FRO­NIUS 125/25 User manual

Operating Instructions
/ Battery Charging Systems / Welding Technology / Solar Electronics
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Fronius String Control 125/25
42,0410,1572 003-13122012

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EN-US
Dear Fronius Customer,
Thank you for choosing Fronius - and congratulations on your new, high-quality, high-
tech Fronius product. This introduction should provide you with general information
about the equipment. Please read it carefully to learn about the many great features of
your new Fronius product. This is the best way to get the most out of all the advantages
that it has to offer.
Please also note the safety information and the safety precautions for the product
installation location. Following all product instructions will ensure long-lasting quality and
reliability. And these are the essential ingredients for outstanding results.
Introduction

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I
EN-US
Safety Instructions
This equipment has been manufactured using state-of-the-art technology
and in accordance with general safety regulations. However, incorrect
operation or misuse may endanger:
- the life and well-being of the operator or third parties
- the equipment and other property of the owner/operator
- the efficient operation of the equipment.
All persons involved with equipment startup, service and maintenance must:
- be suitably qualified
- be familiar with electrical installations
- have completely read and followed these operating instructions
The operating instructions must be available at the equipment location at all
times. In addition to the operating instructions, all applicable local rules and
regulations regarding accident prevention and environmental protection must
also be followed.
All safety instructions and warning signs on the equipment itself:
- must be maintained in legible condition
- must not be damaged
- must not be removed
- must not be covered or painted over
For information about where the safety instructions and warning signs are
located on the equipment, please refer to the “General“ section of your
equipment’s operating instructions.
Any equipment malfunctions which might impair safety must be remedied
immediately before the device is turned on.
Your safety is at stake.
General
NOTE! Indicates a situation which could adversely affect work results and may
cause damage to equipment.
„DANGER!“ Indicates an immediate danger. Death or serious injury may
result if appropriate precautions are not taken.
„WARNING!“ indicates a potentially dangerous situation. Death or serious
injury may result if appropriate precautions are not taken.
„CAUTION!“ Indicates a situation where damage or injury could occur. Minor
injury or damage to property may result if appropriate precautions are not
taken.
„Important“ Highlights tips for correct operation and other particularly useful
information. It does not indicate a potentially damaging or dangerous situation.
If you see any of the symbols depicted in the „Safety Rules,“ special care is required.
Explanation of
Safety Warnings!

ud_fr_se_sv_01381 012012 II
Maintenance and repair may only be carried out by an authorized specialist.
The use of third-party parts does not guarantee that they were designed and
manufactured according to operational demands and safety requirements.
Use only original spare parts (also applies to standard parts).
Do not carry out any alterations, installations or modifications to the device
without first obtaining the manufacturer’s permission.
Immediately replace any components that are not in perfect condition.
Safety Precauti-
ons at Equipment
Location
When installing devices with air vents, make sure that cool air can flow freely through the
vents unobstructed. The device should only be operated in accordance with the protec-
tion class listed on the rating plate.
The equipment may only be operated in compliance with its intended use.
Any other purpose does not constitute intended use. The manufacturer is not
responsible for any damages resulting from unintended use.
Intended use also includes:
- reading and complying with all general information as well as safety
information and warnings from the operating instructions
- compliance with all inspection and maintenance requirements
- installation as per operating instructions
Where appropriate, the following guidelines should also be applied:
- Utility company regulations regarding grid feed-in
- Information from solar module manufacturer
Intended Use
Operation and/or storage of the device outside of the stipulated range does
not constitute intended use. The manufacturer is not responsible for any
damages resulting from unintended use.
Please refer to the technical data in your operating instructions for informati-
on about permitted ambient conditions.
Ambient Conditi-
ons
Qualified Person-
nel
The servicing information contained in these operating instructions is intended
only for the use of qualified service engineers. An electric shock can be fatal.
Please do not perform any actions other than those described in the docu-
mentation. This also applies to qualified personnel.
All cables and wires must be secured, undamaged, insulated and adequately
dimensioned. Loose connections, scorched, damaged or under-dimensioned
cables and wires must be repaired immediately by an authorized specialist.

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III
EN-US
EMC Precautions In special cases, there may still be interference for the specified application
area despite maintaining standardized emission limit values (e.g. when
sensitive equipment is located at the setup location or when the setup
location is near radio or television receivers).
In this case, the operator is obliged to take proper action to rectify the
situation.
Grid connection Devices with a high output (> 16 A) can influence the voltage quality of the
grid due to a high current input into the main supply.
This can affect several device types in the form of:
- Connection limitations
- Requirements regarding permitted mains impedance *)
- Requirements regarding minimum required short circuit power *)
*) for each interface to the public grid
See technical data
In this case, the operator or the user of the device must make sure whether
or not the device may be connected, if necessary by contacting the power
supply company.
Information on
Noise Emission
Values
The inverter generates a maximum sound power level of <80dB(A) (ref.
1pW) at full-load operation according to IEC 62109-1.
The cooling of the device takes place via an electronic temperature control
system at the lowest possible noise level and depends on the power used,
ambient temperature and the soiling level of the device, etc.
A workplace-related emissions value cannot be provided for this device
because the actual noise level that occurs depends strongly on the installati-
on situation, the grid quality, the surrounding walls and the general properties
of the space.
EMC Device
Classifications
Devices in emission class A:
- Are only designed for use in industrial settings
- Can cause grid-bound and radiated interference in other areas
Devices in emission class B:
- Satisfy the emissions criteria for residential and industrial areas.
This is also true for residential areas in which the energy is
supplied from the public low-voltage grid.
EMC device classification as per the rating plate or technical data

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Equipment with the CE marking fulfils the basic requirements of the Guideli-
ne Governing Low-Voltage and Electromagnetic Compatibility. (For more
information, please see the attachment and/or the “Technical Data“ section in
your documentation).
Safety Markings
The user is responsible for backing up data relating to changes made to
factory settings. The manufacturer will not accept liability if personal settings
are deleted.
Data Security
The manufacturer maintains the copyright to these operating instructions.
Text and illustrations are technically correct at the time of going to print. The
right to make modifications is reserved. The contents of the operating in-
structions shall not provide the basis for any claims whatsoever on the part
of the purchaser. We would be grateful for any comments or suggestions
regarding improvements and/or error corrections for the operating instruc-
tions.
Copyright
This device should not be disposed of in residential waste.
To comply with European Directive 2002/96/EC on Waste Electrical and
Electronic Equipment and its implementation as national law, electrical
equipment that has reached the end of its life must be collected separately
and returned to an approved recycling facility. Any device that you no longer
require must be returned to your dealer or you must find an approved collec-
tion and recycling facility in your area.
Ignoring this EU Directive may have adverse affects on the environment and
your health.
Disposal
Danger of damage to electronic components due to electrostatic discharge.
Take appropriate ESD precautions when replacing and installing compon-
ents.
ESD Precautions
Electrical Installa-
tions
Electrical installations may only be carried out in accordance with relevant
national and local standards and regulations.
The device should only be operated when all safety equipment is fully func-
tional. If safety equipment is not fully functional, there is a danger to:
- the life and well-being of the operator or third parties
- the equipment and other property of the owner/operator
- the efficient operation of the equipment
Safety equipment that is not fully functional must be repaired by an authori-
zed specialist before the device is turned on.
Never bypass or disable safety equipment.
Safety Precauti-
ons in Normal-
Operation

1
EN
Contents
General remarks ........................................................................................................................................... 2
Copyright .................................................................................................................................................. 2
Introduction .............................................................................................................................................. 2
Function ................................................................................................................................................... 2
System requirements ............................................................................................................................... 2
Before commissioning ................................................................................................................................... 3
Introduction .............................................................................................................................................. 3
Utilisation in accordance with „intended purpose“ .................................................................................... 3
Open housing ................................................................................................................................................ 3
Housing .................................................................................................................................................... 3
Fuses ............................................................................................................................................................ 4
Inserting fuses .......................................................................................................................................... 4
Fuse protection dependent on the solar modules .................................................................................... 5
Criteria for selecting the correct fuse ....................................................................................................... 5
Fuse recommendations ........................................................................................................................... 5
Ordering fuses ......................................................................................................................................... 6
Setting the address ....................................................................................................................................... 6
Safety ....................................................................................................................................................... 6
Jumper and adjusting dials ...................................................................................................................... 6
Setting the Solar Net address .................................................................................................................. 6
Installation ..................................................................................................................................................... 7
Choosing location - general remarks ....................................................................................................... 7
Fitting wall bracket ................................................................................................................................... 7
Connections in the housing ........................................................................................................................... 9
General remarks ...................................................................................................................................... 9
(+) cable for Fronius IG ............................................................................................................................ 9
(-) cable for Fronius IG ............................................................................................................................. 9
DatCom cable ........................................................................................................................................ 10
Special case: external mains adapter .................................................................................................... 10
Closing the housing ...................................................................................................................................... 11
Housing ................................................................................................................................................... 11
Connecting the solar module strings ........................................................................................................... 12
Safety ..................................................................................................................................................... 12
Plugging in the solar module strings ...................................................................................................... 12
Settings ....................................................................................................................................................... 13
General remarks .................................................................................................................................... 13
Number of strings per measuring channel ............................................................................................. 13
Maximum deviation ................................................................................................................................ 13
Threshold [Ah] ........................................................................................................................................ 13
Ultrasonic signal ON/OFF ...................................................................................................................... 13
Data display ................................................................................................................................................. 14
„Now“ ..................................................................................................................................................... 14
Analysis .................................................................................................................................................. 14
Status messages ......................................................................................................................................... 14
General remarks .................................................................................................................................... 14
Technical data ............................................................................................................................................. 15
Special voltage ....................................................................................................................................... 15
Fronius String Control ............................................................................................................................ 15
Declaration of conformity ............................................................................................................................ 16

2
General remarks
Copyright The copyright to these operating instructions remains the property of Fronius Internatio-
nal GmbH. Text and illustrations were accurate at the time of printing. Subject to change
without notice. We are grateful for any suggestions for improvement and for drawing our
attention to any errors in these instructions.
The contents of the instruction manual shall not provide the basis for any claims
whatsoever on the part of the purchaser. Fronius International GmbH shall not be liable
for any damage (including loss of profit or any other financial loss) attributable to the use
of, or impossibility of using, this device.
Introduction The Fronius String Control 125/25 is a system add-on for mains-connected Fronius IG
300, 390, 400 and 500 inverters. The Fronius String Control 125/25 combines 5 solar
module strings in one measuring channel. The Fronius String Control 125/25 compares
the current of each measuring channel with the average value of all channels. Any
excessive deviation will result in a status message. The user is free to define what an
acceptable deviation is.
„Fronius Solar.access“ software and the Fronius IG datalogger also support the sending
of status messages by e-mail or SMS for Fronius String Control 125/25. This allows a
faulty solar module to be detected quickly.
In addition, the Fronius String Control 125/25 bundles all solar module strings into one
single positive and negative pole. Slots are provided for fuses. Provided that the correct
fuses have been chosen, each individual string is protected against overcurrent.
Function The Fronius String Control 125/25 has 5 measuring channels for each of the 5 strings.
This gives up to 25 string connections. The 5 measuring channels record the total
current of each of the strings connected over the whole charging day. In the evening, the
Fronius String Control 125/25 uses these figures to calculate an average value for all
measuring channels. If the Fronius String Control 125/25 detects that one of the measu-
ring channels deviates too much from the average, a status message is sent to the
Fronius IG Datalogger.
System require-
ments
- Fronius IG 300, 390, 400 or 500
- Fronius IG Datalogger
- PC with installed Fronius Solar.access software

3
EN
WARNING! Operating the equipment incorrectly can cause serious injury and
damage. Do not use the functions described here until you have read and
completely understood all of the following documents:
- these Operating Instructions
- all operating instructions for the system components, especially the
„Safety rules“
The device is intended solely for use as a collector and measuring device for the solar
module DC strings. The device may only be operated with the Fronius IG 300, 390, 400
and 500.
Utilisation for any other purpose, or in any other manner, shall be deemed to be „not in
accordance with the intended purpose“. The manufacturer shall not be liable for any
damage resulting from such improper use.
Utilisation in accordance with the “intended purpose” also comprises
- following all the instructions given in this manual
WARNING! Danger from DC voltage in solar modules. The Fronius String
Control 125/25 may only be opened in a de-energised state by a qualified
1. Loosen two screws (1) on each side
of the housing
2. Remove cover (2)
Fig. 1 Opening the housing
(1)
Before commissioning
Introduction
Utilisation in
accordance with
„intended purpo-
se“
Open housing
Housing
WARNING! Operating the equipment incorrectly can cause serious injury and
damage. The following activities must only be carried out by qualified electrici-
ans! Note the safety rules in these operating instructions.
(1)
(1)
(2)
(1)

4
Fuses
Inserting fuses
NOTE! For protect the Fronius String Control 125/25, only use fuses that
comply with the criteria for selecting the correct fuses. For further details, read
all the section entitled „Fuses“.
Fuses are absolutely essential for operating the String Control 125/25. Fuses
are not supplied.
1. Each fuse holder (1) corresponds to one solar module string
2. There are 5 fuse holders for each measuring channel (2)
3. There are 5 measuring channels in total
4. Labelling is situated
- on the connections for the solar module strings (3)
- on the fuse holders
5. Example: 4/5 = measuring channel 4, string 5
6. Place a suitable fuse in the corresponding fuse holder
Fig. 3 Connection plate
Fig. 2 Fuse holder
(3)
(1)
(2)
WARNING! Danger from DC voltage in solar modules. The Fronius String
Control 125/25 may only be opened in a de-energised state by a qualified

5
EN
Fuse protection
dependent on the
solar modules
Fuse protection of the individual module strings depends on which solar modules are
present. A crucial factor is the maximum short circuit current (ISC) of the solar module
concerned.
Criteria for
selecting the
correct fuse
The fuse for a solar module string must satisfy the following criteria:
1. IN> 1.5 x ISC
2. IN< 2.00 x ISC
3. UN>/= 530 V DC
4. Fuse dimensions: 10.3 x 35 - 38 mm
Key:
IN: Nominal current value of the fuse
ISC: Short circuit current for standard test conditions according to solar module data
sheet
UN: Nominal voltage value of the fuse
NOTE! In underrated fuses, the nominal current value is less than the short
circuit current of the solar module.
Effect:
The fuse may trip in intensive lighting conditions.
Fuse recommen-
dations
Fronius recommends Littelfuse fuses. The criteria for selecting the correct fuses must be
satisfied.
NOTE! Only select fuses suitable for a voltage of 530 V DC!
e.g.: Maximum short circuit current (ISC) of the solar module = 5.75 A
According to the criteria for selecting the correct fuse, the fuse must have a nominal
current greater than 1.5 times the short circuit current:
5.75 A x 1.5 = 8.625 A
Fuse to be selected: Littelfuse KLKD-10 with 10.0 A and 530 V AC/DC
Nominal current Fuse
1.0 A KLKD-1
2.0 A KLKD-2
3.0 A KLKD-3
4.0 A KLKD-4
5.0 A KLKD-5
Nominal current Fuse
10.0 A KLKD-10
15.0 A KLKD-15
20.0 A KLKD-20
25.0 A KLKD-25
30.0 A KLKD-30

6
Setting the address
Fig. 4 Jumpers and adjusting dials
The procedure can be seen in the examp-
les illustrated.
(1) (2) (3)
00 1
Fig. 5 Solar Net address
The Solar Net allows up to 200 Fronius
String Controls 125/25 to be operated
simultaneously. The Fronius String Cont-
rols 125/25 are allocated addresses to
distinguish them from one another. To set
the address (0 to 199), use
- jumper (1)
- adjusting dial (2)
- adjusting dial (3)
Jumper and
adjusting dials
Setting the Solar
Net address Fronius String
Control 125/25
No.:
03 7
12 3
1
37
123
Safety
Ordering fuses Fuses with nominal values of 5 A, 10 A and 20 A can be ordered from Fronius by quoting
the following item numbers:
- Littelfuse KLKD-5 (41,0007,0205)
- Littelfuse KLKD-10 (41,0007,0207)
- Littelfuse KLKD-20 (41,0007,0200)
WARNING! The solar modules operate at high voltage. Before performing any
work on the Fronius String Control 125/25, de-energise the solar module

7
EN
Installation
Note the following criteria:
- Install on firm surface
- The ambient temperature must be between -20 °C and +40 °C
- IP 45 means that the Fronius String Control 125/25 can be exposed to moisture.
However we recommend that the device is not exposed directly to moisture.
- The Fronius String Control 125/25 can be installed vertically or horizontally - see
section „Fitting wall bracket“.
IP 45 also means that the device can be installed outside. Fronius String Control 125/25
- should be protected from direct sunlight and direct exposure to the elements
- should be installed below the solar module where possible
Choosing locati-
on - general
remarks
Fitting wall
bracket
To allow any water ingress to escape:
- Remove drain plug (1) when installing
vertically
- Remove drain plug (2) when installing
horizontally
(2)
(1)
Important! The wall bracket can be fitted as shown for both vertical and horizontal
installation of the Fronius IG.
Fig. 6 Vertical installation position Fig. 7 Horizontal installation position
Fig. 8 Drain plugs

8
The following illustration shows both parts
(1) and (2) of the wall bracket. Both parts
are enclosed with the Fronius String
Control 125/25.
To fit part (2), proceed as follows:
- Loosen screws (3) on the underside
of the Fronius String Control 125/25
- Fit part (2) using screws (3)
Fitting wall
bracket
(continued)
Fig. 9 Parts for wall bracket
(1)
(3)
(2)
(2x)
(1)
(4) (5)
(4)
(5)
NOTE! As the choice of dowels and screws will depend on the subsurface,
these are not included.
1. Fit part (1) of the wall bracket to a firm surface using suitable screws (4) and dowels
(5)
354 mm
Fig. 10 Fitting the wall bracket Fig. 11 Fitted wall bracket
2. Attach Fronius String Control 125/25 to part (1) of the wall bracket
3. Fit part (2) of the wall bracket using suitable screws and dowels
CAUTION! Risk of injury and damage from falling device if the Fronius String
Control 125/25 is not secured with part (2) of the wall bracket. Attach Fronius
String Control 125/25 to part (1) of the wall bracket and secure using part (2)
of the wall bracket.

9
EN
1. Feed (+) cable (1) through metric
screw joint (2)
2. Using the following installation materi-
als, fit (+) cable (1) to (+) bolt (3)
(torque 28 Nm):
- Washer (4)
- Friction washer (5)
- Hexagon nut (6)
3. Tighten metric screw joint (2)
Fig. 12 Connecting (+) cable
Fig. 13 Connecting (-) cable
1. Feed (-) cable (1) through metric
screw joint (2)
2. Using the following installation materi-
als, fit (-) cable (1) to (-) bolt (4)
(torque 28 Nm):
- Spacer (3)
- Washer (5)
- Friction washer (6)
- Hexagon nut (7)
3. Tighten metric screw joint (2)
Important! Note the following when fitting the positive and negative cables:
- Attach an M12 cable lug to the positive and negative cables
- The metric screw joint for the positive and negative cables is size M32
This means that the metric screw joint is suitable for cables with diameters from 11 to 22
mm.
Connections in the housing
General remarks
(+) cable for
Fronius IG
(-) cable for
Fronius IG
WARNING! The solar modules operate at high voltage. Before performing any
work on the Fronius String Control 125/25, de-energise the solar module
Important! In addition to the metric screw joints for the (+) and (-) cables are two additio-
nal bushings with blanking covers. The bushings are intended for two M16 screw joints.
These M16 joints allow the user to connect additional cables (16 mm²) to the (+) and (-)
bolts for external lightning protection.
(1)
(2)
(3)
(5)
(6)
(4)
(1)
(2)
(3)
(7)
(5)
(6)
(4)

10
NOTE! In certain situations the
power supply from the Solar Net
may not be sufficient. This is
especially true in the case of
additional DatCom components.
It also applies when the DatCom
cables between the Fronius IG
and Fronius String Control 125/25
are longer than 100 m.
An external mains adapter is provided for
such a situation.
Fig. 15 Connecting the mains adapter
Because of the easier access, we recommend that whenever possible the adapter be
plugged into a DatCom component other than the Fronius String Control 125/25.
However, if there is no other more easily accessible DatCom component, proceed as
follows:
1. Open housing as described in the section „Opening the housing“
2. Loosen metric screw joint (1)
3. Feed mains cable (2) and the DatCom cables through metric screw joint (1)
4. Plug mains cable (2) into socket (3)
5. Tighten metric screw joint (1)
6. Close housing as described in section „Closing the housing“
DatCom cable NOTE! If only one DatCom cable
(1) is connected, insert a termina-
ting plug in one of the two so-
ckets (2).
The terminating plug is supplied with the
Fronius IG Datalogger.
1. Open metric screw joint (3)
2. Remove insert (4)
3. Clamp DatCom cable into both
openings on the insert (4)
Fig. 14 Connecting the DatCom cable
(3)(1)
(1)
(2)
(1)
(3) (2)
Special case:
external mains
adapter
NOTE! If only one DatCom cable is clamped, insert the bolt supplied (5) into the
second opening.
4. Place the insert (4) (and the DatCom cables) into the metric screw joint (3)
5. Plug DatCom cables (1) into the sockets (2)
6. Tighten metric screw joint (3)
(4)
(5)

11
EN
1. Fit cover (2)
2. Tighten two screws (1) on each side
of the housing
Fig. 16 Closing the housing
Closing the housing
Housing
(1)
(1)
(1)
(2)
(1)

12
Connecting the solar module strings
WARNING! The solar modules operate at high voltage. Before performing any
work on the Fronius String Control 125/25, de-energise the solar module
Fig. 17 Connection plate
Safety
Plugging in the
solar module
strings
NOTE! When connecting the solar modules and when making the DC connec-
tions, ensure that the polarity of the solar modules matches the „+“ and „-“
symbols.
- Connect DC plugs to the positive and negative poles on the solar module strings
- Plug the solar module strings into the Fronius String Control 125/25
NOTE! Never remove the DC plug from the plug contacts while the Fronius IG
is charging. Before unplugging the solar module strings, always unplug the
mains supply first or switch the Fronius IG to standby mode.
The plug contacts may be damaged if this instruction is ignored.
If an arc appears while unplugging, the plug and socket must both be replaced.
Do not use DC plugs if they are damaged.
The number of DC plug connections depends on the number ordered. If the
Fronius String Control 125/25 has fewer than 25 strings, the remaining ope-
nings are sealed with water-tight blanking covers.
NOTE! DC plugs not in use must be covered with the enclosed protective caps.
NOTE! Never connect more than 25 A DC in total to each measuring channel.
Never connect more than 20 A DC to each string.