SamlexsolarSCC 30AB Manual

8/6/2019 SamlexsolarSCC 30AB Manual

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30 AmpSolar ChargeController

SCC-30AB

Owner'sManual

Please read thismanual be oreoperating yourcharge controller.


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1. Sa ety Instructions .............................................................................................. 3

2. General Description o PV / Solar System .......................................................... 5

3. General in ormation - Batteries ...................................................................... 15

4. Introduction and Features ............................................................................... 24

5. Construction, Layout and Controls .................................................................. 30

6. Installation and Operation .............................................................................. 34

7. Troubleshooting ............................................................................................... 41

8. Specifcations .................................................................................................... 43

9. Warranty ........................................................................................................... 44

INDEX


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1SAFETY INSTRUCTIONS

Please read these instructions before installing or operating the Charge Controller toprevent personal injury or damage to the Charge Controller.

General Installation and wiring compliance

Installation and wiring must comply with the local and National ElectricalCodes and must be done by a certifed electrician.

Preventing electrical shock The negative system conductor should be properly grounded. Grounding

should comply with local codes. Disassembly / repair should be carried out by qualifed personnel only. Disconnect all input and output side connections be ore working on any

circuits associated with the Charge Controller. Turning the on/o control onthe Charge Controller to o position may not entirely remove dangerousvoltages.

Be care ul when touching bare terminals o capacitors. The capacitors may

retain high lethal voltages even a ter the power has been removed. Dischargethe capacitors be ore working on the circuits.

Installation environment The Charge Controller should be installed indoor only in a well ventilated,

cool, dry environment Do not expose to moisture, rain, snow or liquids o any type.

Preventing fre and explosion hazards

Working with the Charge Controller may produce arcs or sparks. Thus, theCharge Controller should not be used in areas where there are in ammablematerials or gases requiring ignition protected equip ment. These areas mayinclude spaces containing gasoline powered machinery, uel tanks, batterycompartments.

Precautions when working with batteries Batteries contain very corrosive diluted sulphuric acid as electrolyte.

Precautions should be taken to prevent contact with skin, eyes or clothing.

Batteries generate hydrogen and oxygen during charging resulting inevolution o explosive gas mixture. Care should be taken to ventilate thebattery area and ollow the battery manu acturers recommendations.

Never smoke or allow a spark or ame near the batteries.


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1SAFETY INSTRUCTIONS

Use caution to reduce the risk o dropping a metal tool on the battery. It couldspark or short circuit the battery or other electrical parts and could cause anexplosion.

Remove metal items like rings, bracelets and watches when working withbatteries. The batteries can produce a short circuit current high enough to weld aring or the like to metal and thus cause a severe burn.

I you need to remove a battery, always remove the ground terminal rom thebattery frst. Make sure that all the accessories are o so that you do not cause aspark.

Charge Controller related It is to be ensured that the input voltage ed to the Charge Controller does not

exceed 50 VDC to prevent permanent damage to the Charge Controller. Ensurethat the maximum Open Circuit Voltage Voc o the 12 V nominal Solar Panel / the Solar Array is less than 50 V. I two 12 V nominal Solar Panels are being usedin series to make a 24 V nominal Solar Array, make sure that the maximum OpenCircuit Voltage Voc o each o the 12 V Panels is less than 25 V.

Do not exceed the maximum current rating o 30 A. The Short Circuit Current othe Solar Array should be less than 30 A

Do not exceed a battery voltage o 24V (nominal) . Do not use a battery less than12V.

Charge only 12, or 24 volt Lead-Acid batteries when using the standard batterycharging programs or Ni-Cd batteries when DIP Switch number 2~4 is in the ONposition.

DO NOT short circuit the PV array or load while connected to the controller. Thiswill damage the controller.

The controller should be protected rom direct sunlight. Ensure adequate spaceor air ow around the controllers ace plate.

Do not install in a sealed compartment with batteries. Never allow the solar array to be connected to the controller with the battery

disconnected. This can be a dangerous condition with high open-circuit solarvoltage present at the terminals.

Use only copper wire with minimum 75C insulation rating and between 10 AWG(5.2 mm 2) and 14 AWG (2.1 mm 2) gauge.

The Negative system conductor should be properly grounded. Grounding shouldcomply with local codes.


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2GENERAL DESCRIPTION OF PV / SOLAR SYSTEM

What is Photovoltaic (PV)?

The word photo-voltaic is derived rom two di erent words; the word photos,rom the Greek, meaning light and the word voltaic developed rom the name o the

Italian scientist, Volta, who studied electricity. This explains what a PV system does: itconverts light energy rom the sun into electrical energy.

What is in a Photovoltaic (PV) system?Non Grid-tied PV / Solar System

PV/Solar Panel (Module) or Array

Charge Controller

Battery

DC-AC Power Inverter

To ACLoads

Fig. 2.1. Non Grid-tied PV SystemBlock Diagram

Fig. 2.1 shows a Block Diagram o a typical non-grid tied Photovoltaic (PV) Systemwith its main components. It consists o a PV / Solar Panel (Module), Charge Controller,Batteries and Power Inverter. The PV / Solar Panel (Module) or Array converts thesolar light energy into DC electrical energy. The Charge Controller conditions the DCelectrical voltage and current produced by the PV / Solar Panel (Module) or Array tocharge a battery. The battery stores the DC electrical energy so that it can be usedwhen there is no solar energy available (night time, cloudy days etc). DC loads can bepowered directly rom the PV / Solar Panel (Module) / Battery. The inverter convertsthe DC power produced by the PV / Solar Panel (Module) / stored in the battery intoAC power to enable powering o AC loads.


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Grid-tied PV / Solar System

Fig. 2.2 shows a Block Diagram o a typical Grid-tied PV / Solar System. In this system,the Solar Panels (Modules) / Arrays directly eed to an inverter and the inverter isconnected to an Electricity Transmission and Distribution System (re erred to as theElectricity Grid) such that the system can draw on the Grids reserve capacity in timeso need, and eed electricity back into the Grid during times o excess production.

Solar Array

ChargeController/Protection

DC-AC Power Inverter

To ACLoads

Power toand rom grid

Two-way Metering

Fig. 2.2 Grid-tied PV / Solar System Block Diagram

In order to sa ely transmit electricity to your loads and to comply with your powerproviders grid-connection requirements, you may need the ollowing additionalitems:

Power conditioning equipment Sa ety equipment Meters and instrumentation.


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PV / Solar Cell

12cm

Fig. 2.3. PV / Solar Cell

The basic element o a PV System is the photovoltaic (PV) cell, also called a Solar Cell.An example o a PV / Solar Cell made o Mono-crystalline Silicon is shown in Fig. 2.3.This single PV / Solar Cell is like a square but with its our corners missing (it is madethis way!).

Theory o Operation o PV / Solar Cell

Sunlight (photons)

External circuit

Encapsulate seal

Top electrical contact

P-Type material(Boran-doped Silicon)

N-Type material(Phosphorous-doped Silicon)

P/N junction

Base contact

Figure 2.4: Construction and Working o PV / Solar Cell

A PV / Solar Cell is a semiconductor device that can convert solar energy into DCelectricity through the Photovoltaic E ect (Conversion o solar light energy intoelectrical energy). When light shines on a PV / Solar Cell, it may be re ected, absorbed,or passes right through. But only the absorbed light generates electricity.


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When light enters the PV / Solar Cell, some o the Photons (packets o electro-

magnetic wave energy) rom the light energy are absorbed by the semiconductoratoms. The energy o the absorbed light is trans erred to the negatively chargedelectrons in the atoms o the solar cell. With their new ound energy, these electronsescape rom their normal positions in the atoms o the semiconductor photovoltaicmaterial and become part o the e lectrical ow, or current, in an electrical circuit. Aspecial electrical property o the PV / Solar Cell a built-in electric feld provides the

orce, or voltage, needed to drive the current through an external load, such as alight bulb.

To induce the built-in electric feld within a PV / Solar Cell, two layers o somewhatdi ering semiconductor materials are placed in contact with one another (See Fig. 2.4).One layer is an N-type semiconductor (e.g. Phosphorus doped Silicon) with an abundanceo Electrons, which have a Negative electrical charge. The other layer is a P-typesemiconductor (e.g. Boron doped Silicon) with an abundance o Holes, which have aPositive electrical charge.

Although both materials are electrically neutral, N-type silicon has excess Electrons andP-type silicon has excess Holes. Sandwiching these together creates a P-N Junction at theirinter ace, thereby creating an electric feld.

When N-type and P-type silicon come into contact, excess electrons move rom theN-type side to the P-type side. The result is a buildup o Positive charge along theN-type side o the inter ace and a buildup o Negative charge along the P-type side.

Because o the ow o electrons and holes, the two semiconductors behave like a battery,creating an electric feld at the sur ace where they meet the P/N Junction. The electricalfeld causes the electrons to move rom the semiconductor toward the Negative sur ace,where they become available to the electrical circuit. At the same time, the Holes move inthe opposite direction, toward the positive sur ace, where they await incoming electrons.

The electrical current is ed to the external load through the top electrical contact sur ace(normally in the orm o a grid) and the bottom base contact.

The Open Circuit Voltage Voc o a PV /Solar Cell is just under 0.6 V

Factors A ecting Voltage and Current Output o the PV / Solar Cell

The amount o electric current generated by photon excitation in a PV / Solar Cell ata given temperature is a ected by the incident light in two ways:

By the intensity o the incident light.

By the wavelength o the incident rays.


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The materials used in PV / Solar Cells have di erent spectral responses to incident

light, and exhibit a varying sensitivity with respect to the absorption o photons atgiven wavelengths. Each semiconductor material will have an incident radiationthreshold requency, below which no electrons will be subjected to the photovoltaice ect. Above the threshold requency, the kinetic energy o the emittedphotoelectron varies according to the wavelength o the incident radiation, buthas no relation to the light intensity. Increasing light intensity will proportionallyincrease the rate o photoelectron emission in the photovoltaic material. In actualapplications, the light absorbed by a PV cell will be a combination o direct solarradiation, as well as di used light bounced o o surrounding sur aces. PV / Solar

Cells are usually coated with anti-re ective material so that they absorb the maximumamount o radiation possible.

The output current o the PV / Solar Panel (Module) can increase due to what isknown as the Edge o the Cloud E ect . As the sun moves into a hole between theclouds, your solar panels will see ull direct sunlight combined with re ected light

rom the clouds! They will absorb more energy than they could on a cloudless day!Thus, a actor o 1.25 times the Short Circuit Current Isc is recommended when sizingthe current capacity o the Charge Controller

The output current o the PV / Solar Cell has a positive Temperature Coe fcient Theoutput current increases with the rise o temperature. However, it is negligible lessthan 0.1 % / C o the Short Circuit Current Isc

The output voltage o the PV / Solar Cell has a Negative Temperature Coe fcient The output voltage increases with decrease in temperature. For example, a SiliconCell has a Temperature Coe fcient o 2.3 mV / C / Cell. Hence, during cold winterdays, the voltage will rise. Hence, as a Thumb Rule, the voltage rating o the ChargeController should be sized as 1.25 times the Open Circuit Voltage rating Voc o the PV

/ Solar Panel (Module) to ensure that the Charge Controller is not damaged due to

over-voltage.


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PV Cell Types

PV cells are most commonly made o Silicon, and come in two varieties, crystalline andthin-flm type, as detailed in Table 2.1

Cell types include Mono-crystalline Silicon, Poly-crystalline Silicon, Amorphous Silicon(a-Si), Gallium Arsenide (GaAs), Copper Indium Diselenide (CuInSe2, CIS), CadmiumTelluride, or a combination o two materials in a tandem cell.

Bulk type / Wa er-based (Crystalline)

Mono Crystalline Si Poly Crystalline Si Poly Crystalline Band

Pros High e fciency High e fciency withrespect to price -

Cons Increased manu acturing cost caused by thesupply shortage o silicon -

Thin flm type

Amorphous Si CIGS CdTe Polymer organic

Pros Low price

Low price

Able to automateall manu acturing

process

Low manu acturing

Can be more e fcient(still in research)

Cons Low e fciency Low e fciency

Table 2.1 PV Cell Types

PV Module / Panel and PV Array

To increase their utility, a number o individual PV cells are interconnected togetherin a sealed, weatherproo package called a Panel (Module). For example, a 12 V Panel(Module) will have 36 cells connected in series and a 24 V Panel (Module) will have 72PV Cells connected in series

To achieve the desired voltage and current, Modules are wired in series and parallelinto what is called a PV Array. The exibility o the modular PV system allowsdesigners to create solar power systems that can meet a wide variety o electricalneeds. Fig. 2.5 shows PV cell, Panel (Module) and Array.


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Cell

Module

Array

Figure 2.5. PV cell, Module and Array

The cells are very thin and ragile so they are sandwiched between a transparentront sheet, usually glass, and a backing sheet, usually glass or a type o tough plastic.

This protects them rom breakage and rom the weather. An aluminum rame is fttedaround the module to enable easy fxing to a support structure.

The picture in Fig. 2.6 shows a small part o a Module with cells in it. It has a glassront, a backing plate and a rame around it.

Aluminumrame

Glassront

BackingSheet

PV Cell

Fig. 2.6. Construction o a typical Mono-crystalline PV / Solar Panel


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Bypass Diodes

As mentioned, PV / Solar cells are wired in series and in parallel to orm a PV / SolarPanel (Module). The number o series cells indicates the voltage o the Panel (Module),whereas the number o parallel cells indicates the current. I many cells are connectedin series, shading o individual cells can lead to the destruction o the shaded cell or othe lamination material, so the Panel (Module) may blister and burst. To avoid such anoperational condition, Bypass Diodes are connected anti-parallel to the solar cells as inFig. 2.7. As a consequence, larger voltage di erences cannot arise in the reverse-currentdirection o the solar cells. In practice, it is su fcient to connect one bypass diode or

every 15-20 cells. Bypass diodes also allow current to ow through the PV module whenit is partially shaded, even i at a reduced voltage and power. Bypass diodes do not causeany losses, because under normal operation, current does not ow through them.

+-

load

bypass diodesA K

Figure 2.7: Parallel PV cell with bypass diodes

Current (I), Voltage (V) and Power (P) Curves o a PV / SolarPanel (Module) and how the PV / Solar Panel (Module) is rated -Voc , Vmp , I sc , Imp , Pmax

Fig. 2.8 Current (I), Voltage (V) and Power (P) Curves


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2GENERAL DESCRIPTION OF PV/SOLAR SYSTEM

A Current (I) versus Voltage (V) Curve o a PV / Solar Module (I-V Curve) shows thepossible combinations o its current and voltage outputs. A typical I-V curve or a 12 VModule is shown at Fig. 2.8.

The power in a DC electrical circuit is the product o the voltage and the current.Mathematically,

Power (P) in Watts (W) = The Current (I) in Amperes (A) X the Voltage (V) in Volts(V) i.e. W = V X A

A PV / Solar Cell or a Panel (Module) produces its maximum current when there isno resistance in the circuit, i.e. when there is a short circuit between its Positive andNegative terminals. This maximum current is known as the Short Circuit Current and isabbreviated as I sc. When the Cell / Panel (Module) is shorted, the voltage in the circuitis zero.

Conversely, the maximum voltage occurs when there is a break in the circuit. This iscalled the Open Circuit Voltage (V oc ). Under this condition, the resistance is infnitelyhigh and there is no current, since the circuit is incomplete. Typical value o the open-circuit voltage is located about 0.5 0.6 V or Crystalline Cells and 0.6 0.9 V orAmorphous Cells.

These two extremes in load resistance, and the whole range o conditions in betweenthem, are depicted on the I-V Curve. Current, expressed in Amps, is on the verticalY-axis. Voltage, in Volts, is on the horizontal X-axis.The power available rom a photovoltaic device at any point along the curve is justthe product o Current (I) in Amps (A) and Voltage (V) in Volts (V) at that point and isexpressed in Watts. At the short circuit current point, the power output is zero, sincethe voltage is zero. At the open circuit voltage point, the power output is also zero, butthis time it is because the current is zero.

Maximum Power Point and Rated Power o PV / Solar Panel (Module)There is a point on the knee o the I-V Curve where the maximum power output

is located and this point is called the Maximum Power Point (MPP). The voltage andcurrent at this Maximum Power Point are designated as Vmp and Imp.

The values o Vmp and Imp can be estimated rom V oc and I sc as ollows:

Vmp (0.75 0.9) V oc

Imp (0.85 0.95) I sc


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2GENERAL DESCRIPTION OF PV/SOLAR SYSTEM

The rated power o the PV / Solar Module in Watts (Pmax) is derived rom the abovevalues o voltage Vmp and current Imp at this Maximum Power Point (MPP):

Rated power in Watts, Pmax = Vmp X Imp

Example o I-V Curve and Ratings o a 12 V PV / Solar Panel

Fig. 2.9. Example o I-V Curve and Ratings o a 12 V PV / Solar Panel

The I-V Curve or a typical 12 Volt PV / Solar Panel is shown in Fig. 2.9.

This Maximum Power Point in the example curve given above is where Vmp is 17 Volts,and the current Imp is 2.5 amps. There ore, the rated or the maximum power Wmax inwatts is 17 Volts times 2.5 Amps, or 42.5 Watts.

Standard Test Conditions (STC) or Speci ying PV / Solar Modules

The I-V curve is also used to compare the per ormance o PV / Solar Modules.The curve is, there ore, generated based on the per ormance under Standard TestConditions (STC) o sunlight and device temperature o 25 C. It assumes there isno shading on the device. Standard sunlight conditions on a clear day are assumedto be 1,000 Watts o solar energy per square meter (1000 W/m 2 or 1 kW/m 2). This issometimes called one sun, or a peak sun. Less than one sun will reduce the currentoutput o the PV device by a proportional amount. For example, i only one-hal sun

(500 W/m 2) is available, the amount o output current is roughly cut in hal .


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3GENERAL INFORMATION: BATTERIES

Types o BatteriesThere are several di erent types o battery chemistry including liquid Lead-Acid,

Nickel-Iron (NiFe), Nickel-Cadmium (Ni-Cd), alkaline, and gel-cell. Batteries are eithersealed or vented. Simply, there are only two principal types o batteries: starting anddeep-cycle.

Starting batteries are designed or high cranking power, but not or deep cycling.Used as energy storage, they will not last long in a deep cycle application. Startingbatteries use lots o thin plates to maximize the sur ace area o the battery. This allowsvery high starting current but lets the plates warp when the battery is cycled. Thistype o battery is not recommended or the storage o energy in solar applications.However, they are recommended as starting battery or the back-up generator.

Deep cycle batteries are the type o battery best suited or use with inverters. Thephysical dimension o the plates is thicker and the active material that holds thecharge is denser to increase cycle li e. The deep cycle type o battery is designed tohave the majority o their capacity used be ore being recharged. They are available inmany sizes and in either non-sealed or sealed types.

Usual battery inverters are optimized or use with lead acid batteries that havea nominal voltage o 2.0 volts per cell. Ni-Cd/NiFe batteries (also called alkalinebatteries) have a nominal cell voltage o 1.2 volts per cell. The nominal voltage o aNi-Cd / NiFe battery bank can be made the same as a lead acid bank just by jugglingthe number o cells (10 cells or 12 volts, 20 cells or 24 volts and 40 cells or 48 voltsystems). However, the Ni-Cd/NiFe battery bank must be charged to a higher voltageto ully recharge and will drop to a lower voltage during discharging compared to asimilarly sized lead acid type battery.

State o Charge (SOC) o the Battery

One important parameter that defnes the energy content o the battery is the Stateo Charge (SOC). This parameter indicates how much charge is available in the batteryre erring to its capacity. It is the ratio o the di erence o the rated capacity in AmpereHours (Ah) and the net Ah discharged or charged since the last ull SOC. For example,in a 100Ah capacity battery, i the net Ah discharged is 20 Ah, then the SOC is 80% ie(100 Ah 20 Ah) divided by 100 Ah. SOC is also called Residual Capacity.

Generally, the voltage o the battery cell is taken as the basis or calculating SOCor the remaining capacity. Results can vary widely depending on actual voltage

level, temperature, discharge rate and the age o the cell and compensation orthese actors must be provided to achieve a reasonable accuracy. Fig 3.1 shows therelationship between the Open Circuit Voltage and the Residual Capacity at constant


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temperature and discharge rate or a high capacity Lead Acid cell. Note that the cellvoltage diminishes in direct proportion to the remaining capacity.

Fig 3.1 SOC versus Open Circuit voltage

The Lead-Acid Batteries

A basic equivalent circuit o the Lead-Acid battery is modeled by a voltage sourcewith an equilibrium voltage (V E) in series with an internal resistor (R in) (see Fig 3.2). Itmust be noted here that this confguration can describe only a current state becausethe magnitude o V E and R in are not actually constant, but is unction o manyparameters such as state o charge (SOC), temperature, current density, and aging othe battery.

V B

V in

I B

R in

V E R load V BV B

V in

I B

I B

R in R in

V EV E R load R load

Fig 3.2. Basic equivalent circuit o the Lead-Acid battery or a current state


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Furthermore, it is to consider that these parameters depend also on the currentdirection (charging or discharge). When the battery were at rest or under open-circuitcondition V B = VE. When current is drawn rom the battery, the voltage will be lowerthan V E. When current is owing into the battery, the terminal voltage will be higherthan V E. For example, at each moment during discharge phase the terminal voltagecan be derived as ollow:

VB =VE Vin (3.1)=VE Rin IB (3.2)

where: VB

= terminal voltage [V]VE = equilibrium voltage [V]

Vin =internal loss voltage [V]Rin =internal resistance [ ]IB =discharge current [A]

Obviously, higher discharge current results in reduction o the terminal voltage.There ore, to speci y the state o the battery by the battery voltage, discharge current

should be also measured.In case o discharge, the minimum voltage level acceptable or a Lead-Acid battery

is defned as discharge voltage threshold . Falling below this threshold is called deepdischarge , with which the battery may su er damage. In case that the battery isle t longer a ter deep discharge, lead o the support structure is converted to lead-sulphate in rough-crystalline orm, which during charging can be only bad or cannotbe converted again anymore. As a result, the battery loses a part o its storagecapacity; besides loss o support structure arises as well.

In practice, harm ul deep discharge is to be prevented: the loads will be compulsorydisconnected rom battery as soon as the discharge voltage threshold is reachedi.e. with the help o a so-called deep discharge protection (DDP). This threshold isbasically given in the data sheets by the manu acturer or di erent discharge currents.Pre erably, the value o this threshold should depend on the discharge current. Therelation between the discharge current and the voltage during discharge or the Lead-Acid battery is presented in Figure 3.3.


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Fig 3.3: Discharge characteristic curves

Figure 3.3 shows the discharge profle o a typical battery type at several constantcurrent rates. The typical end-o -discharge voltage at these discharge rates canalso be noticed where the voltage starts to drop steeply. Moreover, the end-o -discharge voltage varies between 1.75-1.9 V, depending on the battery type and thedischarge current. Higher service capacity is obtained at the lower discharge rates.At higher discharge rates, the electrolyte in the pore structure o the plate becomesdepleted, and it cannot di use rapidly enough to maintain the cell voltage. However,

intermittent discharge, which allows time or electrolyte di usion will improve theper ormance under high discharge rates

Gassing

With 2.3 V 2.4 V, namely the so-called Gassing Voltage , gas is developed at theelectrodes in the battery, by which the water is decomposed into hydrogen (H 2)and oxygen(O 2). Both gases mix together in the battery providing detonating gas(explosive!) and escape through ventilation opening in the vent plug. With thegassing, the battery also loses water, which must be reflled according to maintenance

within regular intervals. The gas is the unwelcome secondary reaction o the chemicalconversion during charging because current is consumed or the electrolysis and,there ore, the storage e fciency o the battery is made worse unnecessarily.


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Figure 3-5: Cycle li e as a unction o deep o discharge

Battery capacity

Previously, the storage capacity o a battery is expressed in Ah (Ampere-hours)showing how many hours a certain current can be taken rom the charged batteryuntil the battery is discharged, i.e. until the battery voltage drops to the dischargevoltage threshold.

Nowadays, it might be more avorable to express a battery capacity in dischargeableenergy, namely Wh (Watt-hours) or kWh (kilowatt-hours). However, these two ways oexpressing the battery capacity are equivalent because they are related via the batteryvoltage, i.e. Ah V = Wh.

Un ortunately, the capacity o a battery is not a constant quantity, but dependson the amount o discharge current. The manu acturers, there ore, give the ratedcapacity o their batteries always with regard to a certain discharge current.

The so-called Rated Battery Capacity re ers to the capacity o the battery under givenstandard conditions: it is common practical to defne the rated capacity at 20 C bydischarging the battery with a Rated Battery Current (I20 ), which re ers usually to aconstant current, with which the battery will be completely discharged in 20 hours.Some battery manu acturers indicate the 100-hour discharge capacity or batteriesintended or PV applications. When comparing such capacity, it should be rememberedthat, or a given battery, the 100-hour capacity is always at least 15 % higher than the20-hour capacity .


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Besides, battery capacity is also a ected by the temperature: it alls by about 1 % perdegree below about 20 C. Moreover, extreme high temperatures accelerate aging,sel -discharge and electrolyte usage.

Requirements or solar batteries

Typical requirements or the battery to be used in long term storage are: low specifc kWh-cost, i.e. the stored kWh during the whole li e o the battery long li etime high overall e fciency

very low sel -discharge low maintenance cost easy installation and operation high power

- Specifc kWh-cost

Usually, it re ers to a sum o investment and operation costs o the battery divided bythe stored kWh (kWh ) during its whole li e. This cost is, thus, in uenced by the

batterys li etime.

- Li etimeThe li etime o the battery should be long, especially in order to keep the specifc kWh-cost and the installation cost low, particularly in remote areas.

- Overall e fciency

The overall e fciency ( ) is derived rom charge or coulombic e fciency ( I) andvoltage e fciency ( V):

= I V (3.3)

The coulombic e fciency is usually measured at a constant discharge rate re erring tothe amount o charge able to be recalled rom the battery (Q D) relative to the amountput in during charging (Q C). Sel -discharge will a ect columbic e fciency.

I=QD / QC (3.4)

The battery will usually need more charge than was taken out to fll it back up to its

starting point. Typical average coulombic e fciencies are 80 85 % or stand-alonePV systems, with winter e fciencies increasing to 90 95 %, due to higher coulombice fciencies when the battery is at a lower state o charge and most o the chargegoing straight to the load, rather than into the batteries.


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The voltage e fciency is determined by the average discharge voltage (V D) andaverage charging voltage (V C). VC is lower than V D particularly by internal resistanceo the battery.

V=VD / VC (3.5)

The overall e fciency ( ) should be as high as possible, to be able to pass the biggestproportion o the energy in the battery, which is generated by the PV generatorsystem, urther to consumers.- Sel -discharge

The battery discharges itsel even without load connected. This e ect is caused bysecondary reactions at its electrodes and proceeds aster with higher temperature orin older batteries. Thermodynamic instability o the active materials and electrolytes aswell as internal and external short-circuits lead to capacity losses, which are defned assel -discharge. This loss should be small, particularly in respect o annual storage.- Maintenance cost

The maintenance, e.g. water reflling in case o Lead-Acid batteries, should be keptas low as possible.- Easy installation and operation

Since batteries are o ten used also by non-experts, easy installation and operationare, there ore, avorable.- Power

In special cases, battery must be highly loadable or a short time, e.g. at the start odiesel generators or in case o momentary power extension o PV systems.

There are many types o batteries potentially available or use in stand-alone PVsystems. Use ul data o available batteries given in Table 3.1 shows approximated

values and are provided as a guideline.

Table 3-1: Comparison between selection criteria o available batteries

Type Cycle li e until 80% DOD

CoulombicE fciency

I [%]

Sel -discharge[%/month]

Temp. range[C]

Lead Acid 500...1500 > 80 34 -15...+50Ni-Cd 1500...3500 71 620 - 40...+45Ni-Fe 3000 55 40 0+40


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Since many values are dependent on charge and discharge conditions, they havenot been standardized or PV applications and or test purposes until now. There ore,the comparison between batteries and selection o the most suitable one or eachapplication are not easy. Due to particular operating conditions with PV applicationsin practical operation, the cycle li e given by manu acturer (and in Table 3.1) orcycling load can be reduced more than hal .

According to Table 3.1, it ollows that in most cases, the Lead-Acid batteries would bethe best choices or PV applications. The selection o suitable choices should be basedon specifc application.

Temperature Compensated Battery ChargingTemperature a ects the rate o chemical reactions in the batteries as well as the

rate o di usion and the resistivity o the electrolyte. There ore, the chargingcharacteristics o the battery will vary with temperature. This is nearly linear andthe Voltage Coe fcient o the temperature change can vary rom -3 mV / C / Cellat 50 C to -5 mV / C / Cell at -10 C. Please note that the Voltage Coe fcient othe temperature change is negative which means that as the temperature rises, thecharging voltage is required to be reduced and as the temperature is decreased, the

charging voltage has to be increasedThe Absorption Voltage set point is normally specifed at 25 C. Battery temperatures

o ten vary up to 15 C rom the 25 C re erence in PV Systems. The Absorption Voltageor a 12 V sealed battery must then be adjusted as ollows:

Battery Temperature Absorption Voltage

40 C 13.8V

25 C (Re erence) 14.1V (Re erence)

10 C 14.5V

In case temperature compensation is not provided, the warmer battery at 40 C willbegin to heat and outgas at 13.8 V and will continue to overcharge until the non-compensated Absorption Voltage set point is reached (14.1 V). In cooler temperatures,the 10 C battery will experience severe undercharging resulting in sul ation.


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4INTRODUCTION & FEATURES

The SCC-30AB is a Series Type o PWM (Pulse Width Modulation) Charge Controller.

It is based on an advanced design using a microcontroller or digital accuracy and ullyautomatic operation. It can be used or 12V or 24V systems or solar charging . ThePWM battery charging has been optimized or longer battery li e. The unit is designed

or user- riendly operation. Please take the time to read this Owners Manual andollow the instructions step by step to help you make ull use o the charging system.

Features

Advanced microcontroller based, high per ormance design or digital accuracy

and ully automatic and intelligent operation Dual voltage capability can be used with 12 V / 24 V Solar Systems 30 A charging capacity enables use o up to 360 W o 12 V or 720 Watts o 24 V

Solar Panels Series Mode PWM (Pulse Width Modulation) charging design or low loss higher

e fciency charging and longer battery li e 4 Stages o charging or 100% return o capacity and long battery li e Bulk,

Absorption, Float and Equalization Stages

Choice o 8 sets o Absorption / Float / Equalization voltage settings to enablecomplete and sa e charging o a wide range o Lead Acid / Ni-Cd Batteries Convenient 2 X 16 character LCD Display with backlight or display o operating

in ormation and data. Additional LED indication or displaying the chargingstages

Optional remote Battery Temperature Sensor (BTS) or temperaturecompensation to ensure improved charging o batteries that experience widertemperature variations during the year

MOSFET based reverse current blocking or night-time battery discharge

prevention. This allows much lower losses as compared to Diode based blocking Specially designed or RVs, boats and trucks allows convenient and aesthetic

ush mounting on walls / panels Industry leading warranty

Requirements o Battery Charging in PV Systems

Batteries in PV Systems are commonly subject to abusive conditions that are generallydue to:

Under charging due to low sun peak hours Excessive charging in high sun peak hours Inappropriate or ine ective charge control or the battery technology


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The individual or combined e ects o sun peak hour changes, poor charge control

and the daily load changes can be potentially damaging to the battery. Cheapercharge control strategies such as simple on/o PV array shedding (Non PWM control)will generally provide the battery with su fcient charging current to complete theBulk Charge Phase which will return the battery to 80% State o Charge. A terthe Bulk Charge Phase, the Taper or Absorption Charge Phase is very important inpreventing stratifcation, hard sul ation and pre-mature capacity loss.

PWM Battery Charging

PWM (Pulse Width Modulation) battery charging is the most e fcient and e ectivemethod or recharging a battery in a solar system. The PV array is connected to thebattery through a series or parallel (called Shunt) connected MOSFET Switch. ThePWM control circuit switches on and switches o the MOSFET Switch at a requencyo several hundred cycles per second. Thus, instead o a steady output rom thecontroller, it sends out a series o short charging pulses to the battery like a veryrapid on-o switch. The controller constantly checks the state o the battery todetermine how long (wide) the pulses will be. In a ully charged battery with no load,it may just tick and send very short pulses to the battery. In a discharged battery,the pulses would be very long and almost continuous. The controller checks the state

o charge on the battery between pulses and adjusts itsel each time. This techniqueallows the current to be e ectively tapered and the result is equivalent to constantvoltage charging

Series and Shunt Type o Charge Controller

When the MOSFET Switch is connected in series with the PV Array and the battery,the Controller is called Series Type. When it is connected in parallel across the PV Array

/ the Battery, it is called Shunt Type. In Series Type, the MOSFET Switch is kept openwhen the battery is ully charged. The PV Array stops supplying current during thisperiod. In the Shunt Type, when the battery is ully charged, the MOSFET Switch iskept closed to shunt (divert) the ull Short Circuit Current o the PV Array away romthe battery.

Advantages o Series Type o Charge Controller

A series Type o Charge Controller has the ollowing advantages over a Shunt Type:

Power systems experience temporary over voltage conditions. For example, when

lightning strikes, extremely high electrostatic energy is discharged. This energyinduces damaging high voltage transients in exposed and un-protected electricalcircuit elements like cables etc and these high voltage transients are ed to theelectrical devices and cause damage i the device is not adequately protected.


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PV Systems and associated cabling are installed in exposed locations and hence,

they are more prone to the damaging e ects o high voltage transients. Large PVSystems employ numerous lightning protection devices like Lightning Rods, SurgeSuppressors, shielded cables etc. However, in small PV systems, these protectionsare seldom incorporated. Because there is less system level protection, small PVCharge Controllers are more susceptible to damage by high voltage transients.Transient Voltage Surge Suppressors (TVSS) are used to protect the input andoutput sections o the Charge Controller. The TVSS clamps the high voltageo the transient to a sa e level. The Clamping Voltage is seen by the MOSFETand temporarily stresses the MOSFET. In a Series Type o Charge Controller,

the MOSFET Switch is located between the input terminals and the battery.Hence, the voltage seen across the MOSFET Switch during high voltage transientcondition is lower and is equal to the Clamping Voltage o the TVSS minus thebattery voltage. This produces lower stress. On the other hand, in a Shunt TypeCharge Controller, the MOSFET Switch sees the ull Clamping Voltage and,there ore, it is stressed to a higher degree.

Lesser switching noise. During charging, the Shunt MOSFET Switch experienceshigher level o stress because it is in a high temperature reverse bias standoposition

The voltage applied across the Series MOSFET Switch is lesser and hence, itexperiences lesser stress and is, there ore, more reliable

A Shunt Type requires a Schottky Diode in series with the battery to prevent shortcircuiting o the battery during the time the MOSFET switch shunts the PV Array. In aSeries Type, this Schottky Diode is not required. Elimination o the Schottky Diode inthe Series Type has the ollowing associated advantages:

Lower voltage drop, less heating and consequent lower losses Reverse leakage through the Schottky is eliminated

Battery Charging AlgorithmSelecting the best method or charging your battery together with a good

maintenance program will ensure a healthy battery and long service li e. Although theSCC-30ABs battery charging is ully automatic, the ollowing in ormation is important

or getting the best per ormance rom your SCC-30AB Charge Controller and battery.


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Four Stages o Solar Charging

Fig. 4.1 represents the 4 stages o charging used in the SCC-30AB

V O L T A G E

TIME

NIGHTNIGHT

4FLOAT

3EQUALIZE

2PWM

ABSORPTION1BULK

CHARGING

Fig. 4.1 Solar Charging Stages

1. Bulk Charging: In this stage, the battery will accept all the current provided by thesolar array. The value o this current will be equal to the Short Circuit Current Isc othe solar array

2. PWM Absorption: When the battery reaches the Absorption Voltage, the PWMbegins to hold the voltage constant. This is to avoid over-heating and over-gassingthe battery. The current will taper o to sa e levels as the battery becomes more ullycharged.

3. Equalization : Many batteries beneft rom a periodic boost charge to stir theelectrolyte, equalize the cell voltages, and complete the chemical reactions (Seeadditional details on Equalization given below)

4. Float : When a battery becomes ully charged, dropping down to the oat stagewill provide a very low rate o maintenance charging while reducing the heatingand gassing o a ully charged battery. When the battery is ully recharged, there canbe no more chemical reactions and all the charging current is turned into heat andgassing. The purpose o oat is to protect the battery rom long-term overcharge.From the PWM absorption stage, charging is dropped to the oat voltage. This istypically 13.4V.


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Equalization

Routine equalization cycles are o ten vital to the per ormance and li e o a battery particularly in a solar system. During battery discharge, sul uric acid is consumedand so t lead sul ate crystals orm on the plates. I the battery remains in a partiallydischarged condition, the so t crystals will turn into hard crystals over time. Thisprocess, called lead sul ation, causes the crystals to become harder over time andmore di fcult to convert back to so t active materials.

Sul ation rom chronic undercharging o the battery is the leading cause o batteryailures in solar systems. In addition to reducing the battery capacity, sul ate build-up

is the most common cause o buckling plates and cracked grids. Deep cycle batteriesare particularly susceptible to lead sul ation.

Normal charging o the battery can convert the sul ate back to the so t activematerial i the battery is ully recharged. However, a solar battery is seldom completelyrecharged, so the so t lead sul ate crystals harden over a period o time. Only a longcontrolled overcharge, or equalization, at a higher voltage can reverse the hardeningsul ate crystals.

In addition to slowing or preventing lead sul ation, there are also other benefts o equalization o the solar system battery. These include:

-Balance the individual cell voltages

Over time, individual cell voltages can dri t apart due to slight di erences in the cells.For example, in a 12 cell (24V) battery, one cell is less e fcient in recharging to a fnalbattery voltage o 28.8 volts (2.4 V/c). Over time, that cell only reaches 1.85 volts, whilethe other 11 cells charge to 2.45 volts per cell. The overall battery voltage is 28.8V, butthe individual cells are higher or lower due to cell dri t. Equalization cycles help tobring all the cells to the same voltage.

-Mix the electrolyte

In ooded batteries, especially tall cells, the heavier acid will all to the bottom o thecell over time. This stratifcation o the electrolyte causes loss o capacity and corrosiono the lower portion o the plates. Gassing o the electrolyte rom a controlledovercharging (equalization) will stir and remix the acid into the battery electrolyte.

NOTE: Excessive overcharging and gassing too vigorously can damage the battery plates and cause shedding o active material rom the plates. An equalization that istoo high or or too long can be damaging. Review the requirements or the particular battery being used in your system.


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When to Equalize

The ideal requency o equalizations depends on the battery type (Lead Calcium,Lead-Antimony, etc.), the depth o discharging, battery age, temperature, and other

actors.

One very broad guide is to equalize ooded batteries every 1 to 3 months or every5 to 10 deep discharges. Some batteries, such as the L-16 group, will need more

requent equalizations.

The di erence between the highest cell and lowest cell in a battery can also indicate

the need or equalization. Either the specifc gravity or the cell voltage can bemeasured. The battery manu acturer can recommend the specifc gravity or voltagevalues or your particular battery.


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5CONSTRUCTION, LAYOUT & CONTROLS

GeneralSCC-30AB is designed or ush mounting on a wall / panel. The controls and

indications are built on the Front Panel ace plate that has 4 countersunk holes orush mounting (Fig. 5.1). All the electronics, DIP switches or settings, terminal stripor connections or the PV Array and the Battery and terminal or the optional Battery

Temperature Sensor (BTS) are mounted on a PCB that is in turn mounted at the backo the ace plate (Fig. 5.2). For ush mounting on the wall / panel, a suitable cutout isrequired to be made in the wall / panel to accommodate the PCB at the back o theunit. As the components at the back o the unit will be hidden and protected behind

the wall / panel, the components at the back o the unit are exposed and do not havea protective cover. PLEASE HANDLE THE UNIT CAREFULLY TO PREVENT ANY DAMAGETO THE EXPOSED COMPONENTS AT THE BACK OF THE UNIT.NOTE: As the unit will be connected to 12 V / 24 V Nominal Solar Array / battery system, there isno likelihood o electrical shock.

Fig. 5.1 Front Panel o SCC-30AB

Fig. 5.2. Back view o SCC-30AB


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Display o BULK and FLOAT voltage setting value

Display o Equalization Voltage, Equalization Time and Equalization Interval Display o heat sink (the ront panel metal plate acts as the heat sink) temperature

and battery temperature through the optional Battery Temperature Sensor (BTS).* NOTE: As the display is not capable o showing negative values, battery temperature below 0 C will not

be displayed. Voltage compensation will, however, be carried out even below 0 C.

Fault Messages

PUSH: Display Select

Amp Watts BatV0.0 0.0 12.0

Amp-Hours0 Ah

Total Amp-Hours0 Ah

Mode: ChargerState: Bulk

Bulk Float14.0V 13.4V

EQU EQU-T CYCLE14.2V 1hr 28day

Heatsink BTS25oC 25oC


PUSH: Display SelectPUSH: Display Select




Charger / Conversion Control ModeDisplay Flow

Fig. 5.3. LCD Display Flow

*


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Fault Messages

The LCD displays might have the ollowing ault messages when SCC-30AB stopsoperating.

Table 5.1. Fault messages

Display Description Cause o Fault

Alarm: OCOver Current Over Current The current exceeds 45 A

Alarm: OT Heat Sink over temperature Heat sink temperature exceeds 90 CAlarm: CPF00

Link Master error Display Panel errorThe CPU is not able to exchange data

with the Display Panel

Back o the Unit

The back o the unit (Fig 5.2) has the ollowing input / output connections and DIPSwitches or various settings.

Table 5.2. Control Terminal Connection (At the back o the unit)

Name DescriptionPV+ Connecting terminal or Solar Array PositivePV Connecting terminal or Solar Array NegativeBattery + Connecting terminal or Battery cable PositiveBattery Connecting terminal or Battery cable Negative

DIP Switch 1ON* Selection o battery voltage or 12V system

OFF Selection o battery voltage or 24V system

DIP Switch 2,3, 4 Battery charge control mode: Battery charging algorithm

DIP Switch 5ON Selection o Auto EqualizationOFF* Selection o Manual Equalization

BTS Battery Temperature Sensor or temperature compensation *NOTE: Factory preset condition


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6INSTALLATION & OPERATION

25 mm

2 5 m m

2 5 m m

25 mm

2 5 m m

25 mm 25 mm

2 5 m m

6 mm

6 m m

6 m m

6 mm

190 mm

1 0 8 m m

- Cut the wall / panel along the dotted linewith a jig saw.

- This will create a pocket in the wall / panelor fush mounting o Charge Controller SCC-30AB.

Outline o the ront panel

Fig. 6.1. Drawing or making the cut-out in the wall / panel

2. Make sure the PV currents will not exceed the ratings o the SCC-30AB.

3. The connections to the SCC-30AB terminals are shown in the drawing at Fig. 5.2.A barrier type o Terminal Strip has been provided or connecting the PV array andthe battery. M-4 screws with clamping washers are used to make the connection. A

at or a #2 Philips head screw driver may be used to tighten these screws. Tighteneach terminal clamping screw to 20 inch-pounds o torque. The distance between thebarriers is 9 mm and a standard Spade Type o terminal lug meant or # 8 Stud and

AWG #10 AWG #12 wire may be used at the end o the wires to be connected tothese terminals. 4 such terminal lugs are provided with the unit or ease o installation

4. Set the DIP Switch 1 or the voltage system, set the DIP Switch 2, 3, 4 or batterycharging algorithm.

5. Connect the BATTERY frst. Be care ul that bare wires do not touch the metal caseo the controller.

The BATTERY must be connected be ore the Solar Panel (Module)/Array toproperly start the microcontroller, activate protections & guide installation.

A battery below 9 volts may not start the microcontroller properly. Make sure thebattery is charged be ore installing the system.


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6. Connect the Solar Panel (Module)/Array next. The green LED indicator will light i

the Solar Panel (Module)/Array is connected during the daytime and the Solar Panel(Module)/Array is wired correctly.

Remember that the Solar Panel (Module)/Array will generate power whenever insunlight. Also, be care ul not to short circuit the Solar Panel (Module)/Array whileconnected to the controller, since this will damage the controller.

7. For most e ective surge protection, it is recommended that the Negative systemconductor be properly grounded.

Dip Switch Settings

Five DIP Switches permit the ollowing parameters to be adjusted at the installationsite:

DIP Switch 1ON* Selection o battery voltage or 12V system

OFF Selection o battery voltage or 24V system

DIP Switch 2, 3, 4 Battery charge control mode: Battery charging algorithm (see Table 6.1)

DIP Switch 5ON Selection o Auto Equalization

OFF* Selection o Manual Equalization*NOTE: Factory preset condition

Battery Charging Notes

The SCC-30AB manages many di erent charging conditions and systemconfgurations. Some use ul unctions to know are given below.

Solar Overload: Enhanced radiation or edge o cloud e ect conditions cangenerate more current than the controllers rating. The Budget will reduce thisoverload up to 130% o rated current by regulating the current to sa e levels. I thecurrent rom the solar array exceeds 150%, the controller will interrupt charging.

Battery Types: The SCC-30ABs standard battery charging programs are suitable ora wide range o Lead-Acid battery types. These standard programs are select by DIPSwitch 2~4.


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Standard Battery Charging Programs

The SCC-30AB provides 8 standard battery charging algorithms (programs) thatare selected with the DIP Switches. These standard algorithms are suitable orLead-Acid batteries ranging rom sealed (Gel, AGM, maintenance ree) to oodedto L-16 cells and Ni-Cd etc.Table 6.1 below summarizes the major parameters o the standard charging algo-rithms. Note that all the voltages are or 12V systems. For 24 V system, multiplythe voltages by 2.

All values are 25C (77F).Table 6.1. Standard Battery Charging Programs

Note: All the voltages given in the Table are for 12V Battery System.For 24V Battery Systems multiply the voltage values by 2.

DIPSwitches

(2-3-4)

A

Battery Type

B

PWM AbsorptionVoltage

C

FloatVoltage

D

EqualizeVoltage

EEqualize

Time(hours)

FEqualizeInterval(days)

O -O -O 1 Sealed 14.0 13.4 None - -

O -O -On 2 Sealed 14.1 13.4 14.2 1 28O -On-O 3 - Sealed 14.3 13.4 14.4 2 28O -On-On 4 - Flooded 14.4 13.4 15.1 3 28On-O -O 5 - Flooded 14.6 13.4 15.3 3 28On-O -On 6 - Flooded 14.8 13.4 15.3 3 28On-On-O 7 - L-16 15.0 13.4 15.3 3 14On-On-On 8-Ni-Cd 16.0 14.5 None - -

A. Battery Type These are generic Lead-Acid wet cell (Lead Antimony, LeadCalcium), sealed AGM, sealed Gel Cell and Ni-Cd battery types.

B. Voltage This is the PWM Absorption Stage with constant voltage charging. ThePWM Absorption voltage is the maximum battery voltage that will be heldconstant. As the battery becomes more charged, the charging current taperso until the battery is ully charged.

C. Float Voltage When the battery is ully charged, the charging voltage will bereduced to 13.4 volts or all battery types. It will be 14.5V or Ni-Cd.

D. Equalization Voltage During an equalization cycle, the charging voltage willbe held constant at this voltage.

E. Equalization Time The charging at the selected equalization voltage will

continue or this number o hours.F. Equalization Interval Equalizations are typically done once a month. Most o thecycles are 28 days so the equalization will begin on the same day o the month. Itcan be set by DIP Switch 2~4 or di erent interval days. Each new cycle will be resetas the equalization starts so that a setting day period will be maintained.


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Equalization ProcedureStandard Equalization Programs

Both automatic and manual equalizations can be per ormed using the standardcharging programs.

Manual Equalization

The SCC-30AB is shipped with the DIP Switch set or manual equalization only.This is to avoid an unexpected or unwanted automatic equalization. In the ManualMode, the pushbutton is used to both start and stop a manual equalization. Holdthe pushbutton down or 5 seconds to start and 3 seconds to stop an equalization(depending on whether an equalization is in progress or not).

There are no limits to how many times the pushbutton can be used to start and stopequalizations. Equalizations will be terminated automatically as per the chargingprogram selected i the pushbutton is not used to manually stop the equalization.

Automatic Equalization

I the equalization DIP Switch 5 is moved to the ON position, the equalizations willbegin automatically as per the charging program selected. Other than starting, theautomatic and manual equalizations are the same and ollow the standard chargingprogram selected. The push button can be used to start and stop equalizations in boththe manual and automatic mode.

Typical Equalization

The automatic equalizations will occur at the selected charging program rom DIPSwitch 2~4. When equalization begins (Auto or Manual), the battery charging voltageincreases up to the Equalization Voltage Veq . The battery will remain at Veq or thetime specifed in the selected charging program.

The equalization process will continue until the voltage has been held above thebulk setting or a cumulative period o one, two or three hours. A second manualequalization cycle can be started with the pushbutton, i needed.

I the equalization cannot be completed in one day, it will continue the next dayor days until fnished. A ter equalization is completed, charging will return to PWMAbsorption.


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Temperature Compensated Battery Charging

An optional Battery Temperature Sensor (BTS) is available or temperaturecompensated battery charging. The BTS consists o a temperature sensing probe thatis installed on the + battery post. A pair o 10 t. wires (marked + & -) connect thetemperature sensing probe to the 2 terminals marked BTS at the back o the unit. (Fig.5.2).

As the battery gets warmer, the gassing increases. As the battery gets colder,it becomes more resistant to charging. Depending on how much the batterytemperature varies, it is important to adjust the charging or temperature changes.

Various voltage set points given in the specifcations are indicated at a re erencetemperature o 25 C / 77 F.

There are three battery charging parameters that are a ected by temperature:

PWM Absorption

This is the most important part o charging that is a ected by temperaturebecause the charging may go into PWM absorption almost every day. I the battery

temperature is colder, the charging will begin to regulate too soon and the batterymay not be recharged with a limited solar resource. I the battery temperature rises,the battery may heat and gas too much.

Equalization

A colder battery will lose part o the beneft o the equalization. A warmer batterymay heat and gas too much.

Float

Float is less a ected by temperature changes, but it may also undercharge or gas toomuch depending on how much the temperature changes.

The Battery Temperature Sensor corrects the three charging set points noted aboveby the ollowing values (re erence temperature is 25 C / 75 F):

12 volt battery: 0.030 volts per C (0.017 volts per F) 24 volt battery: 0.060 volts per C (0.033 volts per F)

The temperature sensed by the BTS at the battery is displayed on the LCD screenunder the screen display Heatsink BTS (see Fig. 5.3). As the LCD display is notcapable o displaying negative values, battery temperature below 0 C will not bedisplayed. Voltage compensation will, however, be carried out below 0 C.


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Variations in battery temperature can a ect charging, battery capacity, and battery

li e. The greater the range o battery temperatures, the greater the impact on thebattery. For example, i the temperature alls to 10C (50F) this 15C (27F) change intemperature will change the PWM Absorption, equalization and oat set points by0.90V in a 24V system.

Typical compensation is given in Table 6.2 below:

Temperature 12 Volt 24 Volt50C / 122F 0.75 V 1.50 V

45C / 113F 0.60 V 1.20 V40C / 104F 0.45 V 0.90 V35C / 95F 0.30 V 0.60 V30C / 86F 0.15 V 0.30 V

25C / 77F (Re erence) 0 V (Re erence) 0 V (Re erence)

20C / 68F + 0.15 V + 0.30 V15C / 59F + 0.30 V + 0.60 V

10C / 50F + 0.45 V + 0.90 V5C / 41F + 0.60 V + 1.20 V0C / 32F + 0.75 V + 1.50 V

Table 6.2 Temperature Compensation


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7TROUBLESHOOTING

The SCC-30AB is very rugged and designed or the most extreme operating conditions.Most PV system problems will be caused by connections, voltage drops, and loads.Troubleshooting the SCC-30AB controller is simple. Some basic troubleshootingprocedures are listed below.

Protections & Fault Messages on the LCD Display

The LCD displays might have the ollowing ault messages when SCC-30AB stopsoperating due to protections/system error:

Display Description Cause o Fault

Alarm: OCOver Current Over Current The current exceeds 45 A

Alarm: OT Heat Sink over temperature Heat sink temperatureexceeds 90 C

Alarm: CPF00Link Master error Display Panel error

The CPU is not able toexchange data with the

Display Panel

SYMPTOM 1. BATTERY IS NOT CHARGING

Check the green LED indicator. The green CHARGING LED should be on i it isdaytime.

Check that the proper battery charging algorithm (program) has been selected byDIP Switches.

Check that all wire connections in the system are correct and tight. Check thepolarity (+ and ) o the connections.

Measure the PV array open-circuit voltage and confrm it is within normallimits. I the voltage is low or zero, check the connections at the PV array itsel .Disconnect the PV array rom the controller when working on the PV array.

Check that the load is not drawing more energy than the PV array can provide. Check i there are excessive voltage drops between the controller and the

battery. This will cause undercharging o the battery. Check the condition o the battery. Determine i the battery voltage declines

at night with no load. I it is unable to maintain its voltage, the battery may beailing.

Measure the PV voltage and the battery voltage at the SCC-30AB terminals. I the

voltage at the terminals is the same (within a ew tenths o volts) the PV array ischarging the battery. I the PV voltage is close to the open circuit voltage o thepanels and the battery voltage is low, the controller is not charging the batteriesand may be damaged.


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7TROUBLESHOOTING

SYMPTOM 2. BATTERY VOLTAGE IS TOO HIGH

First check the operating conditions to confrm that the voltage is higher thanspecifcations.

Check that the proper battery charging algorithm (program) has been selected byDIP Switches.

Check that all wire connections in the system are correct and tight. Disconnect the PV array and momentarily disconnect the lead rom the BATTERY

positive terminal BAT+. Reconnect the battery terminal and leave the PV arraydisconnected. The Green charging light should not be lit. Measure the voltageat the PV array terminals PV+ and PV- (with the array still disconnected). Ithe Green charging light is on or battery voltage is measured at the PV arrayterminals PV+ and PV- , the controller may be damaged.


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8SPECIFICATIONS

SYSTEMNominal system voltage 12 VDC or 24 VDC (Selected by DIP Switch)Current rating 30 ASet point accuracy + / - 50 mVMinimum voltage to start the micro-controller, activate protections and guideoperation

9 VDC

Total sel consumption current 50 mAINPUT SIDE (Solar panel / array)

Maximum open circuit voltage Voc o thesolar panel / array 50 VDC

Maximum operating voltage o the solarpanel / array 34 VDCMaximum short circuit current Isc o thesolar panel / array 30 A

BATTERY CHARGINGCharging algorithm PWM

Charging stages Bulk, Absorption, Float,Equalize (Selectable)

Battery Temperature Compensation With optional Battery Temperature Sensor(BTS) supplied with 10 t / 3 M o wireCoe fcient o temperature compensationwhen using optional Battery TemperatureSensor (BTS)

12 V: -5mV/ C / cell (25 C re erence)

24 V: -10mV/ C / cell (25 C re erence)Temperature compensation range 0 C to +50 C

PROTECTIONSHigh temp shutdown (Temp o the aceplate that is used as a heat sink)

90 C - disconnect solar panel / array70 C - re-connect solar panel / array

Over current (overload) shut down 45 ADISPLAY

Backlit LCD 2 lines X 16 characters, alpha numericLED 1 LED or status display

ENVIRONMENTAL

Ambient temperature -10 C to +45 CStorage temperature -55 C to +85 CHumidity 95% Non Condensing

MECHANICALDimensions (L X W X D) 7.48 X 4.25 X 1.38 inches / 190 X 108 X 35 mmWeight (With gi t box) 1.2 lbs / 0.55KgNet weight 0.8 lb / 0.36 KgEnclosure / ace plate Powder coated steel, or indoor use only

ACCESSORIES INCLUDEDInsulated spade lugs or input / output

connections

4 pieces

For # 8 stud; AWG 12-10 wire sizeSel tapping screws or fxing the aceplate

4 pieces7X19, 5/8; Type 25 point; Flat head; Philips

driveSpecifcations subject to change without notice


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9WARRANTY

5 YEAR Limited Warranty

SCC-30AB manu actured by Samlex America, Inc. (the Warrantor) is warranted tobe ree rom de ects in workmanship and materials under normal use and service.This warranty is in e ect or 5 years rom the date o purchase by the user (thePurchaser).

For a warranty claim, the Purchaser should contact the place o purchase to obtain aReturn Authorization Number.

The de ective part or unit should be returned at the Purchasers expense to theauthorized location. A written statement describing the nature o the de ect, thedate o purchase, the place o purchase, and the Purchasers name, address andtelephone number should also be included.

I upon the Warrantors examination, the de ect proves to be the result o de ectivematerial or workmanship, the equipment will be repaired or replaced at theWarrantors option without charge, and returned to the Purchaser at the Warrantorsexpense.

No re und o the purchase price will be granted to the Purchaser, unless the Warrantoris unable to remedy the de ect a ter having a reasonable number o opportunities todo so.

Warranty service shall be per ormed only by the Warrantor. Any attempt to remedythe de ect by anyone other than the Warrantor shall render this warranty void.

There shall be no warranty or de ects or damages caused by aulty installation orhook-up, abuse or misuse o the equipment including exposure to excessive heat, saltor resh water spray, or water immersion.

No other express warranty is hereby given and there are no warranties which extendbeyond those described herein. This warranty is expressly in lieu o any otherexpressed or implied warranties, including any implied warranty o merchantability,ftness or the ordinary purposes or which such goods are used, or ftness or aparticular purpose, or any other obligations on the part o the Warrantor or itsemployees and representatives.

There shall be no responsibility or liability whatsoever on the part o the Warrantor orits employees and representatives or injury to any persons, or damage to person orpersons, or damage to property, or loss o income or proft, or any other consequentialor resulting damage which may be claimed to have been incurred through the use or


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9WARRANTY

sale o the equipment, including any possible ailure o mal unction o the equipment,or part thereo .

The Warrantor assumes no liability or incidental or consequential damages o anykind.

Samlex America Inc. (the Warrantor)110-17 Fawcett Road

Coquitlam BC, V3K 6V2 Canada(604) 525-3836


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110-17 Fawcett RdCoquitlam, B.C.Canada V3K 6V2

T: 604 525 3836F: 604 525 5221

TF: 1 800 561 5885

e-mail: [email protected]: www.samlexamerica.com

Documents

SamlexsolarSCC 30AB Manual