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Solar PV systems

Users’ maintenance guide

Produced byAustralian Business Councilfor Sustainable Energy60 Leicester StreetCarlton Victoria 3053AustraliaPhone: 03 9349 3077 Website: www.bcse.org.au

Funded byAustralian GreenhouseOffice

Major contributorsJeff Hoy, JP Energy

TechnologiesBrad Shone, Alternative

Technology Association(ATA)

Geoff Stapleton, GlobalSustainable EnergySolutions

Mike Russell, BusinessCouncil for SustainableEnergy

Nigel Wilmot, ResearchInstitute for SustainableEnergy (RISE)

ISBN: 978-0-9802806-9-2

The information in this guidehas been provided as aguide to solar PV systems.

While every effort has beenmade to ensure the contentis useful and relevant, noresponsibility for anypurchasing decision basedon this information isaccepted by the AustralianBusiness Council forSustainable Energy or othercontributors.

Australian Governmentfunding through theAustralian GreenhouseOffice in the Department ofthe Environment and WaterResources supports thisproject.

The views expressed hereinare not necessarily theviews of the Commonwealth,and the Commonwealthdoes not acceptresponsibility for anyinformation or advicecontained herein.

Solar PV Systems: Users maintenance guide

Solar PV Systems: Users maintenance guide 1

B: Stand-alone solar PV systems 10

1. Energy generation equipment 11Solar array 11

Gensets 12

Wind generators 12

Pico-hydro generators 12

2. Battery bank 14General installation requirements 14

Safety first! 15

Maintenance of battery banks 16

Checking your batteries 16

Charging your batteries 17

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

A: Introduction 3

1. About this guide 3Maintenance 3

2. Precautions and warnings 4240 volt output 4

Battery banks 5

Wet lead-acid batteries 5

Sealed lead acid batteries 6

Solar modules 7

Gensets 7

Wind generators 8

Pico-hydro generators 8

3. Maintenance schedules and logbooks 9

Contents

2 Solar PV Systems: Users maintenance guide

3. Balance of Systems (BOS) 23The inverter 23

Regulator(s) 24

Switchboards and wiring 25

Battery chargers 25

System wiring 25

4. Interpretation of monitoring equipment 26Solar array meter 26

Wind generator meter 26

Pico-hydro meter 26

System voltage meter 27

Other monitoring 27

C: Grid-connected solarPV systems 28

1. PV solar modules 292. Inverters 303. Balance of system 304. How do I know my system is working? 31

Annex 1: SPS maintenancelog 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 maintenancelog sheets 38

Solar array log sheet 38

Inverter log sheet 40

BOS log sheet 40

Annex 3: Glossary 41

Annex 4: SPS maintenanceat a glance 43

Safety First 43

Annex 5: Information to beobtained from SystemSupplier or Manufacturers 44

A: Introduction 3

SPS maintenance is coveredin Section B and GC inSection C.

For each section:• the first three chapters

provide an overview ofeach of the individualcomponents followed by amore detailed descriptionof the maintenancerequired;

• the final chapter describeshow to monitor theoperation of the system.

* A definition of all words orphrases in bboolldd iittaalliiccss isprovided in Annex 3, theglossary

Annexes 1 and 2demonstrate sample logsheets for a systemllooggbbooookk.

Annex 3 is the glossary ofterms introduced in thisguide.

Annex 4 is an at-a-glancesheet.

Annex 5 is information tocheck with system supplieror manufacturer

Maintenance

As with any piece ofequipment, performingregular maintenance andinspection of componentswill help ensure systemperformance and minimisedisruption due to componentfailure. If our describedprocedures differ from thosesuggested by yourmanufacturer and/orinstaller, follow theprocedures outlined in thesystem user manualsupplied with your system.

This guide will give you an overview of themaintenance required for a typical stand-alonesolar power system (SSPPSS)* and grid-connectedsolar power system (GGCC) including precautionsand warnings on the hazards of working withsolar power systems.

This guide is designed forthose already familiar withthe basic components andconfiguration of solar powersystems. More introductoryinformation can be found inthe Electricity From The Sun– Solar PV SystemsExplained (ISBN: 978-0-9802806-7-8) available fromyour installer. There aremany books available toprovide further details aboutthese systems andcomponents.

As part of the regularmaintenance of a system, itis recommended that youkeep a logbook recording allsystem maintenance andperformance. In the logbookthe type and frequency ofmaintenance and whoperformed it should berecorded. If kept up to date,it can be used to provide ahistory of the system whichcan then be used for faultdiagnosis. With some stand-alone systems, a logbook isrequired to be kept inaccordance with the batterywarranty conditions. Checkwith the system supplierconcerning any logbookrequirements.

A: Introduction

1. About this guide


2. Precautions and warnings

Solar power systemsare safe whenoperating correctlyhowever there arepotentially dangeroushazards associatedwith some systemcomponents.

These hazards can include:• 224400VV outputs and other

dangerous voltages;• batteries;• solar mmoodduulleess;• ggeennsseettss; • wwiinndd ggeenneerraattoorrss; and• ppiiccoo--hhyyddrroo ggeenneerraattoorrss.

Safety warnings

The following symbolsappear in this manual.

Immediate SAFETYHazard

Failure to followrecommendedprocedure will result inserious injury.

General SAFETYWarning

Failure to followrecommendedprocedure could resultin injury.

Electrical SAFETYWarning

Failure to followrecommendedprocedure could resultin injury.

Work Safely

Wear protective eyewearand appropriate clothingduring maintenance.

A stand-alone power system(SSPPSS) typically provides240V AC power withoutbeing connected to theelectricity grid.

A grid-connected powersystem (GC) provides 240VAC power by beingconnected to the electricitygrid, often referred to aspower lines or mains power.

240 volt output

A: Introduction 5

Battery banks

NOTE If the battery bankhas a nominal voltage of120V DC or above,maintenance can only beundertaken by a suitablylicensed electricalworker or contractor.

The owner of the systemMUST NOT undertake anymaintenance to batterybanks 120V DC or above.

The battery bank can includeeither wweett lleeaadd--aacciidd orsealed lead-acid cells.

Although 240V AC power isdangerous and can causedeath when live exposedwires/terminals are touchedor cause fire, it is generallysafe when kept in goodworking order.

Low voltage (LV) is specifiedin the Australian Standardsas any voltage equal to orhigher than 50V AC or 120VDC. Any service requiring LVwiring must be undertakenby a suitably licensedelectrical worker orcontractor. The owner of thesystem MUST NOTundertake any maintenanceto LV wiring systems or theoutput terminals ofequipment that produces lowvoltage (LV).

Wet lead-acid batteries

The hazards related to a wetlead-acid battery bankinclude the risk of:• explosion due to hhyyddrrooggeenn

gas;• burns caused by acid in

the individual cells;

• sshhoorrttiinngg of tteerrmmiinnaallss onand between the individualcceellllss; and

• electrocution caused by anoutput voltage 120V DC orgreater.

To minimise the hazards thefollowing precautions shouldbe taken when undertakingany maintenance:• no maintenance should be

undertaken if there is astrong smell of sulphuricacid in the vicinity of thebattery bank;

• no smoking or nakedflames;

• safety goggles MUST beworn;

• acid resistant glovesMUST be worn;

• acid resistant apron orclothing should also beworn;

• clean water should beavailable near thebatteries to wash any acidthat comes in contact withskin;

• bbii--ccaarrbboonnaattee ssooddaa shouldalso be available to beused, with water, toneutralise any acid that isspilled onto the ground;and

• the end of spanners (orany other tools) that youwill use near the batterybank should be iinnssuullaatteeddto avoid any accidentalshorts between theterminals.


The hazards related to a sealed lead acidbattery include the risk of:• explosion due to hydrogen gas (if

covered);• shorting of terminals on and between the

individual cells; and• electrocution caused by having a nominal

output voltage 120V DC or greater.

To minimise the hazards, the followingprecautions should be taken whenundertaking any maintenance:• no smoking or naked flames• no maintenance should be undertaken if

there is a strong smell of sulphuric acid inthe vicinity of the battery bank; and

• the end of spanners (or any other tools)that you will use near the battery bankshould be insulated to avoid anyaccidental shorts between the terminals.

Sealed lead acid batteries

A: Introduction 7

Solar modules

The hazards related to solar modulesinclude the risk of:• electric shock due to aarrrraayy ooppeenn--cciirrccuuiitt

voltage greater than 120V d.c; and• falling from the roof when performing

maintenance.

NOTE If the solar modules are connectedin an array where the open circuitvoltage is 120V DC or above,maintenance can only be undertaken bya suitably licensed electrical worker orcontractor.

The owner of the system MUST NOTundertake any maintenance to these solarmodules other than simple cleaning.

To minimise the hazards the followingprecautions should be taken whenundertaking any maintenance:• when working on roofs there is always the

risk of falling. NEVER climb onto a roof toperform any service on the solar modules(eg. clean them) unless there is a barrier(eg. scaffolding) to prevent you from fallingor you are wearing an approved safetyharness which is supported correctly.

Gensets

The hazards related to gensets include therisk of:• electrocution due to 240V AC output; and• ignition of flammable and/or explosive

ffuueellss• inhaling of eexxhhaauusstt ggaasseess• 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 nnooiissee.

They also have rotating parts and theseshould be protected during operation.

To minimise the hazards the followingprecautions should be taken whenundertaking any maintenance:• follow all recommendations provided in

the equipment manuals; or• use a qualified service technician.

Any service required to the LV wiringmust be undertaken by a suitablylicensed electrical worker or contractor.


Wind generators

The hazards related to wind generators caninclude the risk of:• electrocution due to dangerous voltages

(either DC or AC LV) ;• falling from the top of a pole or structure;• damage caused by rotating and/or moving

parts.• an accident while lowering or raising of

ttoowweerr• damage by stumbling into unfenced or

unprotected gguuyy wwiirreess• being hit by tail in sudden wind gusts (if

structure tower is suitable for climbing).

To minimise the hazards the followingprecautions should be taken whenundertaking any maintenance:• follow all recommendations provided in

the equipment manuals; and• use a brake on turbine before lowering or

raising tower; or• use a qualified service technician.

Pico-hydro generators

The hazards related to pico-hydro generatorscan include the risk of:• electrocution due to dangerous voltages

(either DC or AC LV) ;• falling whilst accessing pipes in steep and

slippery locations; and• accidents caused by rotating and/or

moving parts.

To minimise the hazards, the followingprecautions should be taken whenundertaking any maintenance:• follow all recommendations provided in

the equipment manuals; and• turn off water source or• use a qualified service technician.

Any service required to the LV wiringmust be undertaken by a suitablylicensed electrical worker or contractor.

A: Introduction 9

Suggested maintenance intervals andrecords for major equipment components ofan SPS or GC system are provided insections B and C.

A loose-leaf folder can be used as thesystem log book with individual sheetsadded for each item.

Though having one folder might be ideal foran SPS, often you will have a couple oflogbooks due to gensets requiring regularservices like a car and can be supplied withtheir own logbook. Battery bankmanufacturers can often supply batterylogbooks, which must be completed to meetwarranty conditions.

If you do have separate logbooks, it isadvisable to keep them together in a cleandry location.

Annex 1 (SPS) and Annex 2 (GC) provideexamples of sheets that can be used foreach piece of equipment. When completingthe log sheets, the date and name ofperson undertaking the maintenance orinspection should be recorded.

Log books can be particularly usefulbecause the historical information theycontain can show changes over time, aswell as abnormal variations from the usual,indicating a problem, or a potential problem.

A maintenance schedule with anequipment logbook (or logbooks)should be provided as part of thedocumentation supplied to thesystem owner by the supplier at thecompletion of system installationand commissioning.

3. Maintenance schedules and logbooks


B: Stand-alone solar PV systems

Prior to performing anymaintenance, follow shut downprocedures as specified in yoursystem manual.

The typical SPS will include:• PV array of modules;• battery bank;• balance of system (BOS)

equipment—including inverter,regulator(s), battery charger,system wiring; and

• a genset.

These sections cover themaintenance requirements forthese components whichincludes the complete systemiinntteeggrriittyy.

Since some systems includewind generators or pico-hydrogenerators, this chapter doesfinish with a summary of themaintenance requirements forthese two items.


The solar array (a number ofsolar modules mountedtogether) is quite oftenreferred to as beingmaintenance free. This canbe the case in manysituations, however, withoccasional maintenance andinspection, the performanceof all the solar modules inthe array can be assured.

The most commonmaintenance task for solarmodules is the cleaning ofthe glass area to removeexcessive dirt.

An example of a PV panelmaintenance log sheet isshown in Annex 2.

Energy generation equipment includes the solar pphhoottoovvoollttaaiicc array,gensets, wind generators, pico-hydro generators and is also considered toinclude associated equipment such as frames, ttrraacckkeerrss, towers, waterpipes and rreegguullaattoorrss or controllers. The regulators and controllers arediscussed in chapter B3.

In most situations cleaningis only necessary duringlong dry periods when thereis no rain to provide naturalcleaning. To remove a layerof dust and dirt from themodules, simply wash themodule with water. If themodule has thick dirt orgrime, which is harder toremove, wash with warmwater and a sponge.Washing the modules issimilar to washing glasswindows but detergentsshould not be used. Themodules should be cleanedwhen they are notexcessively hot, typicallyearly in the morning.

After the modules have beencleaned, a visual inspectionof the modules can be doneto check for defects such ascracks, chips anddiscolouration. If any obviousdefects are found, note theirlocation in the systemlogbook, so these can bemonitored in the future incase further deteriorationaffects the modules’ output.

When inspecting the solarmodules, the condition ofthe array mounting frameshould also be noted. Itemsto observe should includethe array mounting bolts (eg.bolts rruussttiinngg) and checks toensure that the frame andmodules are firmly secured.

1. Energy generation equipment

WARNING If modules arelocated on the roof andthere is a risk of fallingduring maintenance, thenfall protection equipment(eg. harness orscaffolding) MUST beused.

Solar array


Gensets

WARNING Disable any remote orautomatic start mechanisms forgensets before commencing servicing.Also remove any keys and disconnectany starter batteries.

A petrol, LPG or diesel genset will requireregular checks of the fuel and oil levels.These will need to be topped up asrequired. In addition, regular servicingincluding complete oil changes and filterchanges will be required, at intervalsspecified in the system manual.

It is recommended that all gensets do atleast have an AC volt meter on the outputso the output voltage can be monitored. Ifthe genset is generating a voltage higher orlower than the typical 240V (230V), oroperating faster or slower than therecommended speed, the genset coulddamage household appliances while theassociated battery charger could also bedamaged or not operate correctly. Thereshould also be a run-hour meter todetermine when maintenance is due.

If you suspect that the genset is notoperating correctly, call your systemsupplier/installer or your service mechanic.

WARNING Gensets produce 240V AC.Do not open any enclosures on thegenset that will expose LIVE terminals.

Wind generators

The basic components of a pico-hydrosystem are shown in the diagram below.

With most pico-hydro generators, themaintenance required will be specific to themachine and pipe installed. The usermanual should always be consulted beforeattempting any maintenance.

The intake system should be designed tominimise the blocking of the inlet pipe byleaves, sticks or silting up. If this is aproblem then the main maintenance on apico-hydro system will be keeping the intakesystem clean and free of debris.

Pico-hydro generators


With most wind generators the maintenancerequired will be specific to the machine andtower installed.

The user manual should always beconsulted before attempting anymaintenance.

Typical checks by the system owner:• inspection of guy wires on guyed tower—

check for tension, and excessive fraying orcorrosion of guy wires;

• check the functioning of any manualffuurrlliinngg mechanisms;

• if a ccaabbllee ttwwiisstt system is used, check theamount of twist and untwist if required;and

• check that system regulators and dduummppllooaaddss are functioning in windy conditions,(refer to system supplier if things don’tlook right).

The wind generator is typically located on atower. Most of the maintenance that will berequired on the wind generator will requirethe tower to be lowered.

WARNING Do not attempt to lower aturbine tower unless you have beentrained in this procedure and never inwindy conditions.

To Load

To stream

The water flowcan be controlled

automatically

GENERATOR

TU RB I NE

SHUNTLO A DS

CONTRO LS

ISOLAT I NGVA LV E

INTAKESYSTEM

P IPEL INE

WATERSTORAGE

The batteries should belocated in accordance withmanufacturer’srecommendations. Thebattery bank must beprotected by a suitableenclosure which is onlyaccessible by appropriatelyauthorised people (eg.system owner, installer,service person). In largesheds the battery bankshould still be housed ineither a separate room orbattery box to preventunauthorised access and toseparate spark sources


2. Battery bank

The battery bankusually consists ofindividual 2V cellsconnected together insseerriieess and sometimesin ppaarraalllleell to provide abattery bank with therequired system DCvoltage and energystorage. Sometimes12V or 6V mmoonnoobblloocckkcells are used insteadof the 2V cells. Thesesystems should usebatteries which aredesigned for ddeeeeppccyycclliinngg applicationswhich are better suitedto the charging anddischarging regime.Car and truck batteriesare not suitable.

The battery bank should behoused in an enclosureaccessible only toauthorised people. Anauthorised person could bethe system owner or anappointed person.

In Australia there are twomain types of batteries usedin SPS systems:• Wet cell ffllooooddeedd batteries

(vveenntteedd cells)—in whichthe eelleeccttrroollyyttee level mustbe regularly checked.

• Sealed or gel cellbatteries—where there isno access to theelectrolyte, a regulatedvalve is incorporated andthe battery is completelysealed.

Nickel cadmium (NiCad) andnickel iron (NiFe) batteriesare rarely used for solarpower systems in Australia.

General installation requirements


from explosive ventedbattery gases. All batteryinstallations should beeither naturally or ffoorrcceeddvveennttiillaatteedd to prevent thebuild up of explosive gases.The battery enclosureshould be clean, dry andlockable to preventunauthorised access. Itshould also house only thebatteries.

Good access to the batteryterminals and electrolytefiller caps is required.Generally, batteries are

installed on a battery rack oron timber to keep them offthe floor and provide therequired access to thebatteries. There should notbe shelves or any otherequipment above thebatteries because itemsfalling from these shelvesonto the batteries couldcause a short circuit or theequipment itself could bespark generating. In addition,gases from the battery cancorrode equipment. Avoidclutter around the batteryenclosure to facilitate easy

access. The batteryenclosure must not be usedas a storage area.

Minimise the battery bank’sexposure to extremes oftemperature because thiscan reduce performance andlife. The battery bank shouldbe installed so that eachindividual battery is exposedto the same temperatureconditions. Provision shouldbe made for thecontainment of any spilledelectrolyte.

Always remember that abattery is a form of energystorage which, under certainconditions, can release itsenergy instantaneously, withexplosive consequences.The battery bank should onlybe accessible to people whounderstand its functioningand are responsible for itsmaintenance. It should beable to restrict access toother people, especiallychildren. As far as possible,the area should be animaland vermin proof. Restrictingaccess to the batteries willbe the first and often the

best safety measure.Suitable safety signs shouldcaution people of thedangers (see examplesignage above.)

The following safetyequipment should always beavailable and ready to use.People who have access tothe battery bank area shouldall be instructed in its use.• Bucket of clean water –for

rinsing off acid splashes.

• Safety goggles or faceshield – for face and eyeprotection.

• Rubber gloves – forprotection of hands.

• Eyewash bottle – forrinsing acid splashes outof eyes.

• Overalls or apron – forprotection of body andclothing from acid splash.

• Baking soda (Bicarbonate)– for neutralising acidspills.

Safety first!

Generally maintenance ofbatteries will concentrate oncorrect charging regimes,electrolyte condition, batteryterminals and overall batterysafety.

Before you start

Before you start with yourmaintenance, ensure allsafety equipment is at handand ready to use. Listedbelow is typical equipmentyou will need for thesemaintenance tasks safelyand correctly.

Safety equipment See safety first! above• HHyyddrroommeetteerr – for checking

ssppeecciiffiicc ggrraavviittyy ofelectrolyte and hencebattery charge.

• Glass bulb typethermometer – fortemperature measurementof electrolyte.

• Container with clean waterto rinse hydrometer andthermometer.

• Handheld voltmeter ormultimeter – for checkingbattery voltage.

• Appropriate tools – correctsize spanners and/orscrewdrivers withinsulated handles.

• Plastic type dishwashingscourer or similar – forcleaning battery terminalsand connectors.

• Anti oxidant coating – forcoating battery terminalsand connectors aftercleaning.

• Baking soda – for cleaningof batteries.

Checking your batteries


Maintenance of battery banks

As part of regularmaintenance, a thoroughvisual inspection of thebattery bank is required.This inspection shouldinclude:• cleanliness of batteries;• level of electrolyte, (not

required for gel cellbatteries);

• condition of batteryterminals;

• signs of any electrolyte inthe safety trays (ifprovided) or on the floor,indicating a possiblebattery leak or overfilling;

• condition of batterycontainers; and

• battery voltage level.


To maximise the life of abattery bank, it is best toensure that it is regularlyreceiving a full charge andthat its state of charge isnot allowed to fallexcessively. Please checkthe manufacturer’srecommendation with thesystem supplier—somesolar lead acid batteries cango down to a maximumddeepptthh ooff ddiisscchhaarrggee of 70-80% while, for some deepcycle lead acid batteries, therecommended maximumdepth of discharge is 50%.

Each day, at around thesame time, the battery

voltage should be checked,as this will give you a regularindication of the batterycharge condition. Decisionson energy use can be madebased on this check to avoidover discharge of the battery.Such decisions may includedelaying energy use or usingbackup generators to chargethe batteries. When youbecome more familiar withthe operation of your system,this battery check may occurless frequently.

For flooded batteries, thebattery bank also requiresan eeqquuaalliissaattiioonn charge toensure that all individual

cells in the bank are at asimilar charge. This isachieved by charging thebattery until bubbling(gassing) occurs. The periodbetween equalisationcharges is dependent uponmanufacturer and typicallyvary from 7–28 days butsome batteries can be ashigh as 90 days. Pleasecheck with your systemsupplier. If the equalisationcharge is not achieved bythe solar array then thegenset will need to be runand the charging provided bythe separate batterycharger.

Charging your batteries

The table below lists typicalvoltage levels that indicatewhether the state of chargeis good or bad for thebattery bank. This table isvalid when the batteries areat rest, (ie. no charge ordischarge is occurring). Thistable should only be used as

a guide and for accuratecharge levels the specificgravity of each cell shouldbe tested, where possible.The table below is typical offlooded wet cell batteries at25oC. At higher or lowertemperatures, correctionshould be made using

temperature correctionfactors from your batteryspecifications. If you havegel cell batteries, you canonly check the batteryspecifications from themanufacturer for anindication of state of chargefor various voltage levels.

Nominal Bad Time to start Good CautionVoltage economising or using (depending

backup charger on battery –see note)

2V <1.9 1.9-2.0 2-2.2 >2.412V <11.4 11.4-12 12-13.2 >14.424V <22.8 22.8-24 24-26.4 >28.848V <45.6 45.6-48 48-52.8 >57.6

Note: Some batteries have an equalisation or boost charge of 2.6V per 2V cell.

Checking the voltage

A typical process in shuttingdown a system and isolatingthe battery bank to make itsafe to perform themaintenance tasks wouldfollow the following steps.

WARNING Refer tosystem user manualprovided by systemsupplier for exactprocedures relevant toyour system.

1. Shut down (turn off) allllooaaddss on the systemstarting from thehousehold appliancesand working back to theinverter.

2. Disconnect (turn off) allenergy generation devicessuch as solar or windgenerators.

3. Shut down the batterybank—this would involveeither switching offcciirrccuuiitt bbrreeaakkeerrss orremoving any ffuusseess onthe battery bank. If fuses

are used, the fuse on thenegative terminal of thebattery bank should beremoved first followed bythe fuse on the positiveterminal.

4. If a switch-fuse is used,opening the switch fusedisconnects the fusesfrom the batteries.Remove the frontmechanism to prevent itbeing closed while youare working.

5. When a circuit breaker isused, either place a ‘Do


Typical battery maintenance tasks

Preparing the system forbattery maintenance

It is important to avoid clutteraround the battery bank, soremove all unnecessaryitems, leaving only safetygear and equipment requiredfor the maintenance of thebattery bank.

Before starting the batterybank maintenance, it isextremely important toiissoollaattee the battery bankfrom the system to shut thesystem down.

Follow the specifiedshutdown procedure—youshould see a sign on thewall near your equipment,spelling out this procedure.The user manual mayprovide further information.

Ensure there is plenty ofventilation in the batteryenclosure or room. If usingforced ventilation, check thatventilation systems arefunctioning correctly and areclean and unobstructed.

Before assessing thecondition of a battery, it isbest to have a fully chargedbattery.

It is also best to wait for thesolar regulator, windgenerator dump load or pico-hydro dump load to havefinished a bboooosstt cchhaarrggeebefore switching to a ffllooaattcchhaarrggee mode.

For consistency in therecording of specific gravityand voltage measurements,each cell should have apermanent numberidentification on it which isnot easily erased by wearand maintenance. Whenrecording specific gravity orvoltage, these numbers canbe used as a referencelabel.

Isolating the system for maintenance


Cleaning the cells

not operate tag’ on thecircuit breaker orphysically isolate thebattery bank by removingthe battery cabling, firstfrom the negative

terminal, then from thepositive terminal.

6. If the battery bankcontains more than onestring of cells, eachparallel string should

have its own circuitbreakers or switch-fuses,to isolate each parallelstring, as describedabove.

The battery bank is nowelectrically isolated from allenergy generating devicesand loads. It can now beworked on for maintenanceBUT remember each cell isan energy storage device-shorting of any terminals isdangerous and can cause anexplosion.

Each cell should be cleanbefore removing any fillercaps to performmaintenance ormeasurements. This willavoid contamination of thecell by dirt. To clean thecells, use either a brush toremove dry material and/ora rag dipped in a solution ofbaking soda and water andthoroughly squeezed out.

WARNING Whencleaning batteries,avoid using excesswater which may spillinto the cell and alwayswipe away fromelectrolyte filler holes.Do not allow any bakingsoda to enter the cell—even a tiny amount ofbaking soda willpermanently damagethe cell.

Checking the chargeand condition of thebattery bank

There are two methods fordetermining the state ofcharge and condition of thebattery bank. They are:• measuring the voltage of

each cell;• measuring the specific

gravity of the electrolyte ineach cell.

The measuring of specificgravity is the more accuratemeasure of a cell’s state ofcharge when used in con-junction with manufacturer’sspecifications and data.Frequent recording of thespecific gravity of your cellscan be part of their warrantyrequirements.

Using a hydrometer tocheck the specificgravity of the electrolytein a battery bank

Before use, thoroughly rinseall components of thehydrometer to avoid contami-nation of the electrolyte byforeign materials. Also rinseand clean the thermometer.Choose one cell for themeasurement of the elec-trolyte temperature. Insertthe thermometer into a cell,being careful not to touchany plate or other internalbattery structures. Leave thethermometer in the elec-trolyte while measuring thespecific gravity of the othercells in the battery bank.

Completely deflate the bulbof the hydrometer and insertthe tube into the electrolyte,releasing the bulb to drawup the electrolyte.

To measure specific gravity, ahydrometer is used. A glassthermometer is used tomeasure the cells’temperatures. Generally theelectrolyte is drawn up by thehydrometer and a specificgravity reading is taken fromthe ffllooaatt level. A typical deepcycle cell which is fullycharged will have a specificgravity of approximately1.250 at 25°C. (Confirm thevalue for your battery fromthe system supplier orbattery manufacturer). Areading less than 1.250indicates a lower state of

charge within the battery. Thethermometer is requiredbecause the specific gravitychanges with temperature.A higher temperaturedecreases the specificgravity; a lower temperatureincreases the specific gravityof the electrolyte. To convertyour actual measurement toa value at the standardtemperature of 25°C, acorrection factor must beapplied. This information willbe supplied in your batterymanual. Some manufacturerssupply graphs showing therelationship between specific

gravity, temperature andeffective state of charge

Measure the specific gravityof electrolyte in each cell,(see above) and record in thelogbook. Apply thetemperature correction to thereadings and check withbattery data to estimate thestate of charge. If thespecific gravity measurementof any cell is more than0.025 below the averagespecific gravity of the batterybank, then an equalisationcharge should be applied andthe battery bank rechecked.


Voltage measurement

Once the battery bank isisolated, use a volt meter tomeasure the voltage acrossthe complete battery bankand across each cell andrecord in the logbook. If anycell is more than 10% higheror lower than the averagecell voltage, an equalisationcharge should be performedand the battery bankrechecked.

Specific gravity measurement

Hydrometer Thermometerwith stopper

Squeeze the bulb anddeflate, squirting electrolytecarefully back into cell.

Repeat this three to fourtimes to ensure that thehydrometer is at the sametemperature as theelectrolyte.

Now fill the hydrometer andhold it vertically, ensuring itsfloat is floating in theelectrolyte. Now read theelectrolyte level off the float.Return the electrolyte to thecell. Record the reading inthe logbook. Rinse thehydrometer in fresh waterand test the next cell,following the same procedureuntil all cells are tested.


Neutralising acid spills

To neutralise an acid spill, use a solution ofbaking soda and water. Mix half a cup ofbaking soda in approximately 10 litres ofwater. For larger spills, use a mop to cleanup the spill. This solution can also be usedfor cleaning the cells and battery terminals.

WARNING When neutralising acid spillsdo not allow any baking soda solutionto enter the battery cells—even a tinyamount of baking soda willpermanently damage the cell.

Topping up the electrolyte

When batteries are charging and gassing,the battery is losing water. To top up theelectrolyte, use distilled water (or de-ionisedwater) and fill the battery via the electrolytefiller hole until the correct level is reached.There are several types of indicators to showthe level is correct. These indicators varyfrom simple markings on the side of thebattery case, indicating high and low levelsto systems which use a float indicator.

Check the manufacturer’s instructions forthe type of indicator used in your batteries.

It is preferable to add distilled water whenthe battery charge is high as the addition ofwater will decrease the charge of thebattery.

WARNING Use onlydistilled water for rinsinghydrometer and thermo-meter. Use of bore watermay introducecontaminants which aredamaging to batteries.

Reading the electrolytespecific gravity

If the battery terminals areshowing signs of corrosion,or have not had an anti-oxidising coating applied,they may require cleaning.This will involvedisconnecting the batteryleads and cleaning both thebattery terminal posts andthe battery lead connectors.

It is important to ensurethe battery bank hasbeen isolated beforeattempting todisconnect any leads.

Battery terminal corrosion isoften seen as a whitecrystalline or powderymaterial around or on thebattery terminals. A heavilyoxidised terminal will have avery dark, almost blackcoating. If this is between

mating surfaces of theconnectors and posts it willneed to be cleaned.

Before disconnecting,carefully wipe most of thecorrosion off using a brushor rag with the baking sodasolution, then carefullydisconnect the battery leadconnector from the batteryterminal post and clean bothusing a plastic scourer.Once clean, apply the anti-oxidising coating followingthe manufacturer’srecommended procedureand reconnect the batterylead connector onto thebattery terminal post.Repeat this procedure foreach terminal, as required,being careful not tocontaminate the electrolytewith any foreign material.

WARNING Do not useany metal files or otherharsh abrasives (eg.sand paper) to removecorrosion or oxidisationfrom terminals or postsas this may cause apoor fit when terminalsare reconnected.


Cleaning the battery terminals Differences for gel celltype batteries

Gel cell batteries requirespecial attention to themethod used for charging asovercharging of a gel celltype battery may causeirreversible damage to thebattery. Consult with systemsupplier forrecommendations oncharging of gel cell typebatteries. Controllers andchargers should be set tothe gel cell mode for bestperformance.

NOTE Overcharging a gelbattery can lead tobattery gases escapingwith a similar risk ofexplosion as for wetlead-acid batteries.

Maintenance of gel cellbatteries only relates to thebattery terminals andconnections. Themaintenance required forthese is the same as for wetcell flooded batteries.

The state of charge of thebattery can only bedetermined by measuringvoltage of the battery, whenthere has been nodischarging or charging ofthe battery for at least 15-30 minutes, and referring totables supplied by themanufacturer.


The inverter

Typically the system owneris only aware that thegenset has not started whenthe batteries have reached alow voltage.

When inspecting theinverter, remove any excessdust from the unit andespecially from the hheeaatt--ssiinnkkss.. This should only bedone with a dry cloth orbrush. Check that “vermin”have not infested theinverter eg. typical signs ofthis include spider webs onventilation grills or wasps’nests in heat sinks. Contactsystem suppliers if yoususpect vermin are insidethe inverter.

The iinnvveerrtteerr should beinstalled in a clean, dry, andventilated area which is sep-arated from, and not directlyabove, the battery bank.While the system is operat-ing the following operationalchecks can be made:• check that the inverter is

functioning correctly byobserving LLEEDD indicators,metering and/or other dis-plays on the inverter

• check to see if theinverter’s ssttaanndd--bbyy mmooddee(if present) is functioningcorrectly. This can be doneby turning off all loads andappliances operating onthe system. Once in stand-by mode, switch anappliance on and theinverter should startalmost immediately.

• check that any controlfunctions for rreemmootteessttaarrttiinngg of diesel genset(if installed) are operating.Ensure that the diesel

genset is starting andstopping at correct batteryvoltage levels as specifiedby manufacturer (refer tosystem supplier or inverteroperating manual).

NOTE The third check can bedifficult to undertake as itcan require disconnecting allcharging sources (eg. PVarray) and turning onsufficient appliances toforce the battery voltage todecrease to the set voltagefor starting the genset. Itcould also be simulated byraising the voltage setting sochecking that the generatordoes start at the highervoltage, which is close tothe actual voltage of thebattery bank. The exacttesting method will dependon the actual set-up of thesystem and probably mightonly be able to beundertaken by a suitablyqualified person eg. thesystem supplier/installer.

3. Balance of systems (BOS)

BBaallaannccee ooff ssyysstteemmss include:• regulators (or controllers)

for the solar array, windgenerator and pico-hydrogenerator;

• inverters;• all interconnecting power

cables and control cablesbetween the individualcomponents to create thesystem;

• all switchboards,protection equipment andmetering/monitoringequipment.

This equipment requireslittle maintenance. If thisequipment requires anymaintenance or repair it willgenerally need to be done byqualified personnel and the

supplier should be contactedfor advice.


Each of the renewableenergy charging sources: PVarray, wind generator andpico-hydro generator willrequire their own specificcharge regulator (orcontroller). Any regulatorshould be installed in aclean, dry and ventilatedarea.

The regulator is an electronicdevice that controls thevoltage of the chargingsources (solar, wind, hydro)energy output to charge thebattery bank appropriately.The regulators are designedto disconnect or reduce thecharge current when presetvoltages are reached.Typically there are boostvoltage settings and floatvoltage settings.

Inspect and check thefunctioning of the regulatorto ensure that any indicatorsor meters are correctlyoperating for the variousregulator modes. In the caseof a PV system, check thatwhen the batteries are fullycharged and it is sunny, thatthe solar regulator ischanging into float mode.

The wind generator and pico-hydro regulator do operatedifferently to the solarregulator. If you have a windgenerator or pico-hydrogenerator the regulators

used are known as sshhuunnttregulators and will requireadditional componentsknown as dummy loads,typically a bank of resistivecoils. When the battery bankreaches the preset voltage,the current from thegenerator source is“shunted” into the dummyload.

WARNING These shuntscan get very hot andshould not be touched.

During maintenance checks,inspect the functioning of theregulator to ensure that anyindicators or meters arecorrectly operating for thevarious regulator modes.

In general correct operationof the regulator(s) can onlybe observed in certain

conditions. This is achievedby observing that the chargecurrents from the differentsources (solar, wind or pico-hydro) are either removed orreduced when specifiedvoltages are obtained. Thiscould be observed when thevoltage of the batteryreaches a certain point, thisindicates that the battery isfully charged and theregulators go from boost tofloat mode.

Full operation tests mightneed to be undertaken by asuitably qualified person eg.the system supplier/installer.

When inspecting theregulators:• look for any loose wiring

on the terminalconnections. If they areloose follow the shutdownprocedures for the systembefore tightening theconnections or contactyour installer.

NOTE Loose connectionscan cause hhoott jjooiinnttss andpossibly fire.

• remove any excess dustfrom the unit andespecially from the heat-sinks. This should only bedone with a dry cloth orbrush.

Regulator(s)

Check for any breaks ordeterioration in exposedconduit and wiring. Alsoinspect connections for anysigns of corrosion and/orburning. If any damage isnoticed contact the systemsupplier/installer.

Inspect the condition of theconduit and wiring from the:• charging source to its

regulator;

• regulator to battery bank;• inverter to battery bank;• genset to battery charger• battery charger to battery

bank• inverter and genset to AC

switchboard.

An example of poorly wired,unprotected andunsupported cabling fora charger


Battery chargers

The maintenance required forbattery charging equipmentis similar to that required forinverters.

Check that the charger doescharge the battery bankwhen the genset isoperating. If it does notappear to be operatingcorrectly check the output

voltage of the genset. (if voltmeter has been installed). Ifgenset is not producingcorrect output voltage, thenthe battery charger will notoperate correctly. If thegenset is OK then contactsystem supplier/installer.

Any battery charging equip-ment should be installed in a

clean, dry and ventilatedarea.

When inspecting the charg-ing equipment remove anyexcess dust from the unitand especially from any heat-sinks. This should only bedone with a dry cloth orbrush.

System wiring

Correctly installed switch-boards and wiring should notrequire maintenance.

The licensed electricalcontractor who installed thesystem should have checkedall existing wiring andswitchboards.

As part of your systeminspection, the switchboardsand visible wiring can be

visually inspected for signsof corrosion and/or burning.If either is apparent, consulta licensed electricalcontractor to identify andrectify possible faults.

All safety switches, rreessiidduuaallccuurrrreenntt ddeevviicceess ((RRCCDDss)which detect current leakageto earth should be tested bypressing the test buttonprovided.

Residual current device(RCD)

Switchboards and wiring

Wind generator meter

Pico-hydro meter

If a system has metering forthe wind generator output, byobserving the output currentregularly any loss of perform-ance may be noticed. Thecurrent will be dependent onthe amount of wind butthrough regular observationon windy days you will noticethat the generator is produc-

ing suitable current. Any sig-nificant changes in outputwhich are noticed can beinvestigated. Causes couldinclude wiring problemsand/or problems with systemregulators – refer to the sys-tem supplier for advice if yoususpect either of these prob-lems.

If a system has metering forthe pico-hydro output, byobserving the output currentregularly, any loss of per-formance may be noticed.Typically the output of a pico-hydro generator is constant.Any significant changes inoutput which are noticed canbe investigated. The mostcommon causes for loss ofoutput would be blockage of

the inlet pipe thereby reduc-ing the water flow or thewater flow has reduced inthe stream. Other causescould include: blocked jets inthe turbine or wiring prob-lems and/or problems withsystem regulators – refer tothe system supplier foradvice if you suspect eitherof these problems.


4. Interpretation of monitoring equipment

Often a system owneris unaware of aproblem until suddenlythe inverter turns offand the house has nopower. Typically thesystem will include aback-up genset so thatthis can be operated toprovide power to thehouse but this will benoisy, expensive,environmentallyunfriendly andinconvenient.

As a minimum, theAustralian Standardrecommends that yoursystem should include a voltmeter for measuring thesystem DC voltage and acurrent meter from each ofthe charging sources (solar,wind and/or pico-hydro).Regularly monitoring thesemeters will help to identify aproblem before the point isreached where the inverterswitches off due to lowbattery state of charge(reflected by low batteryvoltage).

Solar array meter

If a system has metering forthe solar array output, byobserving the output currentregularly any loss of perform-ance may be noticed. Therewill be some variation in thiscurrent due to changes inaammbbiieenntt temperature, sea-son of the year, angle of thesun and the level of solarradiation iinncciiddeenntt on themodules. To minimise theseeffects, this observationshould be done on fine,

cloud-free days at aroundnoon. Any significant changesin output that are noticed canbe investigated. The mostcommon causes for loss ofoutput would be excessivedirt on the modules or partialshading of the array. Othercauses could include wiringproblems and/or problemswith system regulators – referto the system supplier foradvice if you suspect eitherof these problems.


Other monitoringSystem voltage meter

If a system has metering forthe system DC voltage(battery voltage), byobserving the voltageregularly at a similar time ofday any loss of performancemight be noticed. Thesystem voltage will be higherwhen being charged andlower when there is nocharge and there are loadspresent. A good time toobserve the voltage is firstthing in the morning and atnight time. If the voltage islower than expected thenthis could indicate that:• the system is not being

charged effectively; or• the energy usage has

increased, thereby usingmore than the system isproducing; or

• battery cells are gettingold and either losingefficiency or a cell mighthave failed.

If you are unable todetermine the problemcontact your system supplierfor advice.

Many of the inverters andregulators on the markettoday are mmiiccrroopprroocceessssoorrcontrolled and thereforeallow other monitoringfeatures. This can includethe ability to data-log yoursystem for a period of timeand even allow for rreemmootteemmoonniittoorriinngg via modems andphone lines.

These will typically includeall the meters mentionedabove but will often includemeasuring the amount ofenergy being produced andconsumed daily.

If your system includes thistype of monitoring, loggingthe daily energy flow (in andout) will help determinewhether your system isoperating correctly and willoften alert you to a problembefore it causes a systemfailure.

In particular monitoring theenergy generated each dayprovides more informationthan simply observing thecharge current. If this figurereduces substantially, it willindicate there is a problemin the charging of thesystem.

By observing the amount ofenergy used each day, youwill then know if your energyconsumption has increased.

By comparing the amount ofenergy generated with theamount of energyconsumed, you will then seewhether you are:• under-using the system—

that is, the system isproducing more energythan you are using. (Note:due to system losses, youshould always producemore than you use)

• using more than thesystem is producing andtherefore you may soonhave flat batteries and asystem failure.Alternatively, you mayneed to run the gensetand battery charger tocompensate.

Your system supplier shouldtrain you to make effectiveuse of the monitoringequipment.


C: Grid-connected solar PV systems

The typical GC system willinclude:• PV modules;• inverter; and• BOS equipment- including

meters, switching equipmentand system wiring.

These sections provide anoverview of the maintenancerequirements for these pieces ofequipment. In particularly, howdo you know that your GC systemis working?

C: Grid-connected solar PV systems 29

1. PV solar modules

The solar array (a number ofsolar modules mountedalongside each other) isoften thought to bemaintenance free. This canbe the case in manysituations, however, withoccasional maintenance andinspection, the performanceof all the solar modules inthe array can be assured.

The most commonmaintenance task for solarmodules is the cleaning ofthe glass area of the moduleto remove excessive dirt.

WARNINGTypically modules arelocated on a roof hencethere is a risk of falling.When performingmaintenance, someform of fall protectionequipment (eg. harnessor scaffolding), MUSTbe used.

In most situations cleaningis only necessary duringlong dry periods when thereis no rain to provide naturalcleaning. To remove a layerof dust and dirt from themodules, simply wash thepanel with water. If themodule has thick dirt orgrime, which is harder toremove, wash with warmwater and a sponge.Washing the modules issimilar to washing glasswindows but detergentsshould not be used.

After the modules have beencleaned, a visual inspectionof the modules can be doneto check for defects in themodules such as cracks,chips and discolouration. Ifany obvious defects arefound, note their location inthe system logbook, so theycan be monitored in thefuture in case furtherdeterioration affects themodules’ output. In mostcases the module output willnot be affected.

When inspecting the solarmodules, the condition ofthe array mounting frame (ifused) should also be noted.Items to observe shouldinclude the array mountingbolts (eg. bolts rusting) andchecks to ensure that theframe and modules arefirmly secured.

An example of a PV panelmaintenance log sheet isshown in Annex 2.


3. Balance of system

These items generallyrequire very littlemaintenance but whenmaintenance is beingperformed on other parts ofthe system then thefollowing should beundertaken:

• keep the inverter cleanand minimise thepossibility of dust beingblown over the equipment—clean with dry clothwhen required;

• ensure the unit is not“infested” by vermin; and

• check that the inverter isfunctioning correctly byobserving LLEEDD indicators,metering and/or otherdisplays on the inverter.

An example of an inverterlog sheet is shown inAnnex 2.

These items generallyrequire very littlemaintenance but whenmaintenance is beingperformed on other parts ofthe system then thefollowing should beundertaken: • check that all

interconnections andcables/conduits aremechanically secure;

• check that all switchesand circuit breakers areoperating correctly; and

• confirm any meters areoperating correctly.

Typically grid-connected PVsystems are using “plug”cables between the solarmodules in the array andwhen mounted on the roofthese are often hiddenbehind the solar modules.Therefore the only cablesthat can be inspected will bethe cables and/or conduits:• from the array to the

inverter and • the inverter to the

switchboard.

An example of a BOS logsheet is shown in Annex 2.

2. Inverters


4. How do I know my system is working?

With a grid-connected PVsystem there are no movingparts. During the day, whenthe sun is shining on themodules, they are quietlyproducing electricity which iseither being consumed inyour house or exported tothe grid.

Since it’s so quiet, how doyou know it’s working?

It is recommended that as aminimum, your systemshould include a meter thatrecords either the amount ofenergy being generated bythe modules or the amountbeing exported to the grid.

If it is only measuring theproduction then you couldrecord the meter reading inthe morning and then againthat evening. The differencein the reading will determinethe day’s production.

If it is only measuring whatis being supplied to the grid,and you are consuming allyour generated power, thenthis meter will not move veryoften. In this case, turn offall appliances in the houseand then observe whetherthat meter is moving.

Some systems will includemeters that indicate exactlywhat is being produced atany time, while otherinverters will constantlymonitor and record theenergy generated. It isimportant that your systemsupplier explains to you howto know if your system isworking.

Power output display


Annex 1: SPS maintenance log sheets

The following log sheetsspecify all the maintenancethat should be performed oneach of the system

components and thesystem. Those maintenanceitems that are shaded ingrey are only to be

undertaken by a trainedservice person. They havebeen included to ensure thelog sheets are complete.

Solar array log sheetDate Name Cleaned Array Array Array Array Array

modules structure cabling cabling output output OK mechanical electrical voltage current

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Battery bank log sheetDate Date Date

Name

Battery voltage

Ambient temperature

Cell 1

S G

Electrolyte temperature

Corrected SoC

Cell volts

Water used in litres

……..

Cell x

S G

Electrolyte temperature

Corrected SG

Cell volts

Water used in litres

Interconnections OK?

Battery cases OK?

Comments


Annex 1: SPS maintenance log sheets 35

Balance of systems log sheetDate Date Date

Name

Battery voltage

Regulator

Item clean

Insects removed

Cables connections OK

Functioning OK

Inverter

Item 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 OKAlso if there are other generating items eg. wind generator then the log sheet should includespace for all regulators.

Genset log sheetDate Name Genset Oil Fuel Oil Air Comments

total hours changed filter filter filterrun

Note: Ticked when changed

Wind generator log sheetDate Name Integrity Bearings Mechanical Electrical Comments

of tower lubricated/ integrity wiringstructure changed of blades integrity

& tail

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Pico-hydro log sheet


Annex 2: GC maintenance log sheets

Solar array log sheetDate Name Cleaned Array Array Array Array Array

modules structure cabling cabling output output OK mechanical electrical voltage current

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Annex 2: GC maintenance log sheets 39

Time Weather Comments


Inverter log sheetDate Name Cleaned No Cable Inverter Comments

inverter insects connections operating OK correctly

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BOS log sheetDate Name Cable All Cable Meter Comments

connections switches connections operating OK and CB’s OK correctly

operating

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Annex 3: Glossary 41

deep cycling suitable forlarge charge anddischarge cycles

depth of dischargepercentage discharge of abattery.

dump loads a load toprevent the current fromovercharging the battery

electrolyte solution in abattery that stores energyand allows the current topass

energy generation devicesPVs, wind turbine, gensetor pico-hydro generator

equalisation overchargingto ensure all cells haveequalised specific gravityand therefore each cell isfully charged

exhaust gases containnoxious fumes

exhaust sparks sparks infumes which can causefire

float sealed cylinder insidehydrometer

float charge intermittentcharging of the battery ata voltage specified bymanufacturer also knownas intermittent topping upof the battery

flooded A battery with wetelectrolyte within thebattery case and aroundthe electrodes

forced ventilated poweredby a fan

fuels usually diesel, LPG orpetrol

240V 240 volts AC – alethal voltage

AC alternating currentambient surroundingarray A number of PV

modules electricallyinterconnected

balance of systemsincludes regulators,inverters, cables, controlboard and protectionequipment

bi-carbonate soda bakingsoda – sodiumbicarbonate

boost charge A chargingcycle that ensures thebattery reaches close tofully charged also knownas “topping up thebattery”

BOS Balance of Systembrake prevents the turbine

from turningcable twist A mechanism in

a wind turbine where thecables in the tower of thewind turbine can twist oneway then another – workingon the theory that the windturbine will approximatelyturn equally clockwise andanticlockwise so that thecable does not twist tootight

cells a single battery unit(usually 2 volts)

circuit breakers anelectrical protection devicethat automaticallyswitches to off whenoverloaded

DC direct current

furling turning the blades toavoid the wind

fuses protection devicesthat break the overload byburning a wire inside theircasing—must be replacedwhen operated

GC connected to the mainspower grid

gel the electrolyte in thebattery is a gel as distinctto a liquid solution

gensets a diesel, LPG orpetrol 240V generator

guy wires supports holdingtower of wind tower inplace

heat-sinks finned steel tohelp dissipate heat

hot exhaust pipe from afuel genset and can causeburns

hot joints poor electricalcontact causing heating

hydrogen a volatile gasgiven off during chargingof batteries

hydrometer device formeasuring specific gravity

incident strikinginsulated prevents electrical

shortingintegrity components

working correctly and inharmony

inverter converts DCcurrent into 240 V AC

isolate cut off electricallylead-acid the electrolytic

compound and theelectrodes

LED light-emitting diode

Annex 3: Glossary


live carrying an electricalcurrent

loads appliances drawingelectricity

logbook book recordingdata sampled by the user

low voltage (LV) 120V DC,50V AC or greater

pico-hydro generatorsconverts kinetic energy inwater to electrical energy

microprocessor usingcomputer chips

modules photovoltaic cellsconnected in series andsometimes parralel toprovide required power

monoblock battery cellsconnected in series andlocated in one case –often provided as a 6V or12V battery eg. same asin your car

noise can damage earsopen-circuit voltage across

PV array when there’s noload

parallel electricallyconnected side by side

photovoltaic electricityproduced from thesunlight

RCD residual current deviceregulators controls the

current to the batteriesremote monitoring reading

data in another locationusing a modem

remote starting ability tostart the genset from aremote switch

residual current devicescircuit breaker triggered byan electrical short toearth

rusting can be caused bygalvanic reaction betweendissimilar metals

series electrically connectedin a line

SG specific gravityshorting when two opposite

charged terminals or cable(eg. + and –) areconnected together

shunt electrical currentbypasses the load and issupplied to an alternativeload

specific gravity densityrelative to water

SPS stand-alone powersystem – not connected tothe grid

stand-by mode inverter isswitched on, waiting for aload

terminals positive andnegative batteryconnectors

tower structure holding thewind turbine

trackers follows the path ofthe sun

vented open to the airwind generators converts

wind energy into electricalenergy

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 safetyrails 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

�� Cleaned

�� Check structure

�� Cabling mechanical

�� Cabling electrical

�� Output voltage

�� Output current

�� Log completed

Balance of System

�� Battery voltage

�� Switches/CBs

Connections

�� Regulator

�� Inverter

�� Charger

�� Control board

�� Cleaned

�� Bugs removed

�� Cables

�� Working OK


Battery

�� Battery voltage

�� Interconnections

�� Ambient temp

�� Log completedfor each cell

�� SG

�� Temperature

�� SoC

�� Voltage

�� Water

�� Case OK

Genset

�� Run hours

�� Oil change

�� Fuel filter

�� Oil filter

�� Air filter


Wind Generator

�� Guys

Pico-hydro

�� Intake cleaned


• What is the manufacturer’srecommendation for amaximum depth ofdischarge of thebatteries?

• What is the recommendedtime between equalisationcharges?

• If using sealed batteries,obtain chart showingbattery voltage in relationto state of charge.

• Obtain tables or graphsthat relate specific gravityreadings and temperatureto state of chargeinformation.

• What is the maximumcharging current?

Annex 5: Information to be obtained from system supplier or manufacturers

Solar PV Systems: Users maintenance guide

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