SMA SUNNY STRING-MONITOR Technical Description
SSM-TEN103132 | 98-4000932 | Version 3.2
EN
Accessories for Central inverter
SUNNY STRING-MONITOR
Technical Description
SMA Solar Technology AG Table of Contents
Technical Description SSM-TEN103132 3
Table of Contents
1 Notes on this manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1 Validity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2 Target Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3 Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4 Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1 Appropriate Usage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Parallel Connection of Strings. . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.1 Maximum Number of Connections per Measurement Input. . . . . . . . . . . . . 10
2.2.2 Reverse Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3 Safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.3.1 Short-circuit current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.3.2 Information on Grounded PV Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.3.3 Reverse Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.4 Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3 Packing list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.1 Sunny String-Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2 Identification of the Sunny String-Monitor. . . . . . . . . . . . . . . . . 14
3.3 Checking the Sunny String-Monitor for Transport Damage . . . 14
3.4 Storing the Sunny String-Monitor . . . . . . . . . . . . . . . . . . . . . . . 14
3.5 Structure of the Sunny String-Monitor . . . . . . . . . . . . . . . . . . . . 15
4 Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1 Selecting the Mounting Location. . . . . . . . . . . . . . . . . . . . . . . . 17
4.2 Assembling the Sunny String-Monitor . . . . . . . . . . . . . . . . . . . . 18
5 Electrical Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table of Contents SMA Solar Technology AG
4 SSM-TEN103132 Technical Description
5.1 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.2 Overview of the Connection Area . . . . . . . . . . . . . . . . . . . . . . 21
5.3 Closing and Opening the Sunny String-Monitor. . . . . . . . . . . . 23
5.4 Connecting the PV strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.4.1 Connect the PV Strings to the Spring Clamp Terminals. . . . . . . . . . . . . . . . . 24
5.4.2 Connect the PV Strings to the SUNCLIX DC Plug Connectors. . . . . . . . . . . . 24
5.4.3 Connect the PV Strings to the Tyco, MC3 and MC4 Plugs. . . . . . . . . . . . . . 26
5.5 Connecting the DC Main Cable. . . . . . . . . . . . . . . . . . . . . . . . 26
5.6 Connecting to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.7 Connecting the Data Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.7.1 Data Cable Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.7.2 Connect the Data Cable Shield Contact. . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.7.3 Connecting the Data Cable in the Sunny String-Monitor . . . . . . . . . . . . . . . 28
5.7.4 Connecting the Data Cable in the Sunny Central . . . . . . . . . . . . . . . . . . . . . 30
5.7.5 Terminating the Data Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.8 Connecting the Remote Tripping for the DC Circuit Breaker. . . 32
5.8.1 Dimensioning the Connection Cable for the Operating Current Release . . . 32
5.8.2 Dimension the Connection Cable for the Undervoltage Release . . . . . . . . . 34
5.8.3 Connect Shunt Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.8.4 Connecting the Feedback Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.9 Install Anti-Theft Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
5.10 Identification of the Piggy-Back for Data Processing. . . . . . . . . 36
6 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
6.1 Commissioning the Sunny String-Monitor . . . . . . . . . . . . . . . . . 37
6.2 Switching On the Sunny String-Monitor . . . . . . . . . . . . . . . . . . 38
6.3 Disconnecting the Sunny String-Monitor . . . . . . . . . . . . . . . . . . 39
6.4 Reconnect the DC Circuit Breaker after Tripping . . . . . . . . . . . 40
7 Configure Sunny String-Monitor . . . . . . . . . . . . . . . . . . . . 41
7.1 Configure the Sunny String-Monitor via Sunny Central Control 41
SMA Solar Technology AG Table of Contents
Technical Description SSM-TEN103132 5
7.1.1 Organizing the Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
7.1.2 Check the Serial Interface Settings at the Sunny Central Control . . . . . . . . . 42
7.1.3 Detecting Sunny String-Monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
7.1.4 Setting the Device Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
7.1.5 Deleting detected Sunny String-Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
7.2 Configure the Sunny String-Monitor with Sunny Data Control . 44
7.2.1 Setting the Required Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
7.2.2 Configuring Sunny String-Monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
8 Function of the String Current Monitoring . . . . . . . . . . . . 48
8.1 Requirements for Activating the String Current Monitoring. . . . 48
8.2 Functionality of the String Current Monitoring . . . . . . . . . . . . . 48
8.3 Setting the Parameters Using Sunny Central Control . . . . . . . . 51
8.3.1 Setting the Number of Strings per Measuring Channel . . . . . . . . . . . . . . . . 51
8.3.2 Setting the Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8.3.3 Setting the Tripping Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8.3.4 Setting the Tolerance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
8.3.5 Setting the Time Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
8.3.6 Setting overnight shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
8.3.7 Setting Anti-Theft Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
8.4 Setting the Parameters Using Sunny Data Control . . . . . . . . . . 54
8.4.1 Overview of the Program Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
8.4.2 Setting the Number of Strings per Measuring Channel . . . . . . . . . . . . . . . . 54
8.4.3 Setting the groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.4.4 Setting the Time Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.4.5 Setting the Tripping Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.4.6 Setting the Tolerance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
8.4.7 Setting overnight shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.4.8 Setting Anti-Theft Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.5 Reading the Measurement Values in Sunny Central Control . . 56
8.5.1 Reading the Mean Values of the Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
8.5.2 Reading the Mean Values for the Individual Measurement Channels . . . . . 56
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6 SSM-TEN103132 Technical Description
8.6 Reading the Measurement Values in Sunny Data Control . . . . 57
8.7 Reading the Messages in Sunny Central Control . . . . . . . . . . . 58
8.7.1 Reading and Confirming Current Messages. . . . . . . . . . . . . . . . . . . . . . . . . 58
8.7.2 Reading and Confirming the Event History . . . . . . . . . . . . . . . . . . . . . . . . . . 58
9 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
10 Technical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
11 Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
SMA Solar Technology AG 1Notes on this manual
Technical Description SSM-TEN103132 7
1 Notes on this manual
1.1 Validity
This technical description describes the installation and operation the Sunny String-Monitor.
1.2 Target Group
This manual is intended for installers and operators of PV plants equipped with the Sunny Central and
Sunny String-Monitor.
1.3 Additional Information
You will find further information on the Sunny String-Monitor in the download area of
www.SMA.de/en. Keep the documentation of the Sunny String-Monitor and of the installed
components with the system documentation. They must be accessible at all times.
The documents listed below are included in the delivery of your Sunny String-Monitor. The following
information is contained in these documents.
• Technical Description Installation and operation of the Sunny String-Monitor
• Additional documentation
1Notes on this manual SMA Solar Technology AG
8 SSM-TEN103132 Technical Description
1.4 Symbols Used
The following types of safety instructions and general information appear in this document:
☑ This symbol indicates the result of an action.
✖ This symbol indicates a possible error.
%"/(&3
"DANGER" indicates a hazardous situation which, if not avoided, will result in death or
serious injury.
8"3/*/(
"WARNING" indicates a hazardous situation which, if not avoided, could result in death
or serious injury.
$"65*0/
"CAUTION" indicates a hazardous situation which, if not avoided, could result in minor
or moderate injury.
/05*$&
NOTICE indicates a situation that can result in property damage if not avoided.
Information
Information provides tips that are important for the optimal operation of your product.
SMA Solar Technology AG 2Safety
Technical Description SSM-TEN103132 9
2Safety
2.1 Appropriate Usage
The Sunny String-Monitor is an accessory for the Sunny Central central inverter. The DC subdistributor
offers the possibility of connecting several strings in parallel. The Sunny String-Monitor monitors and
recognizes outages and thus prevents loss of power and output. The string fuses in the Sunny StringMonitor disconnect defective strings which, for example, have been damaged due to a short-circuit
in the module or in the cabling of the PV array.
The Sunny String-Monitor allows monitoring of the integrated overvoltage protectors. The overvoltage
protectors protect the inverters from transient overvoltages.
Figure1:Principle of a grid-tied PV plant
Position Description
APV array
B Sunny String-Monitor SSM
C Sunny Central
D Transformer
EPublic grid
A
B
C
D
E
S
M
A
S
U
N
N
Y
C
E
N
T
R
A
L
8
0
0
C
P
S
M
A
2Safety SMA Solar Technology AG
10 SSM-TEN103132 Technical Description
Figure2:Block circuit diagram of the Sunny String-Monitor in the PV system
2.2 Parallel Connection of Strings
2.2.1 Maximum Number of Connections per Measurement Input
Several PV strings can be connected in parallel in the Sunny String-Monitor. The maximum number of
PV strings connected in parallel depends on the adjustable tolerance, and can be determined as
follows:
N = maximum number of PV strings that can be connected in parallel.
The parameter "tolerance" can be adjusted in the Sunny Central Control.
Maximum Number of Strings
The maximum number of PV strings that can be connected in parallel is limited to 9, if the
tolerance is set to 10 %. If more than 9 PV strings are connected in parallel at this level
of tolerance, the failure of a PV string cannot be recognized.
• Adhere to the maximum number of PV strings which can be connected in parallel.
SMA Solar Technology AG 2Safety
Technical Description SSM-TEN103132 11
2.2.2 Reverse Current
A reverse current may arise when different open circuit voltages are present at modules mounted in
parallel. In this event, the reverse current can be much higher than the module's short circuit current.
The higher the reverse current, the higher the heat will rise in the modules of the faulty PV strings.
Pronounced warming can destroy the modules of the faulty PV strings.
Figure3:Possible reverse currents in the PV array
The following points can cause a reverse current:
• Short circuit in one or more modules,
• Short circuit in one or more cells in a module
• Double ground fault in a module
• Double ground fault in the cabling
The Sunny String-Monitor contains string fuses. They trip when the string current is too high and thus
protect the modules of the faulty PV strings. The Sunny String-Monitor informs Sunny Central Control
of the failure of the PV strings. The Sunny Central Control displays the warning "SMU".
2Safety SMA Solar Technology AG
12 SSM-TEN103132 Technical Description
2.3 Safety instructions
2.3.1 Short-circuit current
The short circuit current of the PV array is only slightly higher than the maximum operating current and
also depends on irradiation conditions. If a short-circuit occurs in the system, the available fuses are
not guaranteed to switch off.
%"/(&3
Risk of lethal electric shock.
• Work on the Sunny String-Monitor may only be performed after switching off the power to the
unit in accordance with the regulations applicable to the installation site:
– Disconnect
– Ensure that the device cannot be reconnected
– Ensure that no voltage or current is present
– Cover or isolate adjacent live elements
%"/(&3
Risk of lethal electric shock. The fuse holders are also energized when the string fuse is
disconnected.
• The Plexiglas covers must always be mounted, to ensure protection against direct touching.
• Only insert the fuses when wearing personal protective equipment.
• Only plug in or unplug the Solar Plug when no current is present.
8"3/*/(
Danger of electric shock due to incorrect procedure. Serious injuries, burns and material
damage.
• All work on the Sunny String-Monitor must be carried out strictly according to the instructions
in this guide.
• Observe all safety precautions.
• Wear personal protective equipment during work on electrical devices.
• Immediately rectify failures that affect or limit the safety of the device.
• Unauthorized personnel must not have access to the devices.
Warning Signs
• Signs must always be attached in prominent positions and must be promptly replaced if
damaged.
SMA Solar Technology AG 2Safety
Technical Description SSM-TEN103132 13
2.3.2 Information on Grounded PV Plants
The positive or negative pole of the PV array can be grounded within the Sunny Central via a GFDI
(Ground Fault Detection Interruption) fuse.
• Additional grounding within the PV array or floor-mounted distribution board is not permissible.
The grounding of the PV array can be automatically interrupted by the GFDI at any time.
• The GFDI ensures plant protection, but does not protect persons.
You will find additional information on grounded PV plants in the Sunny Central documentation and
in the download area of www.SMA.de/en.
2.3.3 Reverse Voltage
On the main DC cables in the Sunny String-Monitor there is a permanent reverse voltage present of
up to 1000 VDC of the Sunny Central. When the power is off, the reverse voltage can be interrupted
by pulling the DC fuses in the Sunny Central.
2.4 Personnel
Only qualified technical personnel may perform work on the Sunny String-Monitor. Qualified means
that the personnel must possess training relevant to the activity performed and must be familiar with
the content of this manual.
2.5 General Information
Communication between Sunny String-Monitor and Sunny Central
Alongside the Sunny String-Monitor SSM one can also install the Sunny String-Monitor SSM16-11 as
well as the Sunny String-Monitor SSM24-11 for string monitoring These have various numbers of
Piggy-Backs for data processing.
Maximum number of Piggy-Backs for data processing
There are two communications connections in each Sunny Central, to which up to 10
Piggy-Backs each can be connected. The number of Piggy-Backs for data processing is
thus determined by the combination possibilities between the Sunny String-Monitor SSM,
Sunny String-Monitor SSM16-11 and Sunny String-Monitor SSM24-11. The following
summary shows the number of Piggy-Backs for data processing in the various Sunny
String-Monitor:
• Sunny String-Monitor SSM: 1 Piggy-Back for data processing.
• Sunny String-Monitor SSM16-11: 2 Piggy-Backs for data processing.
• Sunny String-Monitor SSM24-11: 3 Piggy-Backs for data processing.
3Packing list SMA Solar Technology AG
14 SSM-TEN103132 Technical Description
3Packing list
3.1 Sunny String-Monitor
Figure4:Packing list
3.2 Identification of the Sunny String-Monitor
The type label serves to identify the Sunny String-Monitor. The type label is found on the mounting
plate in the upper middle, next to the big measurement circuit board. On the type label there is the
following information:
• Type (Type / Model)
•Serial number (Serial No.) of the Sunny String-Monitor.
3.3 Checking the Sunny String-Monitor for Transport Damage
• Check the device and its packaging for damage.
• Compare the delivery contents against the delivery papers.
• If the device is damaged or if there are discrepancies in the content of the delivery, contact your
supplier.
3.4 Storing the Sunny String-Monitor
• Only store the Sunny String-Monitor in areas where it is protected from dust and dampness.
Position Number Description
A 1 Sunny String-Monitor
B 1 Technical description
C 8 / 16 Fuses
D 8 / 16 DC plug connector
*
*
optional
E 8 / 16 Sealing plugs for DC plug connectors
*
SMA Solar Technology AG 3Packing list
Technical Description SSM-TEN103132 15
3.5 Structure of the Sunny String-Monitor
Depending on the option chosen, the Sunny String-Monitor may have a DC circuit breaker and may
be equipped with a different number or string connections. For the selection of Sunny String-Monitor
options or fittings use the option code in the price list. It determines both the assembly and recognition
of the Sunny String-Monitor.
Terminals, for the connection of the RS485 communication and the +55 V
DC
power supply are
provided in the connection area. In addition, the connection area provides a contact for the data
cable shield.
String monitoring takes place via the measurement circuit board in the Sunny String-Monitor, where a
Piggy-Back for data processing (SMU8HV-DVPB) is integrated. The SMU8HV-DVPB assumes string
current management and the measurement board's parameter settings. Two bolt clamps are
integrated into the Sunny String-Monitor to connect the DC main cable to the inverter.
The DC circuit breaker offers the option of disconnecting the Sunny String-Monitor on the inverter side.
In the case of grounded PV arrays, the positive or the negative pole can be grounded at the inverter.
In this case, cylindrical bridges are used instead of fuses in the Sunny String-Monitor.
For protection from transient overvoltages caused by lightning strikes, overvoltage protectors are built
into the Sunny String-Monitor. A grounding terminal is provided for connection of the equipotential
bonding.
Depending on the selected fittings, the interior view of a Sunny String-Monitor can differ from the
depicted maximum assembly options.
Figure5:Main components inside
Position Description
A Mounting brackets
BC
DE
F
KLMNOPR
1 2
3 4 5 6
G
A
QA
A
A
A AHI
3Packing list SMA Solar Technology AG
16 SSM-TEN103132 Technical Description
B Communication Piggy-Back
C Jumper for data cable termination
D Piggy-Backs for data processing
E Operating status LEDs
F Overvoltage protector
GDC circuit breaker
H Connection of the feedback signal contact
I Shunt release drive connection
K Main DC cable connection, ‒ pole
L DC fuses or cylindrical bridges
MString connections, ‒ pole
NGround connection
O Communication Connection
P String connections, + pole
Q DC fuses or cylindrical bridges
R Main DC cable connection, + pole
Position Description
SMA Solar Technology AG 4Mounting
Technical Description SSM-TEN103132 17
4Mounting
4.1 Selecting the Mounting Location
• Do not install the Sunny String-Monitor in an emergency exit path, or in a living or office area.
• Choose a location which can support the weight of the Sunny String-Monitor.
• Choose a location with low interference field strengths.
• Mount the Sunny String-Monitor so as to allow easy access for service work.
• Mount the Sunny String-Monitor so that it is protected from direct irradiation.
• Mount the Sunny String-Monitor so that it is as protected from rain as is possible.
• Provide for external strain relief.
• Mount the Sunny String-Monitor level on a wall or a stand, so that the connection area is
pointing downward.
• Do not mount the Sunny String-Monitor flat on its back or leaning.
%"/(&3
Danger to life due to fire or explosion.
• Do not install the Sunny String-Monitor on flammable construction materials.
• Do not install the Sunny String-Monitor near highly flammable materials.
• Do not install the Sunny String-Monitor in potentially explosive areas.
Example:
In the case of a rack-mounted PV array, the Sunny StringMonitor can ideally be positioned directly behind the PV
array in the shadow.
SM
A
4Mounting SMA Solar Technology AG
18 SSM-TEN103132 Technical Description
4.2 Assembling the Sunny String-Monitor
Required material:
• 6 screws, 6 mm diameter, 4 screws if no DC circuit breaker Consider the wall properties when
choosing the screws.
• 6 washers, 4 if no DC circuit breaker
• 6 dowels, 4 if no DC circuit breaker
The following graphic shows the dimensions of the Sunny String-Monitor with DC circuit breaker.
/05*$&
Damage to the cable glands and plug connections due to improper transport and
installation.
The cable glands and plug connections protrude from the enclosure.
• When transporting and mounting the Sunny String-Monitor, ensure that the cable glands and
plugs are not damaged.
/05*$&
Damage to the electronics due to moisture penetration.
• Carry out installation work only under favorable weather conditions.
SMA Solar Technology AG 4Mounting
Technical Description SSM-TEN103132 19
The following graphic shows the dimensions of the Sunny String-Monitor without DC circuit breaker.
1. Mark the position of the drill holes.
2. Drill holes at the marked positions.
3. Insert floor anchors.
4. Fasten the Sunny String-Monitor to the wall or stand
using suitable screws and washers.
5. Make sure that the device is securely in place.
5Electrical Connection SMA Solar Technology AG
20 SSM-TEN103132 Technical Description
5 Electrical Connection
5.1 Safety
%"/(&3
Risk of lethal electric shock if the DC cable connected to the PV array is touched. The PV
modules exposed to light have voltages present.
•Cover the PV modules.
• Follow all safety instructions of the module manufacturer.
• Remove the appropriate DC fuses in the Sunny Central, and, if present, the Sunny Main Box.
• Disconnect the Sunny Central.
/05*$&
Damage to the electronics due to moisture penetration.
• Installation work should be carried out only during favorable weather conditions.
SMA Solar Technology AG 5Electrical Connection
Technical Description SSM-TEN103132 21
5.2 Overview of the Connection Area
Figure6:Terminals and plugs for connections
Position Description
A Jumper for data cable termination
BSignal contact for the anti-theft protection
C Terminals for the connection of the feedback signal contact
*
*
optional
D Terminals for the connection of the shunt release drive
E Bolt clamp to connect the DC main cable, - pole
F Spring-type terminals for the string connections, - pole
**
**
if connecting the strings directly
G Plug for the connection of the strings, - pole
H Terminals for the ground connection
I Terminals for the connection of the data cable and voltage supply
K Plug for the connection of the strings, + pole
L Spring-type terminals for the string connections, + pole**
M Bolt clamp to connect the DC main cable, + pole
A
EFGHIM
1 2
3 4 5 6
L+
L+
L
K
DC
B
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