Studer VS-70, VS-120 User Manual

VarioString

MPPT solar charge controller

User manual
VarioString	VarioString
VS - 120	VS -70
48V120A	48V70A

Accessories:

Remote control……………………………………. Temperature sensor…....…………………………. External auxiliary relay module...……………….

RCC-02/03 BTS-01 ARM-02

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Contents

1	INTRODUCTION ...................................................................................................................................			5
2	GENERAL INFORMATION ....................................................................................................................			5
	2.1	About this user manual.....................................................................................................................		5
	2.2	Important safety instructions............................................................................................................		6
	2.3	Conventions .......................................................................................................................................		6
	2.4	Quality and warranty........................................................................................................................		7
	2.4.1	Exclusion of warranty................................................................................................................		7
	2.4.2	Exclusion of liability....................................................................................................................		7
	2.5	Warnings and guidelines ..................................................................................................................		8
3	MOUNTING AND INSTALLATION.........................................................................................................			8
	3.1	Storage................................................................................................................................................		8
	3.2	Unpacking ..........................................................................................................................................		8
	3.3	Mounting place .................................................................................................................................		9
	3.4	Fixing/Dimensions ..............................................................................................................................		9
	3.4.1	VarioString VS-120 .....................................................................................................................		9
	3.4.2	VarioString VS-70 ....................................................................................................................		10
	3.4.3	Assembling the cooling fan ECF-01 .....................................................................................		10
4	WIRING ..............................................................................................................................................			11
	4.1	Elements of the cable compartment ..........................................................................................		11
	4.1.1	VarioString VS-70 .....................................................................................................................		12
	4.1.2	VarioString VS-120 ...................................................................................................................		13
	4.2	Connecting the battery .................................................................................................................		14
	4.2.1	Precautions when using the batteries .................................................................................		14
	4.2.2	Connecting the battery.........................................................................................................		15
	4.2.3	Protection device of the battery..........................................................................................		15
	4.3	Photovoltaic generator (PV) .........................................................................................................		16
	4.3.1	Dimensioning ...........................................................................................................................		16
	4.3.2	Serial connection (chain or string) of PV modules ............................................................		17
	4.3.3	Parallel connection of PV module strings ...........................................................................		18
	4.3.4	Safe use of the photovoltaic modules ................................................................................		19
	4.3.5	Protection devices..................................................................................................................		19
	4.3.6	Cable cross-section and connection..................................................................................		19
	4.3.7	Parallel connection of several VarioString ..........................................................................		19
	4.3.8	Extension of an existing installation ......................................................................................		20
	4.4	Earthing .............................................................................................................................................		20
	4.4.1	Detecting an earthing fault ..................................................................................................		20
	4.5	Lightning protection........................................................................................................................		21
	4.6	Connecting the communication cables.....................................................................................		21
5	POWER-UP OF THE EQUIPMENT ........................................................................................................			22
6	DISPLAY SYSTEM................................................................................................................................			23
	6.1	The “SET” button (4).........................................................................................................................		23
	6.2	“Night” standby indicator (1) ........................................................................................................		23
	6.3	“Charge” cycle indicator (2) ........................................................................................................		23
	6.4	“Error” indicator (3) .........................................................................................................................		24
	6.5	Charging current Indicator (5)-(6)-(7)-(8)-(9)-(10) ......................................................................		24
7	BATTERY CHARGING PROCESS ........................................................................................................			25
	7.1	General points .................................................................................................................................		25
	7.2	Battery cycle ....................................................................................................................................		25
	7.2.1	Bulk phase (1) ..........................................................................................................................		25
	7.2.2	Absorption phase (2)..............................................................................................................		25
	7.2.3	Floating phase (4) ...................................................................................................................		25
	7.2.4	Equalization phase (3)............................................................................................................		25
	7.2.5	Temperature compensation .................................................................................................		26
	7.3	Default battery charge cycle (original settings) ........................................................................		26
	7.4	Recovery after deep discharge ...................................................................................................		26
8	REMOTE ENTRY (AVAILABLE AS FROM SOFTWARE VERSION 1.5.22) ..............................................			27
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9	CONFIGURING THE VARIOSTRING(S)...............................................................................................			27
	9.1	Configuring the equipment by means of the internal DIP switches........................................		27
	9.2	Displaying the equipment status using the remote control RCC-02/03 .................................		29
	9.2.1		Displaying the status of a single unit system .......................................................................	29
	9.2.2		Displaying the operating mode of the equipment (Info n° 15013,15014,15015) ..........	31
	9.2.3		Displaying security errors (Info n° 15049) .............................................................................	32
	9.2.4		Displaying the values of a multi-unit system .......................................................................	32
	9.2.5		Displaying messages and event history ..............................................................................	32
	9.3	Configuring the VarioString using the remote control RCC-02/03 ..........................................		33
	9.3.1		The real time clock .................................................................................................................	33
	9.4	Description of the VarioString parameters ..................................................................................		33
	9.4.1		Convention ..............................................................................................................................	33
	9.4.2		Parameter access level .........................................................................................................	34
	9.4.3		Organisation of the VarioString configuration menu ........................................................	34
	9.4.4		Basic settings {14000}..............................................................................................................	36
	9.4.5		Battery management and cycle {14003} ...........................................................................	36
	9.4.6		System {14037} .........................................................................................................................	40
	9.4.7		Auxiliary contacts 1 {14070} and 2 {14122} .........................................................................	42
10	ACCESSORIES ...................................................................................................................................			46
	10.1	Remote control and programming centre RCC-02/03.............................................................		46
	10.2	Temperature sensor BTS-01.............................................................................................................		47
	10.2.1		Connecting the temperature sensor (BTS-01) ....................................................................	47
	10.3	Auxiliary relay module ARM-02......................................................................................................		48
	10.4	Parallel connection cable .............................................................................................................		48
11	EQUIPMENTS COMPATIBLE WITH THE VARIOSTRING .......................................................................			48
	11.1	Xtender inverter/chargers..............................................................................................................		48
	11.2	Battery status processor BSP500/1200 ........................................................................................		48
	11.3	Communication module Xcom-232i............................................................................................		49
	11.4	Communication sets Xcom-LAN/-GSM........................................................................................		49
	11.5	Communication module Xcom-SMS............................................................................................		49
	11.6	Multi-protocol communication module Xcom-CAN .................................................................		49
12	WIRING EXAMPLES............................................................................................................................			50
	12.1	VarioString + RCC-02.......................................................................................................................		50
	12.2	Comments on the wiring examples 12.1 .....................................................................................		50
	12.3	VarioString VS-70 + RCC-02............................................................................................................		51
	12.4	Comments on the wiring examples 11.3 .....................................................................................		51
13	MAINTENANCE OF THE INSTALLATION.............................................................................................			52
14	PRODUCT RECYCLING ......................................................................................................................			52
15	EU DECLARATION OF CONFORMITY ................................................................................................			52
16	TROUBLE-SHOOTING.........................................................................................................................			53
17	PARAMETER LIST ................................................................................................................................			54
18	TECHNICAL DATA..............................................................................................................................			58
	18.1	General specifications....................................................................................................................		58
	18.2	Input (PV generator) .......................................................................................................................		58
	18.3	Output (battery) ..............................................................................................................................		58
	18.4	Environment......................................................................................................................................		59
	18.5	Protection .........................................................................................................................................		59
	18.6	Communication ..............................................................................................................................		59
	18.7	Compliance .....................................................................................................................................		59
19	INDEX OF PARAMETERS ....................................................................................................................			60

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1 INTRODUCTION

Congratulations! You are about to install and use a device from the VarioString range. You have chosen high-tech equipment that will play a central role in the energy production of your solar electrical installation. The VarioString has been designed to work as a solar battery charger; its advanced and completely configurable functionalities will guarantee a perfect functioning of your energy system.

When the VarioString is connected to batteries and photovoltaic panels, it automatically recharges batteries in an optimum way with all the available solar power. The VarioString VS-120 can be connected to two strings of PV modules in different configurations (series, parallel, or independent). This configuration flexibility allows the user to optimise their installation. The accuracy of the Maximum Power Point Tracking (MPPT) algorithm, the high output and low internal consumption ensure an optimal valorisation of the energy produced by the PV modules.

The charge profile may be set freely according to the battery type or the operation mode. The charging voltage is corrected depending on the temperature thanks to the optional external sensor BTS-01.

The control, display and programming unit RCC-02/03 (optional) allows an optimal setup of the system and guarantees the user a permanent control over all important parameters for the installation with a clear display interface. Moreover, it allows recording the system data in order to analyse later its functioning (data logging).

The parallel operation of several chargers is possible and offers modularity and flexibility enabling an optimum dimensioning of your system according to your energy requirements.

The VarioString operates as an independent device but is also designed to be included into a Studer energy system together with the Xtender inverters/chargers, the BSP battery monitor, the control, display and programming unit RCC-02/03 and all Xcom communication modules. Working together, these different devices have a synchronised behaviour for a better management of the battery and of the solar resource.

Please read this manual carefully to ensure the perfect start up and operation of your system. It contains all necessary information regarding the operation of the VarioString charger. The installation of such a system requires special expertise and may only be carried out by qualified personnel familiar with the local standards in force.

2 GENERAL INFORMATION

2.1ABOUT THIS USER MANUAL

This manual contains necessary information and procedures to install, configure, use and troubleshoot the VarioString solar charge controllers. It does not contain information about photovoltaic modules (PV) or batteries of various brands that can be connected. For this kind of information, please refer to the instructions of each specific manufacturer.

It covers the following models and accessories:

MPPT solar charge controller: VarioString VS-70, VarioString VS-120

Temperature sensor: BTS-01

External auxiliary relay module: ARM-02

This manual is an integral part of the equipment and must be available for the operator and/or the installer at all times. Always keep it close to the installation.

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2.2IMPORTANT SAFETY INSTRUCTIONS

This manual contains important safety instructions. Read carefully the safety and operation instructions before using the VarioString. Take into consideration all warnings mentioned both on the equipment and in this manual, strictly following all instructions regarding its operation and use.

This user manual is intended to serve as a guideline for the safe and efficient use of the VarioString. Anyone who installs or uses a VarioString can completely rely on this user manual and is bound to observe all the safety instructions and indications here in.

The installation and commissioning of the VarioString must be entrusted to qualified personnel. The installation and use must comply with the local safety instructions and standards in force in the country.

2.3CONVENTIONS

This symbol is used to indicate safety instructions which, if not followed, could result in serious personal injury or death to the operator or the user.

This symbol is used to indicate a general danger for the user and/or a risk of material damage and/or the cancellation of the guarantee.

This symbol is used to indicate a procedure or function that is important for a safe and correct use of the equipment. Failure to respect these instructions may lead to the cancellation of the guarantee or to a non-compliant installation.

This symbol placed on the product indicates that its surfaces may reach temperatures higher than 60°C.

This symbol placed on the product indicates that its use must follow the instructions in the user’s manual.

In general, values important for the operation of the equipment (for example: battery voltage during absorption) are not mentioned and the parameter number is indicated in the following format: {xxxxx}. The value of the parameter can be found in the table chap. 16.

In most cases, these values can be modified with the remote control RCC-02/03 (see chap. 10.1).

The parameter table available at the end of this manual (chapter 16) must be kept updated in case the parameters are modified by the operator or the installer.

If an authorised person modifies a parameter not included in the list (advanced parameters), the number of the modified parameter(s), the specifications of the parameter(s) and the new value set are to be indicated at the end of the table.

All values that are not followed by a parameter number may not be modified.

All digits and letters in brackets or in square brackets in the text of this manual refer to items represented in illustrations with a circle.

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2.4QUALITY AND WARRANTY

During production and assembly of the VarioString, each unit undergoes several checks and tests which strictly comply with established procedures. The manufacturing, assembling and testing of each VarioString are completely carried out in our factory in Sion (CH). The equipment warranty depends upon the strict application of the instructions in this manual.

The VarioString MPPT solar charge controller has a 5-year warranty (starting from the date of production against material and manufacturing faults). A defective product will either be repaired or replaced at the discretion of Studer Innotec.

2.4.1 Exclusion of warranty

No warranty claims will be accepted for damages resulting from handling, use or treatment that are not explicitly mentioned in this manual. In particular, damages arising from the following causes are excluded from the warranty:

Voltage higher than 600V across PV terminals (independent or parallel configuration) or higher than 900V (series configuration).

Accidental presence of liquids in the equipment or oxidation due to condensation.

Damage resulting from falls, mechanical shocks or permanent or excessive vibrations.

Modifications carried out without the explicit authorisation of Studer Innotec.

Nuts or screws that have not been tightened sufficiently during the installation or maintenance.

Damage due to atmospheric surge voltage (lightning).

Damage due to inappropriate transportation or packaging.

Disappearance of original identification marks.

Never take off or damage the rating plate showing the serial number. It enables to check and follow-up the data specific to each equipment and is vital for any warranty claim.

2.4.2 Exclusion of liability

The installation, commissioning, use, maintenance and servicing of the VarioString cannot be subject of monitoring by Studer Innotec. Therefore, we disclaim all responsibility and liability for damage, costs or losses resulting from an installation that does not comply with the instructions, a faulty operation or inadequate maintenance. The use of Studer Innotec equipment is in any case under the responsibility of the customer.

This equipment is neither designed nor guaranteed to supply installations used for vital medical care nor any other critical installation entailing potential risks of important damage to people or to the environment.

We assume no responsibility for the infringement of patent rights or other third parties rights resulting from the use of the MPPT solar charge controller VarioString.

Studer Innotec reserves the right to make any modifications to the product without prior notification.

Studer Innotec is not liable for incidental, direct or indirect damages of any kind, including any profit loss, revenue loss or damages caused to equipment or goods due to defective equipment.

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2.5WARNINGS AND GUIDELINES

The installation and commissioning of the VarioString must be entrusted to skilled and qualified personnel perfectly aware of the safety precautions and local rules in force. All elements connected to the VarioString must comply with the laws and regulations in force.

HIGH-VOLTAGE DC INSIDE THE CHARGE REGULATOR: DANGER OF DEATH

When the VarioString is in operation it generates voltages that can be potentially lethal (up to 600V (VS-70) and 900V (VS-120)). Any work on or close to the installation must only be carried out by thoroughly trained and qualified personnel. Do not try to carry out ordinary maintenance on this product yourself.

While working on the electrical installation, it is important to make sure that the source of DC voltage coming from the battery as well as the source of DC voltage coming from the photovoltaic generator, have been disconnected from the electrical installation.

Even when the VarioString has been disconnected from the power sources, a potentially dangerous voltage may remain at the terminals. To eliminate this you have to wait for at least 5 minutes in order to allow the electronics to discharge. The task can then be carried out safely.

No person is authorized to proceed with any change, modification or repair of the equipment without prior written authorisation from Studer Innotec. Only original parts should be used in authorised modifications or replacements.

Respect the maximum rated specifications of the equipment indicated on the type label.

The VarioString can be installed at altitudes up to 3000m. For installations at higher altitudes, please contact Studer Innotec SA.

The VarioString is in overvoltage category II, in accordance with the norm IEC/EN 62109- 1:2010 that considers all solar generators as being in overvoltage category II.

3 MOUNTING AND INSTALLATION

The wiring and connection of the installation must be carried out only by perfectly qualified personnel. The installation material such as cables, connectors, distribution boxes, fuses, etc., must be appropriate and comply with the laws and regulations in force for the application in question.

3.1STORAGE

The equipment must be stored in a dry environment at an ambient temperature between -20°C and 60°C. Place the equipment at its mounting place at least 24 hours before commissioning in order to avoid thermal shocks and condensation problems.

3.2UNPACKING

When unpacking, check that the VarioString has not been damaged during transportation and that all accessories listed below are present. Any fault must be immediately reported to the product distributor or the contact mentioned at the back of this manual.

Carefully check the packaging as well as the VarioString. Contents in the VarioString box:

VarioString

Installation and operation manual

Cable-glands for the battery cables

Solar cable connectors, 1 pair (VS-70) and 2 pairs (VS-120)

Communication cable

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3.3MOUNTING PLACE

The mounting place for the VarioString is particularly important and must fulfil the following criteria:

Indoors

Protected from water and dust in a location without condensation.

Protected from any unauthorized person.

In a place where the relative humidity does not exceed 95%

In a place where the ambient temperature is between -20 and 55°C

In mobile applications, it is important to select a mounting place that ensures no vibration.

Protected from direct solar radiation or heat sources.

It should not be mounted directly above the battery or in a cabinet with the battery

The ventilation vents should be clear at all times and at least 20 cm from all obstacles that could alter the ventilation of the device.

Given the norm IEC/EN 62109-1, the degree of pollution in the installation area should be at maximum PD2 for the VS-120 and PD3 for the VS-70.

The support for the VarioString and the environment in which it is contained should not be flammable.

The presence of a heat source may significantly reduce its rated power. Similarly, insufficient ventilation may lead to the overheating of some internal components of the equipment. In this case, the device will automatically limit its power as long as this abnormal situation persists.

As far as possible, reduce exposure to sudden temperature variation: important heat variation may create undesired and harmful condensation inside the equipment.

3.4FIXING/DIMENSIONS

The VarioString is a heavy equipment (5.5 kg (VS-70) and 7.5 kg (VS-120)) and must be mounted to a support (wall) designed to bear such a load. It is imperative to ensure a complete and safe fastening of the equipment. If simply hung, it may fall down and cause severe damages.

The VarioString must be installed vertically. A distance of at least 5cm between the units and/or 20cm around the equipment is required to guarantee adequate ventilation.

If the VarioString is installed in a closed cabinet, it must have sufficient ventilation to guarantee that the ambient temperature is kept within the operating limits of the VarioString.

In motor vehicles, or when the support undergoes significant vibrations, the VarioString is to be mounted on anti-vibration elements.

3.4.1 VarioString VS-120

Upper support screw: screw into the wall a 6-8 mm diameter screw without washer until there is 1.6 mm between the head of the screw and the wall. Hang the device from the screw. If deemed

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necessary, the upper support screw can be fully tightened after hanging the device. In theory this is only necessary in mobile applications. To access the upper support screw to fully tighten it, remove the upper plastic grate.

Lower support screws: remove the lower plastic grate which gives access to the cabling compartment. Carefully fix the device to the support with two screws (6-8 mm in diameter) using the two mounting holes located at the bottom left and right of the cabling compartment.

3.4.2VarioString VS-70

The VS-70 enclosure is fitted with a support plate to be mounted on the back of the case using 4 screws M6, 8 mm long, and washers (see fig. hereafter), before wall mounting. Mount it vertically with the cable-glands downward.

The external cooling fan can be installed before or after the equipment has been mounted on the wall.

The 4 mounting screws of the enclosure must be completely tightened with a torque of (>3Nm - 10Nm<) in order to guarantee the IP 54 protection index. Any unused cable glands should be closed in a way that guarantees at least the same level of protection.

3.4.3 Assembling the cooling fan ECF-01

The VarioString VS-70 is supplied with an external cooling fan module (ECF-01). This module can be installed before or after mounting the VarioString VS-70, on the wall.

This fan has a degree of protection IP54 and can be exposed to water spray without damage. However, do not expose it to dirty water splashes in order to prevent mud or similar particles from blocking the mechanism.

Assembly instructions:

1.Remove the plastic cap and insert the connector until the click sound.

2.Position the cover by inserting the screws.

3.Fully tighten the two screws.

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4 WIRING

The connection of the VarioString charger is an important step of the installation.

It may only be carried out by qualified personnel, aware of the rules and regulations in force. The installation must always comply with these standards. The cross-sections of the cables connected to its terminals must comply with local regulations. All cables in use should be isolated with PVC, TFE, PTFE, FEP, neoprene or polyimide.

Make sure that connections are completely tightened and that each wire is connected at the right place.

The VarioString is intended to be connected exclusively to a source like a photovoltaic generator, excluding any other energy source.

It is suitable for charging any type of lead-acid batteries. It is often possible to charge any other type of battery using proper settings and with the express approval of the battery supplier.

The connection compartment of the VarioString must remain permanently closed while the apparatus is operating.

Before opening, check that all voltage sources (battery and PV) have been disconnected or switched off and wait for at least 5 minutes before opening the equipment. It is imperative to close the protection cover on the connection terminals after each servicing.

4.1ELEMENTS OF THE CABLE COMPARTMENT

	No.	Description					Comments
		Terminal to connect the battery positive					This connection must be done using a protection
		pole
							and disconnection device if the pole has not
	1	VS-70: M6, 5Nm torque, PG-16 (10-14mm)
							been earthed. For mounting of the internal fuse,
		VS-120:	M10,	8Nm	torque,	PG-21
							refer to sect. 4.2.2
		(13-18mm)
		Terminal to connect the battery
		negative pole					This connection must be done using a protection
	2	VS-70: M6, 5Nm torque, PG-16 (10-14mm)					and disconnection device if the pole has not
		VS-120:	M8,	8Nm	torque,	PG-21	been earthed.
		(13-18mm)
	3	Connector (Sunclix) for negative pole of
		solar generator.
	4	Connector (Sunclix) for positive pole of					The solar generator wiring must be carried out in
		solar generator.
							compliance with the voltage and current limits
		Connector (Sunclix) for negative pole of
	5						mentioned on the rating plate.
		solar generator. (VS-120 only)
	6	Connector (Sunclix) for positive pole of
		solar generator. (VS-120 only)
		Socket for connection of accessories BTS-					Only the mentioned original accessories can be
	7	01 or	ARM-02	(battery temperature
							connected to this connector.
		sensor and auxiliary relay module)
		Socket for communication cables and					RJ45 connector used for connecting equipment
	8						of the Xtender family. These connections must be
		the remote control RCC-02/03.
							carried out only with original Studer cables.
	9	Termination switch					The switch must be placed in position O (towards
							(8)) when both connectors are used.
	10	Configuration switches (DIP switch)					The various possible configurations are described
							in sect. 9.1
	11	Real-time clock battery					The equipment is fitted with a battery lasting
		(type CR 2032)					about 10 years.

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	No.	Description	Comments
			Available as from software version 1.5.22. Allows
			the control of a function – to be defined by
	12	Remote entry	programming – by the closing of a dry contact or
			by the presence of a voltage across these
			terminals.
	13	Jumper for programming of the remote	See sect. 8 – p. 27 in fig. 4.1.1 and 4.1.2. By default,
		entry	they are positioned at A-1/2 and B-2/3.
	14	Battery protection fuse	VS-70 : Fuse 100A/80V (sect. 4.2.2.2)
			VS-120 : Fuse CF8/150A/58V (sect. 4.2.2.1)
	4.1.1	VarioString VS-70

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4.1.2 VarioString VS-120

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4.2CONNECTING THE BATTERY

The VarioString is a device which DC (battery) connection is to be connected exclusively to a battery. Most of the time, lead-acid batteries with liquid (VLA, VRLA) or gelled (GEL) and AGM electrolyte may be used. It can be easily configured to create charge profiles that are compatible with these various types of lead-acid batteries.

In any case, the max charge current should be within the limit established by battery manufacturer. If necessary, the charge current can be limited with the aid of parameter {14001}.

Using the VarioString connected to any other type of DC source without battery is strictly forbidden and may cause significant damage to the equipment and / or to the source.

The use of other battery types like Ni-Cd, Li-ion or other is possible if the charge profile is properly programmed, in accordance with the specifications of the battery manufacturer, in agreement with the battery manufacturer and under the responsibility of the installer.

4.2.1Precautions when using the batteries

The batteries should only be chosen, dimensioned and installed by qualified personnel, trained in this specific area. When working with batteries, a second person is required in order to give assistance in case of problems.

Lead-acid batteries with liquid or gelled electrolyte produce a highly explosive gas during normal use. Avoid any source of sparks or fire in the immediate vicinity of the batteries. The batteries must be kept in a well-ventilated place and installed so as to avoid accidental short-circuits when connecting.

Never try to charge frozen batteries.

It is advised to never work alone with batteries. The presence of a second person is necessary to provide assistance in the event of a problem.

Sufficient fresh water and soap must be kept close at hand to allow adequate and immediate washing of the skin or eyes affected by accidental contact with the battery acid.

In the event of accidental contact of the eyes with acid, they must be washed carefully with cold water for 15 minutes. Then immediately consult a doctor.

The battery acid can be neutralized with baking soda, among other things. A sufficient quantity of baking soda should be available for this purpose.

Particular care is required when working close to batteries with metal tools. Tools such as screwdrivers, open-ended spanners, etc., may cause short circuits. Sparks created by short-circuits may cause the battery to explode. Therefore these kinds of tools must always have isolated handles and never be placed on top of a battery.

When working with batteries, all metal jewellery such as rings, watches with a metal bracelet, earrings, etc., must be taken off. The current supplied by the batteries during a short circuit is sufficiently powerful to melt the metal and cause severe burns.

Batteries at the end of their life-cycle should be recycled in accordance with directives from the responsible local authorities or the battery supplier. The batteries should never be thrown into fire as they may explode. Under no circumstances should you try to take apart or dismount the battery, as they contain toxic and polluting materials.

For ungrounded battery systems, always check that they are not inadvertently grounded before starting working on the batteries.

Always follow carefully the instructions of the battery manufacturer.

If the battery voltage exceeds 68V, the charger turns off and starts again when the voltage is lower than 64V.

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A battery voltage higher than 75V can cause important damage or destroy the equipment. Such a voltage applied on equipment connected downstream like Xtender inverters/chargers or other, can cause important damage or destroy the equipment!

4.2.2 Connecting the battery

All connection cables as well as the battery cables must be mounted using cable restraints in order to avoid any pulling on the connection.

Battery cables must be as short as possible and the cross-section must comply with the regulations and standards in force. Tighten the clamps on the “Battery” inputs sufficiently.

Each VarioString is connected directly to the battery using its own protective device. All other consumers or sources are connected directly to the battery through their own protective device.

Lead batteries are usually available in 2V, 6V or 12V blocks. In most cases, in order to get the correct operating voltage for the VarioString, several batteries must be connected in series. The capacity of the batteries can be increased using a parallel connection of several battery strings.

Some battery manufacturers limit the use or advice against parallel connection of battery strings. Strictly conform to the manufacturer's instructions of use.

In multi-unit systems (connected to the same communication bus), all VarioStrings must be connected to the same battery bank.

4.2.2.1VarioString VS-120

a = M10 cable lug!! b = bolt M8x30

c = washer

d = ceramic washer

e = fuse CF8 (58V, 150A)

4.2.2.2VarioString VS-70

See illustration on page 12, number (1) and (2). M6 cable lug.

4.2.3 Protection device of the battery

The battery cables must be as short as possible. The recommended cable cross-section is 25mm2 for VS-70 and 50mm2 for VS-120. The protection devices (battery side) must be 80A for VS-70 and 125A for VS-120. The protection device must be installed as close as possible to the battery. The recommended cross-section of battery cable is valid for lengths up to 3m. Beyond this length, it is recommended to oversize the section of the battery cables.

Any other sources or loads existing on the battery must be connected using their own protection devices. Never connect them to the protection device(s) of the VarioString.

An annual check of all the connection tightness is recommended. In mobile installations, the connection tightness should be checked more often.

Battery cables must always be protected by a protection and disconnection device (fuse, circuit breaker) on the pole not connected to earth.

The protection device must be rated according to the cable cross-section but must not exceed 1.25 x VarioString maximum current. It will be mounted as close as possible to the battery.

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4.3PHOTOVOLTAIC GENERATOR (PV)

The VarioString may accept the following maximum input voltages:

VS-120		600	V max for independent and parallel cabling
		900	V max for series cabling
VS-70		600V

The whole solar system must be installed according to protection class II.

The capacitor banks inside the VS-120 hold a DC voltage for several minutes after the PV input is disconnected. It is necessary to wait 10 minutes before reconnecting the PV input cables after making any changes to the PV array or its wiring.

When connecting the PV inputs in parallel, it is necessary to first connect the VarioString MPPT channel inputs in parallel, and then connect the PV array positive and negative cables to the paralleled VarioString positive and negative inputs.

4.3.1 Dimensioning

The solar generator is dimensioned to cover an important part or the entire power requirement of the system. Once the power has been decided upon, it will be distributed among one or more solar charge regulators, wisely combining the modules among them. These combinations in series and in parallel must be carried out according to the voltage and current limits of the VarioString solar charge controller.

The possible operating range of the VS-70 is illustrated in the graph below:

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The VS-120 possible operating range within different configurations are indicated in the graph below (blue (A): one independent input, red (B): two inputs in parallel, green (C): two inputs in series).

4.3.2 Serial connection (chain or string) of PV modules

To get the optimum voltage, connect the PV modules in series to form a string with the desired voltage.

When using the two entries of the VarioString VS-120 in series, the + terminal of the PV1 entry (6) should be connected to the + pole of the PV generator. The – terminal of the PV2 entry (3) should be connected to the – pole of the PV generator and a bridge should be made between the entries (4) and (5).

The open-circuit voltage of the string must be lower than 600V under any temperature and irradiation conditions. A 10 to 20% margin is recommended in order to cover these unknowns. When the two inputs are used in series on the VarioString VS-120, the maximum open-circuit voltage should not surpass 900V.

To establish the maximum numbers of the PV modules connected in series in the same string, use the following formula: 600V/(Uoc*1.1). (Example: 600/(22*1.1)=24.79). The result must be rounded down (i.e. 24 modules - of 22 Voc - in series for the above example).

The table below gives an idea of the possible arrangements for common PV modules according to the number of cells or their type:

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36 cell

60 cell

72 cell

Thin film

module

module

module

module

Voc < 25V

Voc < 42V

Voc < 50V

Voc < 110V

max.

max.

max.

--

21

12

10

4

For VS-70 or VS-120 with

independent or parallel inputs

32

19

16

7

For VS-120 with two inputs in series

Beware of the PV module temperature! The above values are for modules under standard test condition (STC).

4.3.3 Parallel connection of PV module strings

To get the required charging power, 2 or more strings can be connected in parallel. Each string connected in parallel shall be composed of the same number of modules of the same type.

When using the two entries on the VarioString VS-120 in parallel (up to 26A) it is necessary to physically connect the two negative terminals (3) and (5) as well as the two positive terminals (4) and (6).

The two inputs can only be put in parallel when there is no voltage present. The four inputs (3), (4), (5) and (6) should be disconnected at least 10 minutes before connecting the "Y" cable in parallel.

1.Disconnect all PV sources and wait 10 minutes.

2.First connect the inputs (3) and (5), and (4) and (6) with the "Y" parallel cable.

3.Only at this point, the PV generators may be connected to the "Y" cables.

The number of strings connected in parallel depends on the power of each module. The sum of the power of all the panels connected to a VarioString should not exceed the power that the VarioString can charge.

The recommended number of strings to be connected in parallel is equal to 3500W divided by the power of a string and rounded down to the nearest whole number. (see table below)

For example, with 12 modules of 110W in series: 3500/1320=2.65 => 2 strings (2640W) can be connected in parallel.

If both VarioString inputs are connected in parallel, for the
		Maximum recommended power
strings of 12 modules in series mentioned above, 5 strings
		for the solar generator
could be connected in parallel (7000/1320=5.3 =>5).
		VS-120			Battery
The PV generator can be over-dimensioned in order to get		MPPT input 1		3500W	48V
the required charging power even when solar irradiation is		MPPT input 2		3500W	48V
lower. In this case, a part of the solar energy will be lost		Total		7000W	48V
when the solar irradiation is higher because the VarioString

will reach its current limit and curtail power output. By looking at the example above, 3 strings could be used however the maximum power of 3960W will not be reached as the VarioString will limit the power to a maximum value of 3500W.

The VarioString has a current limit. At any given time, the maximum power of the VarioString depends on the charging phase voltage of the battery. For example, if the charging phase is Bulk, and the battery voltage is 50V, the maximum power output for the VS-120 is 120A * 50V = 6000W and for the VS-70 70A*50V = 3500W. Even if more solar energy is available, the battery charge current will not exceed 120A (VS-120) and 70A (VS-70).

4.3.3.1Maximum current of the solar generator

The maximum current of the solar generator is limited to 13 A for the VS-70 and the VS-120 when connected in series or independently (13A per input) or to 26A for the VS-120 when connected in parallel.

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In any case, the VarioString will limit the charging current (battery) to its rated current of 120A for the VS-120 or 70A for the VS-70.

4.3.4 Safe use of the photovoltaic modules

The VarioString is meant for PV generators supplying up to 600V (900V in series). This voltage is dangerous for human beings.

During the installation or the maintenance of the system, it is imperative to make sure that no dangerous voltage may surge in the system. The disconnection device must be open and secured against any accidental reclosing.

4.3.5 Protection devices

Wiring protection devices (fuses, circuit breakers) connecting the PV generator to the VarioString must be installed in accordance with local standards and regulations in force.

The DIN VDE 0100-712 standard prescribes a switching device on all poles between the PV generator and the charge regulator. This device must be supplied by the installer.

PV modules are often exposed to stormy weather. It is highly recommended to install lightning protection (see chap. 4.5).

4.3.6 Cable cross-section and connection

The connection cable cross-section must be chosen according to the short-circuit current of the PV generator and the local installation rules. PV connectors of Sunclix type do not need any special tools for mounting. They accept cables between 2.5 and 6mm2 (exterior of 5 to 8mm2). Strip the cable 15mm to attach the Sunclix connector.

4.3.7 Parallel connection of several VarioString

As many VarioStrings as necessary can be connected in parallel on the same battery bank according to the battery capacity. Each will have its own independent solar generator (connected in independent, parallel or series configuration) and include its own disconnection and protection device to the battery.

Under no circumstances should PV module inputs of several VarioString be put in parallel.

Up to 15 VarioStrings can be synchronized and interconnected to the same communication bus (see chap. 4.6) on a single system. Beyond these 15 units, any additional unit will not be interconnected and thus their battery cycles will work independently.

Solar generators may be of various types and be orientated differently. Each VarioString will adjust the optimum point of the PV generator independently of the other units connected to the same battery.

In multi-unit systems (connected to the same communication bus), all VarioStrings must be connected to the same battery bank.

When the VarioString units are not synchronized, they must be programmed in the same way and it is recommended to not activate the periodical equalization function. The equalization can be started manually or will be done by the synchronized units.

For multi-unit systems, the devices are connected to each other by a communication bus (see chap. 4.6) via the connectors (8) and a cable (ref. CAB-RJ45-8-2) with a maximum length of 5 meters.

As long as they are correctly connected together by the communication cable, the VarioString automatically synchronize the battery charge cycle.

When the devices are in the voltage regulation phase, their respective currents may considerably differ. These differences have no effect at all on the charge quality.

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If a VarioString is connected to another compatible device (Xtender, VarioTrack, VarioString, BSP, RCC, Xcom) with the same communication bus, it is highly recommended to make a software update of all components in the system in order to guarantee all functionalities.

During the commissioning of the equipment in a multi-unit configuration, the system checks automatically the compatibility of the software versions and may prevent the operation in case of incompatibility. An upgrade of the installation must then be carried out by means of the RCC-02/03 remote control using the latest manufacturer's software version (read the user manual for the control and monitoring unit RCC-02/03 to carry out this operation).

4.3.8 Extension of an existing installation

In interconnected installations, if the software is compatible, it is possible to extend an existing installation by adding one or several (up to 15) VarioString units in parallel.

4.4EARTHING

The VarioString is a Class I protection equipment, its metal case must be earthed by means of the grounding screw, included for that purpose.

= protective earth (connected to the enclosure of the equipment).

The solar generator (as well as its wiring) must be Class II isolated.

The cross-section of the earthed cable must not be less than 16mm2.

The whole solar system must be installed according to protection class II.

In any case, the protective earth must be connected in accordance with local standards and regulations in force. The protective earth of the equipment must at least be connected to the earthed ground of all the Class I equipment after and before the VarioString (equipotential connection). The information, notes, recommendations and diagrams reported in this manual are subject to local installation rules. The installer is responsible for the conformity of the installation with the local standards in force.

4.4.1 Detecting an earthing fault

The choice of earthing system for the DC circuit is an important factor for the individuals' safety. Once the decision is made the VarioString can check the continuity of the earth connection.

In case of failure of this connection, the LED (3) (see sect. 6) lights up indicating the fault. A permanent message (requiring a validation) is displayed on the RCC if present.

The parameters {14040}, {14041} and {14042} allow establishing the type of control to be carried out or the absence of control as set by default.

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