of the battery to the negative terminal of the charge controller. Panel Battery Load

29 Connection between Panel and charge controller Connect positive end of the panel to the positive terminal of the charge controller. Connect negative end of the panel to the negative terminal of the charge controller. Panel Battery Load Connection between Load and charge controller Connect positive end of the load to the positive terminal of the charge controller. Connect negative end of the load to the negative terminal of the charge controller. Panel Battery Load

30 The steps for Installation of system 1. First a wiring diagram should be drawn at a place of installation of system. An example of such a diagram is shown below Panel Switch Lamp Lamp Switch Controller Junction Box Switch Switch Lamp TV Socket Battery 2. Panel should be installed in a open place of a house to receive profuse sunlight from dawn to dusk. 3. According to the diagram first install the controller. Care should be taken so that the distance between the panel and controller does not exceed 40 feet. 4. Battery should be connected to the controller. 5. Using a test lamp, check whether the connection is ok. 6. After this, the panel should be connected with the controller 7. At last connect the lamps, TV and other appliances with controller 30

31 4.Maintenance & Servicing Maintenance of a Solar Module 1. Clean Clean the solar panel with a piece of soft cloth once in 15 days. Panel cleaning should be done early in the morning as the metal frame containing the panel gets hot rapidly with the advancement of day. 2. Not covered - Ensure that the panel is not covered by any dust, image of tree or TV antenna. 3. Secure - Keep the panel in a secured place when you have a forecast for abnormal calamities like cyclones, fires etc. 4. Ventilation - At the time of fixing the panel on the terrace arrange for proper ventilation under the panel. Maintenance of a Battery 1. Install the battery in a dry and clean place and ensure proper air circulation. Don t cover it with anything 2. Clean - Clean the plastic cover of the battery with a clean dry cloth 3. Maintain the electrolyte of the battery at the upper level. If you find a reduced level of water in a cell please increase the level. 4. Don t connect any load from battery terminal directly. This will shorten the battery life. 5. Ensure that the Specific gravity of the battery liquid never falls below 1290 at the time of charging. 31

32 6. If the the battery is kept discharged for a long time, battery plates have sulphate accumulation on it and the battery gets ineffective. 7. It is recommended to measure the specific. gravity of the battery liquid on regular basis with hydrometer and check the level of the battery electrolyte. 8. In case of flood and rain it is recommended to place the battery under a shed so that it is not unaffected by water. 9.The positive and negative terminals of the batteries needs to be lubricated by grease or petroleum jell. 10.The battery needs to be charged and discharged on half yearly basis to ensure the longevity and effectiveness. 11.If the specific gravity of the electrolyte comes down below 1200, the battery needs to be charged with the panel and don't apply any load during charging. 12.Check the specific gravity of the electrolyte with hydrometer on regular basis. 13. Check the connection of the battery terminals and tight the bolts and nuts if required. 14. Clean the vent plug of the battery by mineral water. 32

33 Preliminary test before connecting the battery. 1. Check whether the electrolyte labels in each labels are same and above the lower label. 2. Check whether the specific gravity is between 1240/ Ensure the battery to be charged before connecting in the system. The recommended battery Voltage should be at least 12.8 volts DC. 4. Acid can burn the skin or the cloth. 5. Never take the fire close to the acid of the battery because that can cause fire. 6. When the battery life ends it should be returned to the manufacturing company or buried under the soil. The remains of a battery can pollute environment. 7. Never burn the battery. System Maintenance a)charge controller do not require any maintenance b) Connecting cables needs to be checked from time to time so that they are not getting snapped. c)ensure that there is no accumulation of dust over the panel.charge controller do not work if the electricity is interrupted. d)battery terminals needs to be greased or to be lubricated by veslin to avoid corrossion. Since the controller is being operated by the battery, uninterrupted current flow needs to be ensured. e) Shut down (turn off) all loads on the system starting from the household appliances and working back to the inverter. 33

34 f) Disconnect the solar panel. g) Shut down the battery bank this would involve either switching off circuit breakers or removing any fuses on the battery bank. If fuses are used, the fuse on the negative terminal of the battery bank should be removed first followed by the fuse on the positive terminal. h) If a switch-fuse is used, opening the switch fuse disconnects the fuses from the batteries. Maintenance of Charge Controller. 1. Clean - Clean the charge controller with a soft piece of cloth on occasional basis so as to avoid the accumulation of dust. 2. Fuse - Ensure the fuse is of correct rating. Maintenance of Light and Wiring: 1. Clean - Clean the lamp shade and its glass case with cloth on regular basis which will ensure bright illumination. 2. Check for any breaks or deterioration in exposed conduit and wiring. Also inspect connections for any signs of corrosion and/or burning. If any damage is noticed contact the system supplier/installer. Inspect the condition of the conduit and wiring from the: Solar Panel to charge controller charge controller to battery bank Inverter to battery bank Inverter to AC switchboard 34

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