Solar PV systems Users` maintenance guide
Contents
1. Battery bank log sheet Date Date Date Name Battery voltage Ambient temperature Cell 1 SG Electrolyte temperature Corrected SoC Cell volts Water used in litres Cell x SG Electrolyte temperature Corrected SG Cell volts Water used in litres Interconnections OK Battery cases OK Comments G66 S G SG C C C C S C c 666966066 66666666666666666 666666 Balance of systems log sheet Date Date Date Name Battery voltage Regulator tem clean nsects removed Cables connections OK Functioning OK nverter tem clean Insects removed Cables connections OK Functioning OK Battery Charger Item clean Insects removed Cable connections OK Functioning OK Control Board Item clean Insects removed Cable connections OK All switches circuit breakers operate correctly OK Cables conduits mechanically OK Electrical connections OK Comments Note Tick when OK Also if there are other generating items eg wind generator then the log sheet should include space for all regulators2. Time VVeather Comments 40 9 9 9 9 9 nverter log sheet Date Name Cleaned No Cable nverter Comments inverter insects connections operating OK correctly 9 BOS log sheet Date Name Cable All Cable Meter Comments connections switches connections operating OK and 5 OK correctly operating Annex 3 Glossary 41 Annex 3 Glossary 240V 240 volts a lethal voltage AC alter
3. 9 9 9 9 9 Genset log sheet Date Name Genset Oil Fuel Oil Air Comments total hours changed filter filter filter run Note Ticked when changed 9 9 9 9 VVind generator log sheet Date Name ntegrity Bearings Mechanical Electrical Comments of tower lubricated integrity wiring structure changed of blades integrity amp tail pesueyo suono uuoo p yo q p yo q p
4. If you suspect that the genset is not operating correctly call your system supplier installer or your service mechanic Wind generators Pico hydro generators The basic components of a pico hydro system are shown in the diagram below With most pico hydro generators the maintenance required will be specific to the machine and pipe installed The user manual should always be consulted before attempting any maintenance The intake system should be designed to minimise the blocking of the inlet pipe by leaves sticks or silting up If this is a problem then the main maintenance on a pico hydro system will be keeping the intake system clean and free of debris With most wind generators the maintenance e check that system regulators and dump required will be specific to the machine and loads are functioning in windy conditions tower installed refer to system supplier if things don t look right The wind generator is typically located on a tower Most of the maintenance that will be required on the wind generator will require the tower to be lowered Typical checks by the system owner e inspection of guy wires on guyed tower check for tension and excessive fraying or corrosion of guy wires e check the functioning of any manual furling mechanisms e if a cable twist system is used check the amount of twist and untwist if required and WATER STORAGE INTAKE SYSTEM The water flow
5. can be controlled automatically PIPELINE CONTROLS x az ISOLATING To Load VALVE GENERATOR To stream TURBINE m SHUNT LOADS 14 Solar PV Systems Users maintenance guide 2 Battery bank The battery bank usually consists of individual 2V cells connected together in series and sometimes in parallel to provide a battery bank with the required system DC voltage and energy storage Sometimes 12V or 6V monoblock cells are used instead of the 2V cells These systems should use batteries which are designed for deep cycling applications which are better suited to the charging and discharging regime Car and truck batteries are not suitable The battery bank should be housed in an enclosure accessible only to authorised people An authorised person could be the system owner or an appointed person In Australia there are two main types of batteries used in SPS systems Wet cell flooded batteries vented cells in which the electrolyte level must be regularly checked Sealed or gel cell batteries where there is no access to the electrolyte a regulated valve is incorporated and the battery is completely sealed Nickel cadmium NiCad and nickel iron NiFe batteries are rarely used for solar power systems in Australia General installation requirements The batteries should be located in accordance with manufacturer s recommendations The battery b
6. y y p soliqni S S USLULUOD 60 10 3 9014 S lZZON 2 5 yeul wey ajeq 9 9 9 9 9 9 Pico hydro log sheet 38 Solar PV Systems Users maintenance guide Annex 2 GC maintenance log sheets Solar array log sheet Date Name Cleaned Array Array Array Array modules structure cabling cabling output OK mechanical electrical voltage Array output current 9 9 9 9 9
7. All safety switches residual current devices RCDs which detect current leakage to earth should be tested by pressing the test button provided As part of your system inspection the switchboards and visible wiring can be Residual current device RCD Battery chargers The maintenance required for battery charging equipment is similar to that required for inverters voltage of the genset if volt meter has been installed If genset is not producing correct output voltage then the battery charger will not operate correctly If the genset is OK then contact system supplier installer clean dry and ventilated area When inspecting the charg ing equipment remove any excess dust from the unit and especially from any heat sinks This should only be done with a dry cloth or brush Check that the charger does charge the battery bank when the genset is operating If it does not appear to be operating correctly check the output Any battery charging equip ment should be installed in a System wiring 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 e charging source to its regulator e regulator to battery bank e inverter to battery bank e genset to battery charger e battery char
8. a pole or structure damage caused by rotating and or moving parts an accident while lowering or raising of tower e damage by stumbling into unfenced or unprotected guy wires e being hit by tail in sudden wind gusts if structure tower is suitable for climbing To minimise the hazards the following precautions should be taken when undertaking any maintenance e follow all recommendations provided in the equipment manuals and e use a brake on turbine before lowering or raising tower or e use a qualified service technician The hazards related to pico hydro generators can include the risk of e electrocution due to dangerous voltages either DC or AC LV e falling whilst accessing pipes in steep and slippery locations and e accidents caused by rotating and or moving parts To minimise the hazards the following precautions should be taken when undertaking any maintenance e follow all recommendations provided in the equipment manuals and e turn off water source or e use a qualified service technician umma 9 3 Maintenance schedules and logbooks A maintenance schedule with an equipment logbook or logbooks should be provided as part of the documentation supplied to the system owner by the supplier at the completion of system installation and commissioning Suggested maintenance intervals and records for major equipment components of an SPS or GC system are provided in section
9. an equalisation charge should be performed and the battery bank rechecked Using a hydrometer to check the specific gravity of the electrolyte in a battery bank Before use thoroughly rinse all components of the hydrometer to avoid contami nation of the electrolyte by foreign materials Also rinse and clean the thermometer Choose one cell for the measurement of the elec trolyte temperature Insert the thermometer into a cell being careful not to touch any plate or other internal battery structures Leave the thermometer in the elec trolyte while measuring the specific gravity of the other cells in the battery bank Hydrometer Completely deflate the bulb of the hydrometer and insert the tube into the electrolyte releasing the bulb to draw up the electrolyte Specific gravity measurement To measure specific gravity a hydrometer is used A glass thermometer is used to measure the cells temperatures Generally the electrolyte is drawn up by the hydrometer and a specific gravity reading is taken from the float level A typical deep cycle cell which is fully charged will have a specific gravity of approximately 1 250 at 25 C Confirm the value for your battery from the system supplier or battery manufacturer A reading less than 1 250 indicates a lower state of charge within the battery The thermometer is required because the specific gravity changes with temperature A higher temperature
10. are not excessively hot typically early in the morning After the modules have been cleaned a visual inspection of the modules can be done to check for defects such as cracks chips and discolouration If any obvious defects are found note their location in the system logbook so these can be monitored in the future in case further deterioration affects the modules output When inspecting the solar modules the condition of the array mounting frame should also be noted Items to observe should include the array mounting bolts eg bolts rusting and checks to ensure that the frame and modules are firmly secured 12 sotar pv systems Users maintenance guide Gensets A petrol LPG or diesel genset will require regular checks of the fuel and oil levels These will need to be topped up as required In addition regular servicing including complete oil changes and filter changes will be required at intervals specified in the system manual t is recommended that all gensets do at least have an AC volt meter on the output so the output voltage can be monitored If the genset is generating a voltage higher or lower than the typical 240V 230V or operating faster or slower than the recommended speed the genset could damage household appliances while the associated battery charger could also be damaged or not operate correctly There should also be a run hour meter to determine when maintenance is due
11. baking soda to enter the cell even a tiny amount of baking soda will permanently damage the cell Checking the charge and condition of the battery bank There are two methods for determining the state of charge and condition of the battery bank They are e measuring the voltage of each cell e measuring the specific gravity of the electrolyte in each cell The measuring of specific gravity is the more accurate measure of a cell s state of charge when used in con junction with manufacturer s specifications and data Frequent recording of the specific gravity of your cells can be part of their warranty requirements terminal then from the positive terminal If the battery bank contains more than one string of cells each parallel string should have its own circuit breakers or switch fuses to isolate each parallel string as described above The battery bank is now electrically isolated from all energy generating devices and loads It can now be worked on for maintenance BUT remember each cell is an energy storage device shorting of any terminals is dangerous and can cause an explosion 20 solar Pv Systems Users maintenance guide Voltage measurement Once the battery bank is isolated use a volt meter to measure the voltage across the complete battery bank and across each cell and record in the logbook If any cell is more than 10 higher or lower than the average cell voltage
12. data sampled by the user low voltage LV 120V DC 50V AC or greater pico hydro generators converts kinetic energy in water to electrical energy microprocessor using computer chips modules photovoltaic cells connected in series and sometimes parralel to provide required power monoblock battery cells connected in series and located in one case often provided as a 6V or 12V battery eg same as in your car noise can damage ears open circuit voltage across PV array when there s no load parallel electrically connected side by side photovoltaic electricity produced from the sunlight RCD residual current device regulators controls the current to the batteries remote monitoring reading data in another location using a modem remote starting ability to start the genset from a remote switch residual current devices circuit breaker triggered by an electrical short to earth rusting can be caused by galvanic reaction between dissimilar metals series electrically connected in a line SG specific gravity shorting when two opposite charged terminals or cable eg and are connected together shunt electrical current bypasses the load and is supplied to an alternative load specific gravity density relative to water SPS stand alone power system not connected to the grid stand by mode inverter is switched on waiting for a load terminals positive and negative battery connectors tower structur
13. decreases the specific gravity a lower temperature increases the specific gravity of the electrolyte To convert your actual measurement to a value at the standard temperature of 25 C a correction factor must be applied This information will be supplied in your battery manual Some manufacturers supply graphs showing the relationship between specific gravity temperature and effective state of charge Measure the specific gravity of electrolyte in each cell see above and record in the logbook Apply the temperature correction to the readings and check with battery data to estimate the state of charge If the specific gravity measurement of any cell is more than 0 025 below the average specific gravity of the battery bank then an equalisation charge should be applied and the battery bank rechecked Thermometer with stopper B Stand alone solar PV systems 2 1 isdi hubir hur cal ve iS nal suni ini kan mur riexiroiyin q specific gravity Squeeze the bulb and deflate squirting electrolyte carefully back into cell electrolyte Neutralising acid spills To neutralise an acid spill use a solution of baking soda and water Mix half a cup of baking soda in approximately 10 litres of water For larger spills use a mop to clean up the spill This solution can also be used for cleaning the cells and battery terminals Reading the electrolyte Re
14. if provided or on the floor indicating a possible battery leak or overfilling condition of battery containers and e battery voltage level B Stand alone solar PV systems 1 7 Charging your batteries To maximise the life of a battery bank it is best to ensure that it is regularly receiving a full charge and that its state of charge is not allowed to fall excessively Please check the manufacturer s recommendation with the system supplier some solar lead acid batteries can go down to a maximum depth of discharge of 70 80 while for some deep cycle lead acid batteries the recommended maximum depth of discharge is 50 Each day at around the same time the battery voltage should be checked as this will give you a regular indication of the battery charge condition Decisions on energy use can be made based on this check to avoid over discharge of the battery Such decisions may include delaying energy use or using backup generators to charge the batteries When you become more familiar with the operation of your system this battery check may occur less frequently For flooded batteries the battery bank also requires an equalisation charge to ensure that all individual cells in the bank are at a similar charge This is achieved by charging the battery until bubbling gassing occurs The period between equalisation charges is dependent upon manufacturer and typically vary from 7 28 d
15. inside the inverter 24 solar PV Systems Users maintenance guide Regulator s Each of the renevvable energy charging sources PV array wind generator and pico hydro generator will require their own specific charge regulator or controller Any regulator should be installed in a clean dry and ventilated area The regulator is an electronic device that controls the voltage of the charging sources solar wind hydro energy output to charge the battery bank appropriately The regulators are designed to disconnect or reduce the charge current when preset voltages are reached Typically there are boost voltage settings and float voltage settings Inspect and check the functioning of the regulator to ensure that any indicators or meters are correctly operating for the various regulator modes In the case of a PV system check that when the batteries are fully charged and it is sunny that the solar regulator is changing into float mode The wind generator and pico hydro regulator do operate differently to the solar regulator If you have a wind generator or pico hydro generator the regulators used are known as shunt regulators and will require additional components known as dummy loads typically a bank of resistive coils When the battery bank reaches the preset voltage the current from the generator source is shunted into the dummy load During maintenance checks inspect the fun
16. meter 26 Pico hydro meter 26 System voltage meter 27 Other monitoring 27 C Grid connected solar PV systems 28 1 PV solar modules 29 2 Inverters 30 3 Balance of system 30 4 How do I know my system is working 31 Annex 1 SPS maintenance log sheets 32 Solar array log sheet 32 Battery bank log sheet 34 Balance of systems log sheet 35 Genset log sheet 36 Wind generator log sheet 36 Pico hydro log sheet 37 Annex 2 GC maintenance log sheets 38 Solar array log sheet 38 Inverter log sheet 40 BOS log sheet 40 Annex 3 Glossary 41 Annex 4 SPS maintenance at a glance 43 Safety First 43 Annex 5 Information to be obtained from System Supplier or Manufacturers 44 A Introduction 3 A Introduction 1 About this guide This guide will give you an overview of the maintenance required for a typical stand alone solar power system SPS and grid connected solar power system GC including precautions and warnings on the hazards of working with solar power systems SPS maintenance is covered in Section B and GC in Section C For each section e the first three chapters provide an overview of each of the individual components followed by a more detailed description of the maintenance required e the final chapter describes how to monitor the operation of the system A definition of all words or phrases in bold italics is provided in Anne
17. should also be available to be used with water to neutralise any acid that is spilled onto the ground and the end 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 Sealed lead acid batteries The hazards related to a sealed lead acid battery include the risk of e explosion due to hydrogen gas if covered e shorting of terminals on and between the individual cells and e electrocution caused by having a nominal output voltage 120V DC or greater To minimise the hazards the following precautions should be taken when undertaking any maintenance e no smoking or naked flames e no maintenance should be undertaken if there is a strong smell of sulphuric acid in the vicinity of the battery bank and e the end 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 A Introduction 7 Solar modules Gensets The hazards related to solar modules include the risk of e electric shock due to array open circuit voltage greater than 120V d c and falling from the roof when performing maintenance DANGER NOTE If the solar modules are connected in an array where the open circuit voltage is 120V DC or above maintenance can only be undertaken by a suitably licensed electrical worker or contractor The
18. the battery warranty conditions Check with the system supplier concerning any logbook requirements 4 otar Pv systems Users maintenance guide 2 Precautions and warnings Solar power systems are safe when operating correctly however there are potentially dangerous hazards associated with some system components These hazards can include e 240V outputs and other dangerous voltages batteries solar modules gensets e wind generators and pico hydro generators Safety warnings The following symbols appear in this manual Immediate SAFETY Hazard DANGER Failure to follow recommended procedure will result in serious injury General SAFETY Warning AN Failure to follow recommended procedure could result in injury Electrical SAFETY Warning ZN Failure to follovv recommended procedure could result in injury Work Safely Wear protective eyewear and appropriate clothing during maintenance ri mie yes T A stand alone povver system SPS typically provides 240V AC power without being connected to the electricity grid i A grid connected power system GC provides 240V AC power by being connected to the electricity grid often referred to as power lines or mains power A Introduction 5 Although 240V AC power is dangerous and can cause death when live exposed wires terminals are touched or cause fire it i
19. wind generators or pico hydro generators this chapter does finish with a summary of the maintenance requirements for these two items B Stand alone solar PV systems 11 1 Energy generation equipment Energy generation equipment includes the solar photovoltaic array gensets wind generators pico hydro generators and is also considered to include associated equipment such as frames trackers towers water pipes and regulators or controllers The regulators and controllers are discussed in chapter B3 Solar array The solar array a number of solar modules mounted together is quite often referred to as being maintenance free This can be the case in many situations however with occasional maintenance and inspection the performance of all the solar modules in the array can be assured The most common maintenance task for solar modules is the cleaning of the glass area to remove excessive dirt An example of a PV panel maintenance log sheet is shown in Annex 2 In most situations cleaning is only necessary during long dry periods when there is no rain to provide natural cleaning To remove a layer of dust and dirt from the modules simply wash the module with water If the module has thick dirt or grime which is harder to remove wash with warm water and a sponge Washing the modules is similar to washing glass windows but detergents should not be used The modules should be cleaned when they
20. Solar PV systems Australian Business Council for Sustainable Energy Solar PV Systems Users maintenance guide Australian Government Australian Business Council for Sustainable Energy Produced by Australian Business Council for Sustainable Energy GO Leicester Street Carlton Victoria 3053 Australia Phone 03 9349 3077 Website www bcse org au Funded by Australian Greenhouse Office Major contributors Jeff Hoy JP Energy Technologies Brad Shone Alternative Technology Association ATA Geoff Stapleton Global Sustainable Energy Solutions Mike Russell Business Council for Sustainable Energy Nigel Wilmot Research Institute for Sustainable Energy RISE ISBN 978 0 9802806 9 2 Department of the Environment and Water Resources Australian Greenhouse Office The information in this guide has been provided as a guide to solar PV systems While every effort has been made to ensure the content is useful and relevant no responsibility for any purchasing decision based on this information is accepted by the Australian Business Council for Sustainable Energy or other contributors Australian Government funding through the Australian Greenhouse Office in the Department of the Environment and Water Resources supports this project The views expressed herein are not necessarily the views of the Commonwealth and the Commonwealth does not accept responsibility for any
21. ank must be protected by a suitable enclosure which is only accessible by appropriately authorised people eg system owner installer service person In large sheds the battery bank should still be housed in either a separate room or battery box to prevent unauthorised access and to separate spark sources B Stand alone solar PV systems 1 5 099 96 9 0 Safety first NO Always remember that a battery is a form of energy storage which under certain conditions can release its energy instantaneously with explosive consequences The battery bank should only be accessible to people who understand its functioning and are responsible for its maintenance It should be able to restrict access to other people especially children As far as possible the area should be animal and vermin proof Restricting access to the batteries will be the first and often the DANGER O of b afisey sapioalon NO best safety measure Suitable safety signs should caution people of the dangers see example signage above B N 5 5 FLAMES The following safety equipment should always be available and ready to use People who have access to the battery bank area should all be instructed in its use e Bucket of clean water for rinsing off acid splashes ur TE Safety goggles or face shield for face and eye prote
22. ase OK Pico hydro Working OK Log completed C Intake cleaned 8 Solar Pv systems Users maintenance guide Annex 5 Information to be obtained from stem supplier or manufacturers e What is the manufacturer s recommendation for a maximum depth of discharge of the batteries What is the recommended time between equalisation charges If using sealed batteries obtain chart showing battery voltage in relation to state of charge Obtain tables or graphs that relate specific gravity readings and temperature to state of charge information What is the maximum charging current Printed on recycled paper
23. asks Preparing the system for battery maintenance t is important to avoid clutter around the battery bank so remove all unnecessary items leaving only safety gear and equipment required for the maintenance of the battery bank ZN Before starting the battery bank maintenance it is extremely important to isolate the battery bank from the system to shut the system down Follovv the specified shutdown procedure you should see a sign on the wall near your equipment spelling out this procedure The user manual may provide further information Ensure there is plenty of ventilation in the battery enclosure or room If using forced ventilation check that ventilation systems are functioning correctly and are clean and unobstructed Before assessing the condition of a battery it is best to have a fully charged battery Isolating the system for maintenance A typical process in shutting down a system and isolating the battery bank to make it safe to perform the maintenance tasks would follow the following steps 1 Shut down turn off all loads on the system starting from the household appliances and working back to the inverter 2 Disconnect turn off all energy generation devices such as solar or wind generators 3 Shut down the battery bank this would involve either switching off circuit breakers or removing any fuses on the battery bank If fuses It is also best to wait for the solar
24. ays but some batteries can be as high as 90 days Please check with your system supplier If the equalisation charge is not achieved by the solar array then the genset will need to be run and the charging provided by the separate battery charger Checking the voltage The table below lists typical voltage levels that indicate whether the state of charge is good or bad for the battery bank This table is valid when the batteries are at rest ie no charge or discharge is occurring This table should only be used as a guide and for accurate charge levels the specific gravity of each cell should be tested where possible The table below is typical of flooded wet cell batteries at 25 C At higher or lower temperatures correction should be made using temperature correction factors from your battery specifications If you have gel cell batteries you can only check the battery specifications from the manufacturer for an indication of state of charge for various voltage levels Nominal Bad Time to start Good Caution Voltage economising or using depending backup charger on battery see note 2V lt 1 9 1 9 2 0 2 2 2 gt 2 4 12V lt 11 4 11 4 12 12 13 2 gt 14 4 24V lt 22 8 22 8 24 24 26 4 gt 28 8 48V lt 45 6 45 6 48 48 52 8 gt 57 6 Note Some batteries have an equalisation or boost charge of 2 6V per 2V cell 18 solar Pv Systems Users maintenance guide Typical battery maintenance t
25. bolts rusting and checks to ensure that the frame and modules are firmly secured An example of a PV panel maintenance log sheet is shown in Annex 2 30 Solar PV Systems Users maintenance guide 2 Inverters These items generally e keep the inverter clean e check that the inverter is require very little and minimise the functioning correctly by maintenance but when possibility of dust being observing LED indicators maintenance is being blown over the equipment metering and or other performed on other parts of clean with dry cloth displays on the inverter the system then the when required An example of an inverter log sheet is shown in following should be ensure the unit is not undertaken infested by vermin and Annex 2 3 Balance of system These items generally Typically grid connected PV An example of a BOS log require very little systems are using plug sheet is shown in Annex 2 maintenance but when cables between the solar maintenance is being modules in the array and performed on other parts of when mounted on the roof the system then the these are often hidden following should be behind the solar modules undertaken Therefore the only cables e check that all that can be inspected will be interconnections and the cables and or conduits cables conduits are e from the array to the mechanically secure inverter and e check that all switches e the inverter to the and circuit breakers are
26. ction Rubber gloves for protection of hands Eyevvash bottle for rinsing acid splashes out of eyes Overalls or apron for protection of body and clothing from acid splash Baking soda Bicarbonate for neutralising acid spills from explosive vented battery gases All battery installations should be either naturally or forced ventilated to prevent the build up of explosive gases The battery enclosure should be clean dry and lockable to prevent unauthorised access It should also house only the batteries Good access to the battery terminals and electrolyte filler caps is required Generally batteries are installed on a battery rack or on timber to keep them off the floor and provide the required access to the batteries There should not be shelves or any other equipment above the batteries because items falling from these shelves onto the batteries could cause a Short circuit or the equipment itself could be spark generating In addition gases from the battery can corrode equipment Avoid clutter around the battery enclosure to facilitate easy access The battery enclosure must not be used as a storage area Minimise the battery bank s exposure to extremes of temperature because this can reduce performance and life The battery bank should be installed so that each individual battery is exposed to the same temperature conditions Provision should be made for the containment of any
27. ctioning of the regulator to ensure that any indicators or meters are correctly operating for the various regulator modes In general correct operation of the regulator s can only be observed in certain conditions This is achieved by observing that the charge currents from the different sources solar wind or pico hydro are either removed or reduced when specified voltages are obtained This could be observed when the voltage of the battery reaches a certain point this indicates that the battery is fully charged and the regulators go from boost to float mode Full operation tests might need to be undertaken by a suitably qualified person eg the system supplier installer When inspecting the regulators e look for any loose wiring on the terminal connections If they are loose follow the shutdown procedures for the system before tightening the connections or contact your installer remove any excess dust from the unit and especially from the heat sinks This should only be done with a dry cloth or brush Switchboards and wiring Correctly installed switch boards and wiring should not require maintenance visually inspected for signs of corrosion and or burning If either is apparent consult a licensed electrical contractor to identify and rectify possible faults The licensed electrical contractor who installed the system should have checked all existing wiring and switchboards
28. d batteries The state of charge of the battery can only be determined by measuring voltage of the battery when there has been no discharging or charging of the battery for at least 15 30 minutes and referring to tables supplied by the manufacturer B Stand alone solar PV systems 23 3 Balance of systems BOS Balance of systems include e regulators or controllers for the solar array wind generator and pico hydro generator e inverters e all interconnecting power cables and control cables between the individual components to create the system The inverter The inverter should be installed in a clean dry and ventilated area which is sep arated from and not directly above the battery bank While the system is operat ing the following operational checks can be made e check that the inverter is functioning correctly by observing LED indicators metering and or other dis plays on the inverter e check to see if the inverter s stand by mode if present is functioning correctly This can be done by turning off all loads and appliances operating on the system Once in stand by mode switch an appliance on and the inverter should start almost immediately check that any control functions for remote starting of diesel genset if installed are operating Ensure that the diesel e all switchboards protection equipment and metering monitoring equipment This equipment re
29. e holding the wind turbine trackers follows the path of the sun vented open to the air wind generators converts wind energy into electrical energy Annex 4 SPS maintenance at a glance 43 Annex 4 SPS maintenance at a glance Safety first DATE 1 Do not climb above 2 metres to maintain PV modules or wind turbines without safety rails or harness 2 Do not touch any component with a voltage 120V DC 50V AC or greater 3 Wear personal protective clothing when maintaining batteries 4 Do not maintain batteries while there s an acrid smell in the vicinity 5 No smoking sparks or naked flames in battery enclosure 6 Ensure clean water is readily accessible while maintaining batteries 7 Ensure all tools are insulated while maintaining batteries PV Modules Balance of System Battery Genset Cleaned Battery voltage Battery voltage Run hours Check structure Switches CBs Interconnections Oil change Cabling mechanical Connections Ambient temp C Fuel filter Cabling electrical Regulator Log completed Oil filter Output voltage Inverter Air filter Output current Charger SG Log completed Log completed Control board Temperature Ci aned SoC Wind Generator Bugs removed Voltage LI Guys Cables Water R C
30. em regulators refer to the system supplier for advice if you suspect either of these problems B Stand alone solar PV systems 27 System voltage meter If a system has metering for the system DC voltage battery voltage by observing the voltage regularly at a similar time of day any loss of performance might be noticed The system voltage will be higher when being charged and lower when there is no charge and there are loads present A good time to observe the voltage is first thing in the morning and at night time If the voltage is lower than expected then this could indicate that e the system is not being charged effectively or e the energy usage has increased thereby using more than the system is producing or e battery cells are getting old and either losing efficiency or a cell might have failed If you are unable to determine the problem contact your system supplier for advice Other monitoring Many of the inverters and regulators on the market today are microprocessor controlled and therefore allow other monitoring features This can include the ability to data log your system for a period of time and even allow for remote monitoring via modems and phone lines These will typically include all the meters mentioned above but will often include measuring the amount of energy being produced and consumed daily If your system includes this type of monitoring logging the daily energy fl
31. ger to battery bank e inverter and genset to AC switchboard An example of poorly wired unprotected and unsupported cabling for a charger 26 Solar PV Systems Users maintenance guide 4 Often a system owner is unaware of a problem until suddenly the inverter turns off and the house has no power Typically the system will include a back up genset so that this can be operated to provide power to the house but this will be noisy expensive environmentally unfriendly and inconvenient As a minimum the Australian Standard recommends that your system should include a volt meter for measuring the system DC voltage and a current meter from each of the charging sources solar wind and or pico hydro Regularly monitoring these meters will help to identify a problem before the point is reached where the inverter switches off due to low battery state of charge reflected by low battery voltage Interpretation of monitoring equipment Solar array meter If a system has metering the solar array output by observing the output current regularly any loss of perform ance may be noticed There will be some variation in this current due to changes in ambient temperature sea son of the year angle of the sun and the level of solar radiation incident on the modules To minimise these effects this observation should be done on fine cloud free days at around noon Any significant changes in outpu
32. he battery terminal posts and the battery lead connectors Battery terminal corrosion is often seen as a white crystalline or powdery material around or on the battery terminals A heavily oxidised terminal will have a very dark almost black coating If this is between mating surfaces of the connectors and posts it will need to be cleaned Before disconnecting carefully wipe most of the corrosion off using a brush or rag with the baking soda solution then carefully disconnect the battery lead connector from the battery terminal post and clean both using a plastic scourer Once clean apply the anti oxidising coating following the manufacturer s recommended procedure and reconnect the battery lead connector onto the battery terminal post Repeat this procedure for each terminal as required being careful not to contaminate the electrolyte with any foreign material Differences for gel cell type batteries Gel cell batteries require special attention to the method used for charging as overcharging of a gel cell type battery may cause irreversible damage to the battery Consult with system supplier for recommendations on charging of gel cell type batteries Controllers and chargers should be set to the gel cell mode for best performance Maintenance of gel cell batteries only relates to the battery terminals and connections The maintenance required for these is the same as for wet cell floode
33. id connected solar PV systems 29 1 PV solar modules The solar array a number of solar modules mounted alongside each other is often thought to be maintenance free This can be the case in many situations hovvever vvith occasional maintenance and inspection the performance of all the solar modules in the array can be assured The most common maintenance task for solar modules is the cleaning of the glass area of the module to remove excessive dirt n most situations cleaning s only necessary during long dry periods when there is no rain to provide natural cleaning To remove a layer of dust and dirt from the modules simply wash the panel with water If the module has thick dirt or grime which is harder to remove wash with warm water and a sponge Washing the modules is similar to washing glass windows but detergents should not be used After the modules have been cleaned a visual inspection of the modules can be done to check for defects in the modules such as cracks chips and discolouration If any obvious defects are found note their location in the system logbook so they can be monitored in the future in case further deterioration affects the modules output In most cases the module output will not be affected When inspecting the solar modules the condition of the array mounting frame if used should also be noted Items to observe should include the array mounting bolts eg
34. information or advice contained herein Solar PV Systems Users maintenance guide 1 Contents A Introduction 3 B Stand alone solar PV systems 10 1 About this guide 3 1 Energy generation equipment 11 Maintenance 3 Solar array 11 2 Precautions and warnings 4 Gensets 12 240 volt output 4 Wind generators 12 Battery banks 5 Pico hydro generators 12 Wet lead acid batteries 5 2 Battery bank 14 Sealed lead acid batteries 6 General installation requirements 14 Solar modules 7 Safety first 15 Gensets Maintenance of battery banks 16 VVind generators 8 Checking your batteries 16 Pico hydro generators 8 Charging your batteries 17 3 Maintenance schedules and logbooks 9 Checking the voltage 17 Typical battery maintenance tasks 18 Isolating the system for maintenance 18 Cleaning the cells 19 Checking the charge and condition of the battery bank 19 Voltage measurement 20 Specific gravity measurement 20 Using a hydrometer 20 Neutralising acid spills 21 Topping up the electrolyte 21 Cleaning the battery terminals 22 Differences for gel cell type batteries 22 3 Balance of Systems BOS 23 The inverter 23 Regulator s 24 Switchboards and wiring 25 Battery chargers 25 System wiring 25 4 Interpretation of monitoring equipment 26 Solar array meter 26 Wind generator
35. nating current ambient surrounding array A number of PV modules electrically interconnected balance of systems includes regulators inverters cables control board and protection equipment bi carbonate soda baking soda sodium bicarbonate boost charge A charging cycle that ensures the battery reaches close to fully charged also known as topping up the battery BOS Balance of System brake prevents the turbine from turning cable twist A mechanism in a wind turbine where the cables in the tower of the wind turbine can twist one way then another working on the theory that the wind turbine will approximately turn equally clockwise and anticlockwise so that the cable does not twist too tight cells a single battery unit usually 2 volts circuit breakers an electrical protection device that automatically switches to off when overloaded DC direct current deep cycling suitable for large charge and discharge cycles depth of discharge percentage discharge of a battery dump loads a load to prevent the current from overcharging the battery electrolyte solution ina battery that stores energy and allows the current to pass energy generation devices PVs wind turbine genset or pico hydro generator equalisation overcharging to ensure all cells have equalised specific gravity and therefore each cell is fully charged exhaust gases contain noxious fumes exhaust sparks sparks in fumes which can cau
36. ow in and out will help determine whether your system is operating correctly and will often alert you to a problem before it causes a system failure In particular monitoring the energy generated each day provides more information than simply observing the charge current If this figure reduces substantially it will indicate there is a problem in the charging of the system By observing the amount of energy used each day you will then know if your energy consumption has increased By comparing the amount of energy generated with the amount of energy consumed you will then see whether you are e under using the system that is the system is producing more energy than you are using Note due to system losses you should always produce more than you use e using more than the system is producing and therefore you may soon have flat batteries and a system failure Alternatively you may need to run the genset and battery charger to compensate Your system supplier should train you to make effective use of the monitoring equipment 28 solar PV Systems Users maintenance guide The typical GC system will include PV modules inverter and BOS equipment including meters switching equipment and system wiring These sections provide an overview of the maintenance requirements for these pieces of equipment In particularly how do you know that your GC system is working C Gr
37. owner of the system MUST NOT undertake any maintenance to these solar modules other than simple cleaning To minimise the hazards the following precautions should be taken when undertaking any maintenance e when working on roofs there is always the risk of falling NEVER climb onto a roof to perform any service on the solar modules eg clean them unless there is a barrier eg scaffolding to prevent you from falling or you are wearing an approved safety harness which is supported correctly The hazards related to gensets include the risk of electrocution due to 240V AC output and ignition of flammable and or explosive fuels inhaling of exhaust gases combustion caused by exhaust sparks burns from hot exhaust pipe the presence of a battery See above accidents from moving parts ear damage due to noise They also have rotating parts and these should be protected during operation To minimise the hazards the following precautions should be taken when undertaking any maintenance follow all recommendations provided in the equipment manuals or use a qualified service technician DANGER Any service required to the LV wiring must be undertaken by a suitably licensed electrical worker or contractor Wind generators Pico hydro generators The hazards related to wind generators can include the risk of e electrocution due to dangerous voltages either DC or AC LV e falling from the top of
38. peat this three to four times to ensure that the hydrometer is at the same temperature as the Now fill the hydrometer and hold it vertically ensuring its float is floating in the electrolyte Now read the electrolyte level off the float Return the electrolyte to the cell Record the reading in the logbook Rinse the hydrometer in fresh water and test the next cell following the same procedure until all cells are tested Topping up the electrolyte When batteries are charging and gassing the battery is losing water To top up the electrolyte use distilled water or de ionised water and fill the battery via the electrolyte filler hole until the correct level is reached There are several types of indicators to show the level is correct These indicators vary from simple markings on the side of the battery case indicating high and low levels to systems which use a float indicator Check the manufacturer s instructions for the type of indicator used in your batteries It is preferable to add distilled water when the battery charge is high as the addition of water will decrease the charge of the battery 22 solar PV Systems Users maintenance guide Cleaning the battery terminals If the battery terminals are showing signs of corrosion or have not had an anti oxidising coating applied they may require cleaning This will involve disconnecting the battery leads and cleaning both t
39. quires little maintenance If this equipment requires any maintenance or repair it will generally need to be done by qualified personnel and the genset is starting and stopping at correct battery voltage levels as specified by manufacturer refer to system supplier or inverter operating manual NOTE The third check can be difficult to undertake as it can require disconnecting all charging sources eg PV array and turning on sufficient appliances to force the battery voltage to decrease to the set voltage for starting the genset It could also be simulated by raising the voltage setting so checking that the generator does start at the higher voltage which is close to the actual voltage of the battery bank The exact testing method will depend on the actual set up of the system and probably might only be able to be undertaken by a suitably qualified person eg the system supplier installer supplier should be contacted for advice Typically the system owner is only aware that the genset has not started when the batteries have reached a low voltage When inspecting the inverter remove any excess dust from the unit and especially from the heat sinks This should only be done with a dry cloth or brush Check that vermin have not infested the inverter eg typical signs of this include spider webs on ventilation grills or wasps nests in heat sinks Contact system suppliers if you suspect vermin are
40. regulator wind generator dump load or pico hydro dump load to have finished a boost charge before switching to a float charge mode For consistency in the recording of specific gravity and voltage measurements each cell should have a permanent number identification on it which is not easily erased by wear and maintenance When recording specific gravity or voltage these numbers can be used as a reference label are used the fuse on the negative terminal of the battery bank should be removed first followed by the fuse on the positive terminal 4 If a switch fuse is used opening the svvitch fuse disconnects the fuses from the batteries Remove the front mechanism to prevent it being closed vvhile you are vvorking 5 VVhen a circuit breaker is used either place a Do Cleaning the cells Each cell should be clean before removing any filler caps to perform maintenance or measurements This vill avoid contamination of the cell by dirt To clean the cells use either a brush to remove dry material and or a rag dipped in a solution of baking soda and water and thoroughly squeezed out not operate tag on the circuit breaker or physically isolate the battery bank by removing the battery cabling first from the negative 6 Z N 6 VVARNING VVhen cleaning batteries avoid using excess water which may spill into the cell and always wipe away from electrolyte filler holes Do not allow any
41. s B and C A loose leaf folder can be used as the system log book with individual sheets added for each item Though having one folder might be ideal for an SPS often you will have a couple of logbooks due to gensets requiring regular services like a car and can be supplied with their own logbook Battery bank manufacturers can often supply battery logbooks which must be completed to meet warranty conditions If you do have separate logbooks it is advisable to keep them together in a clean dry location Annex 1 SPS and Annex 2 GC provide examples of sheets that can be used for each piece of equipment When completing the log sheets the date and name of person undertaking the maintenance or inspection should be recorded Log books can be particularly useful because the historical information they contain can show changes over time as well as abnormal variations from the usual indicating a problem or a potential problem 10 solar Systems Users maintenance guide Prior to performing any maintenance follow shut down procedures as specified in your system manual The typical SPS will include e PV array of modules battery bank e balance of system BOS equipment including inverter regulator s battery charger system wiring and e a genset These sections cover the maintenance requirements for these components which includes the complete system integrity Since some systems include
42. s generally safe when kept in good working order Low voltage LV is specified in the Australian Standards as any voltage equal to or higher than 50V AC or 120V DC Any service requiring LV wiring must be undertaken by a Suitably licensed electrical worker or contractor The owner of the system MUST NOT undertake any maintenance to LV wiring systems or the output terminals of equipment that produces low voltage LV Battery banks Wet lead acid batteries The hazards related to a wet lead acid battery bank include the risk of e explosion due to hydrogen gas e burns caused by acid in the individual cells The owner of the system MUST NOT undertake any maintenance to battery banks 120V DC or above The battery bank can include either wet lead acid or sealed lead acid cells shorting of terminals on and between the individual cells and electrocution caused by an output voltage 120V DC or greater To minimise the hazards the following precautions should be taken when undertaking any maintenance e no maintenance should be undertaken if there is a strong smell of sulphuric acid in the vicinity of the battery bank e no smoking or naked flames safety goggles MUST be worn acid resistant gloves MUST be worn acid resistant apron or clothing should also be worn clean water should be available near the batteries to wash any acid that comes in contact with skin bi carbonate soda
43. se fire float sealed cylinder inside hydrometer float charge intermittent charging of the battery at a voltage specified by manufacturer also known as intermittent topping up of the battery flooded A battery with wet electrolyte within the battery case and around the electrodes forced ventilated powered by a fan fuels usually diesel LPG or petrol furling turning the blades to avoid the wind fuses protection devices that break the overload by burning a wire inside their casing must be replaced when operated GC connected to the mains power grid gel the electrolyte in the battery is a gel as distinct to a liquid solution gensets a diesel LPG or petrol 240V generator guy wires supports holding tower of wind tower in place heat sinks finned steel to help dissipate heat hot exhaust pipe from a fuel genset and can cause burns hot joints poor electrical contact causing heating hydrogen a volatile gas given off during charging of batteries hydrometer device for measuring specific gravity incident striking insulated prevents electrical shorting integrity components working correctly and in harmony inverter converts DC current into 240 V AC isolate cut off electrically lead acid the electrolytic compound and the electrodes LED light emitting diode 42 solar PV Systems Users maintenance guide live carrying an electrical current loads appliances drawing electricity logbook book recording
44. spilled electrolyte Maintenance of battery banks Generally maintenance of batteries will concentrate on correct charging regimes electrolyte condition battery terminals and overall battery safety Before you start Before you start with your maintenance ensure all safety equipment is at hand and ready to use Listed below is typical equipment you will need for these maintenance tasks safely and correctly Safety equipment See safety first above Hydrometer for checking specific gravity of electrolyte and hence battery charge e Glass bulb type thermometer for temperature measurement of electrolyte Container with clean water Plastic type dishwashing to rinse hydrometer and scourer or similar for thermometer cleaning battery terminals Handheld voltmeter or and connectors multimeter for checking e Anti oxidant coating for battery voltage coating battery terminals e Appropriate tools correct and connectors after size spanners and or cleaning screwdrivers with Baking soda for cleaning insulated handles of batteries Checking your batteries As part of regular maintenance a thorough visual inspection of the battery bank is required This inspection should include e cleanliness of batteries e level of electrolyte not required for gel cell batteries e condition of battery terminals e signs of any electrolyte in the safety trays
45. switchboard operating correctly and e confirm any meters are operating correctly C Grid connected solar PV systems 31 4 Hovv do 1 knovv my system is vvorking VVith a grid connected PV system there are no moving parts During the day when the sun is shining on the modules they are quietly producing electricity which is either being consumed in your house or exported to the grid Since it s so quiet how do you know it s working It is recommended that as a minimum your system should include a meter that records either the amount of energy being generated by the modules or the amount being exported to the grid If it is only measuring the production then you could record the meter reading in the morning and then again that evening The difference in the reading will determine the day s production If it is only measuring what is being supplied to the grid and you are consuming all your generated power then this meter will not move very often In this case turn off all appliances in the house and then observe whether that meter is moving Power output display Some systems will include meters that indicate exactly what is being produced at any time while other inverters will constantly monitor and record the energy generated It is important that your system supplier explains to you how to know if your system is working 32 Solar PV Systems Users maintenance guide Anne
46. t that are noticed can be investigated The most common causes for loss of output would be excessive dirt on the modules or partial shading of the array Other causes could include wiring problems and or problems with system regulators refer to the system supplier for advice if you suspect either of these problems Wind generator meter If a system has metering for the wind generator output by observing the output current regularly any loss of perform ance may be noticed The current will be dependent on the amount of wind but through regular observation on windy days you will notice that the generator is produc ing suitable current Any sig nificant changes in output which are noticed can be investigated Causes could include wiring problems and or problems with system regulators refer to the sys tem supplier for advice if you suspect either of these prob lems Pico hydro meter If a system has metering for the pico hydro output by observing the output current regularly any loss of per formance may be noticed Typically the output of a pico hydro generator is constant Any significant changes in output which are noticed can be investigated The most common causes for loss of output would be blockage of the inlet pipe thereby reduc ing the water flow or the water flow has reduced in the stream Other causes could include blocked jets in the turbine or wiring prob lems and or problems with syst
47. x 1 SPS maintenance log sheets The following log sheets components and the undertaken by a trained specify all the maintenance system Those maintenance service person They have that should be performed on items that are shaded in been included to ensure the each of the system grey are only to be log sheets are complete Solar array log sheet Date Name Cleaned Array Array Array Array Array modules structure cabling cabling output output OK mechanical electrical voltage current 9 Time VVeather Comments 34 9 9
48. x 3 the glossary Annexes 1 and 2 demonstrate sample log sheets for a system logbook Annex 3 is the glossary of terms introduced in this guide Annex 4 is an at a glance sheet Annex 5 is information to check with system supplier or manufacturer Maintenance As with any piece of equipment performing regular maintenance and inspection of components will help ensure system performance and minimise disruption due to component failure If our described procedures differ from those suggested by your manufacturer and or installer follow the procedures outlined in the system user manual supplied with your system This guide is designed for those already familiar with the basic components and configuration of solar power systems More introductory information can be found in the Electricity From The Sun Solar PV Systems Explained ISBN 978 0 9802806 7 8 available from your installer There are many books available to provide further details about these systems and components As part of the regular maintenance of a system it is recommended that you keep a logbook recording all system maintenance and performance In the logbook the type and frequency of maintenance and who performed it should be recorded If kept up to date it can be used to provide a history of the system which can then be used for fault diagnosis With some stand alone systems a logbook is required to be kept in accordance with
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