SMA MULTICLUSTER-BOX 12 User manual

SUNNY ISLAND
MULTICLUSTER BOX
MC-BOX-12-3-20-BE-en-13 | Version 1.3ENGLISH
Operating manual
MULTICLUSTER-BOX 12

Legal Provisions SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-132
Legal Provisions
The information contained in these documents is the property of SMA Solar Technology AG. No part of this document
may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, be it electronic,
mechanical, photographic, magnetic or otherwise, without the prior written permission of SMA Solar Technology AG.
Internal reproduction used solely for the purpose of product evaluation or other proper use is allowed and does not
require prior approval.
SMA Solar Technology AG makes no representations or warranties, express or implied, with respect to this
documentation or any of the equipment and/or software it may describe, including (with no limitation) any implied
warranties of utility, merchantability, or fitness for any particular purpose. All such representations or warranties are
expressly disclaimed. Neither SMA Solar Technology AG nor its distributors or dealers shall be liable for any indirect,
incidental, or consequential damages under any circumstances.
The exclusion of implied warranties may not apply in all cases under some statutes, and thus the above exclusion may
not apply.
Specifications are subject to change without notice. Every attempt has been made to make this document complete,
accurate and up-to-date. Readers are cautioned, however, that product improvements and field usage experience may
cause SMA Solar Technology AG to make changes to these specifications without advance notice, or per contract
provisions in those cases where a supply agreement requires advance notice. SMA Solar Technology AG shall not be
responsible for any damages, including indirect, incidental or consequential damages, caused by reliance on the
material presented, including, but not limited to, omissions, typographical errors, arithmetical errors or listing errors in
the content material.
SMA Warranty
You can download the current warranty conditions from the Internet at www.SMA-Solar.com.
Trademarks
All trademarks are recognized, even if not explicitly identified as such. Missing designations do not mean that a
product or brand is not a registered trademark.
SMA Solar Technology AG
Sonnenallee 1
34266 Niestetal
Germany
Tel. [phone]
Fax [phone]
www.SMA.de
Email: [email protected]
Status: 2/28/2019
Copyright © 2019 SMA Solar Technology AG. All rights reserved.

Table of Contents
SMA Solar Technology AG
Operating manual 3MC-BOX-12-3-20-BE-en-13
Table of Contents
1 Information on this Document..................................................................................................... 5
1.1 Validity ............................................................................................................................................................. 5
1.2 Target Group ................................................................................................................................................... 5
1.3 Levels of Warning Messages.......................................................................................................................... 5
1.4 Symbols in the Document................................................................................................................................ 5
1.5 Typographies in the Document....................................................................................................................... 6
1.6 Designation in the document .......................................................................................................................... 6
1.7 Additional Information..................................................................................................................................... 6
2 Safety ............................................................................................................................................ 7
2.1 Intended Use.................................................................................................................................................... 7
2.2 IMPORTANT SAFETY INSTRUCTIONS......................................................................................................... 8
3 Scope of Delivery ......................................................................................................................... 10
4 Product Overview ........................................................................................................................ 11
4.1 Product Description.......................................................................................................................................... 11
4.2 Symbols on the Product................................................................................................................................... 12
4.3 Grounding in the Multicluster System............................................................................................................. 12
4.4 System Structure............................................................................................................................................... 14
5 Mounting....................................................................................................................................... 15
5.1 Requirements for Mounting............................................................................................................................. 15
5.2 Preparing the Mounting Location ................................................................................................................... 16
5.3 Transporting and Mounting the Product ........................................................................................................ 17
6 Electrical Connection .................................................................................................................... 19
6.1 Overview of the Connection Area.................................................................................................................. 19
6.1.1 Interior View ..................................................................................................................................................... 19
6.1.2 View from Below.............................................................................................................................................. 20
6.2 Installing the Multicluster-Box without Grid-Connect-Box or NA-Box........................................................... 21
6.3 Connecting the Generator .............................................................................................................................. 21
6.4 Utility Grid Connection.................................................................................................................................... 22
6.4.1 Utility Grid Connection Options...................................................................................................................... 22
6.4.2 Connecting the NA-Box / Grid-Connect-Box ................................................................................................ 22
6.5 Connecting the Loads...................................................................................................................................... 23
6.6 Connecting the PV System .............................................................................................................................. 24
6.7 Connecting the Sunny Island .......................................................................................................................... 25
6.8 Grounding the Multicluster System................................................................................................................. 25
6.9 Connecting the Control Cables ...................................................................................................................... 26
6.9.1 Assignment of Spring-Cage Terminals ............................................................................................................ 26
6.9.2 Connecting the Control Cables of the Sunny Island Inverters....................................................................... 27
6.9.3 Connecting Supply Voltage for Grounding Contactor.................................................................................. 27
6.9.4 Connecting the Control Cables to the Grid-Connect-Box.............................................................................. 27
6.9.5 Connecting the Control Cables to the NA-Box.............................................................................................. 28
6.10 Connecting the Data Cable............................................................................................................................ 28
7 Preparing for Commissioning ..................................................................................................... 30
8 Disconnect from voltage sources ................................................................................................ 31
9 Periodic Actions ............................................................................................................................ 32

Table of Contents SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-134
9.1 Removing the Protective Cover....................................................................................................................... 32
9.2 Inserting Power and Control Cables .............................................................................................................. 33
9.3 Inserting Data Cables...................................................................................................................................... 34
9.4 Connecting Power Cables to Spring-Cage Terminals................................................................................... 35
9.5 Connecting Control Cables to Spring-Cage Terminals ................................................................................. 36
9.6 Mounting the Protective Cover ....................................................................................................................... 37
10 Maintenance................................................................................................................................. 39
10.1 Inspection of Residual-Current Devices .......................................................................................................... 39
10.2 Checking the Surge Arresters ......................................................................................................................... 40
10.3 General Maintenance Work .......................................................................................................................... 41
11 Decommissioning the Product ..................................................................................................... 43
12 Technical Data .............................................................................................................................. 44
13 Multicluster Technology Terms.................................................................................................... 49
14 Contact .......................................................................................................................................... 51

1 Information on this Document
SMA Solar Technology AG
Operating manual 5MC-BOX-12-3-20-BE-en-13
1 Information on this Document
1.1 Validity
This document is valid for:
• MC-BOX-12.3-20 (Multicluster-Box 12)
1.2 Target Group
The tasks described in this document must only be performed by qualified persons. Qualified persons must have the
following skills:
• Training in how to deal with the dangers and risks associated with installing, repairing and using electrical
devices, batteries and installations
• Training in the installation and commissioning of electrical devices and installations
• Knowledge of all applicable laws, standards and directives
• Knowledge of and compliance with this document and all safety information
1.3 Levels of Warning Messages
The following levels of warning messages may occur when handling the product.
DANGER
Indicates a hazardous situation which, if not avoided, will result in death or serious injury.
WARNING
Indicates a hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION
Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.
NOTICE
Indicates a situation which, if not avoided, can result in property damage.
1.4 Symbols in the Document
Symbol Explanation
Information that is important for a specific topic or goal, but is not safety-relevant
☐
Indicates a requirement for meeting a specific goal
☑
Desired result
✖
A problem that might occur
Example

1 Information on this Document SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-136
1.5 Typographies in the Document
Typography Use Example
bold • Messages
• Terminals
• Elements on a user interface
• Elements to be selected
• Elements to be entered
• Connect the insulated conductors
to the terminals X703:1 to
X703:6.
• Enter 10 in the field Minutes.
>• Connects several elements to be
selected • Select Settings > Date.
[Button]
[Key]
• Button or key to be selected or pressed • Select [Enter].
1.6 Designation in the document
Complete designation Designation in this document
Grid-Connect-Box 12 Grid-Connect-Box
Multicluster-Box 12 Multicluster-Box
NA-Box 12 NA-Box
SunnyIsland 6.0H / 8.0H Sunny Island, battery inverter
1.7 Additional Information
For more information, please go to www.SMA-Solar.com.
Title and information content Type of information
SUNNYISLAND 4.0M / 6.0H / 8.0H Operating manual
NA-BOX 12 Operating manual
GRID-CONNECT-BOX 12 Operating manual

2 Safety
SMA Solar Technology AG
Operating manual 7MC-BOX-12-3-20-BE-en-13
2 Safety
2.1 Intended Use
The Multicluster-Box is the main AC distribution board in a multicluster system. The multicluster system forms an AC grid
and is made up of several three-phase clusters.
The product is not suitable for supplying life-sustaining medical devices. A power outage must not lead to personal
injury.
Do not exceed the maximum AC connection power of the Multicluster-Box. Cables with copper conductors must be
used for the installation.
The generator must always be connected directly to the Multicluster-Box.
The utility grid may only be connected to the terminal provided for the generator on the Multicluster-Box under the
following conditions:
• Connecting the utility grid to the Multicluster-Box must be permitted in accordance with the local standards and
directives.
• Connecting the utility grid to the Multicluster-Box must be agreed with the grid operator.
• No generator may be installed in the multicluster system.
To connect the generator and the utility grid, it is necessary to install either a Grid-Connect-Box or an NA-Box between
the utility grid and the Multicluster-Box.
The Multicluster-Box is designed for connection to TN-S, TN-C-S, and TT systems:
• If the multicluster system is using a generator as grid-forming source, the neutral point of the generator must be
grounded (see Section6.8, page25).
• If the Multicluster-Box is used together with an NABox, the utility grid can be a TN-S, TN-C-S or TT system. No
additional grounding measures are required.
• If the Multicluster-Box is used together with the Grid-Connect-Box, remember that the all-pole disconnection can be
deactivated on the Grid-Connect-Box (see operating manual of the Grid-Connect-Box). If the all-pole
disconnection on the Grid-Connect-Box is deactivated, the utility grid must be configured as a TN-C-S system (see
Section4.3, page12).
• If the utility grid is connected directly to the Multicluster-Box, the neutral point of the utility grid must be grounded
(see Section6.8, page25).
The Multicluster-Box must only be operated in conjunction with Sunny Island 6.0H (SI6.0H-12) or SunnyIsland 8.0H
(S18.0H-12). Always take the maximum AC connection power and the permitted inverter combinations into account.
• Only inverters of the same device type may be installed in a cluster.
• Different clusters may be equipped with inverters of different device types.
In terms of interference immunity, the product is suitable for EMC environment A, and in terms of EMC emissions, it is
suitable for EMC environment B (as per IEC 61439-1:2011).
The product is designed for indoor use only.
Only operate the product at temperatures between −-25°C and +60°C.
The Multicluster-Box is designed for use at altitudes of up to 2300 m above Mean Sea Level. If you would like to use
the Multicluster-Box at altitudes above 2300 m, contact Service (see Section14, page51).
Use this product only in accordance with the information provided in the enclosed documentation and with the locally
applicable laws, regulations, standards and directives. Any other application may cause personal injury or property
damage.
Alterations to the product, e.g. changes or modifications, are only permitted with the express written permission of
SMA Solar Technology AG. Unauthorized alterations will void guarantee and warranty claims and in most cases
terminate the operating license. SMA Solar Technology AG shall not be held liable for any damage caused by such
changes.

2 Safety SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-138
Any use of the product other than that described in the Intended Use section does not qualify as the intended use.
The enclosed documentation is an integral part of this product. Keep the documentation in a convenient, dry place for
future reference and observe all instructions contained therein.
This document does not replace and is not intended to replace any local, state, provincial, federal or national laws,
regulations or codes applicable to the installation, electrical safety and use of the product. SMA Solar Technology AG
assumes no responsibility for the compliance or non-compliance with such laws or codes in connection with the
installation of the product.
The type label must remain permanently attached to the product.
2.2 IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS
This section contains safety information that must be observed at all times when working on or with the product.
The product has been designed and tested in accordance with international safety requirements. As with all electrical
or electronical devices, there are residual risks despite careful construction. To prevent personal injury and property
damage and to ensure long-term operation of the product, read this section carefully and observe all safety
information at all times.
DANGER
Danger to life due to electric shock when live components or cables are touched
High voltages are present in the conductive components or cables of the product. Touching live parts and cables
results in death or lethal injuries due to electric shock.
• Do not touch non-insulated parts or cables.
• Disconnect the product from voltage sources and make sure it cannot be reconnected before working on the
device.
• Only disassemble the protective covers, if the product is disconnected from all voltage sources.
• Wear suitable personal protective equipment for all work on the product.
CAUTION
Risk of injury if the product tips over
The product is heavy and may tip over if not properly fastened to the support surface. This can result in crushing
injuries.
• Upon installation, attach the product to the support surface.
CAUTION
Risk of burns due to hot components
Some components and terminals inside the product can become hot during operation. Touching hot components or
terminals can result in burn injuries.
• Wear suitable personal protective equipment for all work on the product.
• Only operate the product with its protective cover mounted.
• Prior to removing the protective cover, let the product cool down.

2 Safety
SMA Solar Technology AG
Operating manual 9MC-BOX-12-3-20-BE-en-13
NOTICE
Damage to the product due to sand, dust and moisture ingress
Sand, dust and moisture penetration can damage the product and impair its functionality.
• Do not open the product during a dust storm or precipitation.
• Close the product in case of interruption of work or after finishing work.
• The product must only be closed during operation.
• Store the product in a dry and covered location when closed. Observe storage conditions.
Effects of an emergency disconnection
Emergency disconnection on the battery inverter triggers the uncontrolled shutdown of the system and unsaved
data is lost.
• Only trip the emergency disconnection to avoid danger or consequential damage.
• In the event of an emergency disconnection, always check whether any fuse elements in the product, such as
circuit breakers, have tripped.
• If any fuse elements have tripped, reactivate these fuse elements.

3 Scope of Delivery SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-1310
3 Scope of Delivery
Check the scope of delivery for completeness and any externally visible damage. Contact your distributor if the scope
of delivery is incomplete or damaged.
B DC
Main Cluster Box
Master
Main Cluster Box
Slave 1
Main Cluster Box
Slave 2
FJ
SMA
A
H
G
E
I
Figure 1: Components included in the scope of delivery
Position Quantity Designation
A 1 Multicluster-Box
B 1 Data cable for communication (10m, black)
C 3 Data cable for measurement and control signals (10m, red)
D 20 Strain relief with counter-sleeve (22mmto28mm)
E 3 LV/HRC size 1 fuse link, 200 A
F 1 Set of non-woven adhesive labels for cable designation
G 4 Terminal incl. screws for connecting the protective conductors
H 3 Fuse link 1A, tripping characteristics: gG
I 1 Fuse link 6A, tripping characteristics: gG
J 1 Operating manual and circuitry overview

4 Product Overview
SMA Solar Technology AG
Operating manual 11MC-BOX-12-3-20-BE-en-13
4 Product Overview
4.1 Product Description
The Multicluster-Box is an SMA multicluster technology device for off-grid systems, battery-backup systems, and systems
for increased self-consumption. The Multicluster-Box is a main AC distribution board to which you can connect up to
four clusters. Each three-phase cluster is made up of three DC-side, parallel-switched SunnyIsland 6.0H / 8.0H
inverters with firmware version 3.5 or higher. Functions of the Multicluster-Box include:
• Main AC distribution board for Sunny Island inverters, one generator, one load, and one PV system
• Load shedding
• Automatic bypass and reverse current monitoring for the generator
• Active anti-islanding
A
A
C
D
B
Figure 2: Multicluster-Box with cabinet door open
Position Designation
A Protective cover
Prevents inadvertent contact with live components during operation and thus protects
from electric shocks. When the product is in operation, the protective covers must al-
ways be mounted.
B Type label
The type label clearly identifies the product. The type label must remain permanently at-
tached to the product. You will find the following information on the type label:
• Device type (Model)
• Serial number (Serial No. or S/N)
• Date of manufacture
• Device-specific characteristics

4 Product Overview SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-1312
Position Designation
C Residual-current device
Protects against electric shock and is always used in addition to existing protective
measures such as insulation or protective grounding. As soon as a dangerous touch
voltage occurs, the residual-current device switches the loads off at all poles. This is
achieved by means of a summation current transformer in the residual-current device
which detects the electric currents in the conductors L1, L2, L3, and N. In the normal
operating state, the sum of these currents equals zero. Under fault conditions a differen-
tial current is formed which trips the residual-current device.
The residual-current device has a test button and a switch lever. The test button is used
to test the residual-current device. The switch lever is used to activate and deactivate
(see Section10.1, page39).
D Circuit breaker
Protects power cables of the connected inverters.
4.2 Symbols on the Product
Symbol Explanation
Beware of electrical voltage
The product operates at high voltages.
Beware of hot surface
The product can get hot during operation.
Observe the documentation
Observe all documentation supplied with the product.
Grounding conductor
This symbol indicates the position for connecting a grounding conductor.
WEEE designation
Do not dispose of the product together with the household waste but in accordance with the
disposal regulations for electronic waste applicable at the installation site.
Degree of protectionIP55
The product is protected against interior dust deposits and water that is directed as a jet
against the enclosure from all directions.
CE marking
The product complies with the requirements of the applicable EU directives.
4.3 Grounding in the Multicluster System
Grounding in the Multicluster-Box
The grounding busbar X100 of the Multicluster-Box is always connected to the enclosure of the Multicluster-Box.
All grounding conductors must be connected in accordance with the specifications of this operating manual (see
Section6, page19).

4 Product Overview
SMA Solar Technology AG
Operating manual 13MC-BOX-12-3-20-BE-en-13
With TN-S, TN-C-S, and TT systems, the neutral conductor must be grounded for protection against indirect contact with
live components. The following conditions apply to grounding the neutral conductor in the multicluster system:
• If the multicluster system is using a generator as grid-forming source, the neutral point of the generator must be
grounded.
• If the multicluster system is connected to the utility grid via NA-Box or Grid-Connect-Box, the neutral point is
grounded via the utility grid when in parallel grid operation. However, in case of grid failure, the multicluster
system must disconnect from the utility grid. For this disconnection, either only the line conductors are
disconnected, or in case of all-pole disconnection, the line conductors and the neutral conductor.
• If the utility grid is connected directly to the Multicluster-Box, the neutral point of the utility grid must be grounded.
The installer bears sole responsibility for the grounding configuration and the grid disconnection required for
instances of grid failure. Directly connecting the utility grid to the Multicluster-Box must be permitted in accordance
with the local standards and directives and agreed with the grid operator.
With all-pole disconnection, the multicluster system with line conductors and neutral conductor are disconnected from
the utility grid in the event of grid failure. This disconnection does not ground the neutral conductor in the grid of the
multicluster system. Therefore, in multicluster systems with all-pole disconnection, the grounding contactor of the
Multicluster-Box must ground the neutral conductor in the event of grid failure. The grounding contactor ensures the
necessary protection in case of indirect contact with live components. The grounding contactor is in fail-safe design.
If the neutral conductor of the multicluster system is connected to the utility grid, no further grounding is permitted in the
electricity grid of the multicluster system. Therefore, if the multicluster system is connected to the utility grid or generator,
the grounding contactor of the Multicluster-Box breaks the connection between neutral conductor and ground
potential.

4 Product Overview SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-1314
4.4 System Structure
SUNNY ISLAND
NA BOX /
GRID CONNECT
BOX
Load contactor
MULTICLUSTER BOX
(Main AC distribution board)
PV main
distribution box
(not included in the
delivery)
BATTERY
Generator contactor GENERATOR
LOAD
PV MODULES
PV INVERTERS
UTILITY GRID
BATTERY FUSE
Figure 3: Circuitry principle of a multicluster system – example with Multicluster-Box

5 Mounting
SMA Solar Technology AG
Operating manual 15MC-BOX-12-3-20-BE-en-13
5 Mounting
5.1 Requirements for Mounting
WARNING
Danger to life due to fire or explosion
Despite careful construction, electrical devices can cause fires.
• Do not mount the product in areas containing highly flammable materials or gases.
• Do not mount the product in potentially explosive atmospheres.
Optimum mounting location
The ambient temperature influences the tripping threshold of the circuit breakers for the connected battery
inverters. The higher the temperature, the earlier the circuit breakers will trip. At high ambient temperatures, the
derating function of the battery inverters inhibits premature tripping of the circuit breakers.
• To ensure optimum operation, mount and install the Multicluster-Box and the battery inverters at the same
location.
Mounting location:
☐ A solid, flat support surface must be available for mounting.
☐ The mounting location must be suitable for the weight and dimensions of the product (see Section12 "Technical
Data", page44).
☐ The mounting location should be freely and safely accessible at all times without the need for any auxiliary
equipment (such as scaffolding or lifting platforms). Non-fulfillment of these criteria may restrict servicing.
☐ The mounting location must not hinder access to disconnection devices.
☐ All local requirements concerning minimum passage widths and escape routes must be observed.
☐ All ambient conditions must be met (see Section12, page44).
☐ The mounting location must be less than 2300 m above Mean Sea Level. If you would like to use the Multicluster-
Box at altitudes above 2300 m, contact Service (see Section14, page51).
☐ The product may only be mounted in a permitted mounting position.
Permitted und prohibited mounting position:
Figure 4: Permitted and prohibited mounting positions

5 Mounting SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-1316
Recommended clearances:
200200200
Figure 5: Recommended clearances (dimensions in mm)
☐ There must be sufficient space at the mounting location to ensure compliance with the recommended clearances.
☐ There must be a distance of at least 300mm between the Multicluster-Box and the Grid-Connect-Box or NA-Box.
This will ensure adequate heat dissipation for each product.
Dimensions for mounting:
300
1200
Ø 13
980
1075 62.5
26360
Figure 6: Outside base measurements and dimensions of the drill holes (dimensions in mm)
5.2 Preparing the Mounting Location
WARNING
Danger to life due to fire or explosion if mounted at an unsuitable location
Mounting the product in areas with a high fire hazard can result in fire. This can result in death or serious injury.
• Do not install the product on flammable construction materials.
• Do not mount the product in areas containing highly flammable materials.
• Do not mount the product in potentially explosive atmospheres.
Additionally required mounting material (not included in the scope of delivery):
☐ 4 suitable screw anchors for attaching the product
Procedure:
1. On the support surface, mark the positions of the four drill holes for attaching the base (see Section5.1,
page15).
2. Drill holes at the marked positions.
3. Use screw anchors that are suitable for the support surface.

5 Mounting
SMA Solar Technology AG
Operating manual 17MC-BOX-12-3-20-BE-en-13
5.3 Transporting and Mounting the Product
WARNING
Danger to life if raised or suspended loads tip over, fall or sway
Vibrations or careless or hasty lifting and transportation may cause the product to tip over or fall. This can result in
death or serious injury.
• Always transport the product as close to the floor as possible.
• All means of transport and auxiliary equipment used must be designed for the weight of the product. Weight:
228 kg.
• Always transport and lift the product upright.
• Always maintain a sufficient safety distance from the product during transport.
• Take into account the center of gravity of the product. The center of gravity is approximately in the center of the
cabinet.
• Wear suitable personal protective equipment for all work on the product.
NOTICE
Damage to the product due to sand, dust and moisture ingress after setting down on
unsuitable surface
Setting the product down on an unsecured or uneven surface may cause the product to warp and allow sand, dust
and moisture to enter the product. Sand, dust and moisture penetration can damage the product and impair its
functionality.
• Never set the product down on an unsecured or uneven surface.
Overview of transport options:
The product is delivered on a Euro pallet. You can use the following means of transport to lift the product off the Euro
pallet:
• Forklift
• Crane with suitable fork
Additionally required mounting material (not included in the scope of delivery):
☐ 4 suitable screws to attach the product to the support surface
Procedure:
1. Remove all fastening screws from the kick plates at the front and rear (TX30).
2. Remove kick plates.
3. Retain the kick plates and the fastening screws for later use.
4. Slide a suitable means of transport under the product.
5. Transport the product to the mounting location using a suitable transport lock.

5 Mounting SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-1318
6. CAUTION
Risk of injury if the Multicluster-Box tips over
The Multicluster-Box is heavy and may tip over if not properly fastened to the support surface. This can result in
crushing injuries.
• Attach the product to the support surface using four suitable screws.

6 Electrical Connection
SMA Solar Technology AG
Operating manual 19MC-BOX-12-3-20-BE-en-13
6 Electrical Connection
6.1 Overview of the Connection Area
6.1.1 Interior View
KL
M
N
AB
D
F
H
I
J
O
P
E
G
C
Figure 7: Components and terminals inside the Multicluster-Box
Position Designation
AFuse switch-disconnector F101 for LV/HRC size 1 fuse links of the generator terminal
BFuse switch-disconnector F102 for LV/HRC size 1 fuse links of the load terminal
C Surge arrester
D Residual-current device of the SunnyIsland inverters
E Circuit breakers for protecting the power cables of the SunnyIsland inverters
FSpring-cage terminals X105 for connecting the power cables of the SunnyIsland inverters
G Grounding contactor

6 Electrical Connection SMA Solar Technology AG
Operating manualMC-BOX-12-3-20-BE-en-1320
Position Designation
HSpring-cage terminals X106 to X113 for connecting the control cables of the SunnyIsland invert-
ers, battery fuse, Grid-Connect-Box or NA-Box
IGrounding busbar X100 for connecting the grounding conductors of the generator, the loads, and
the PV system as well as to connect the Multicluster-Box to the equipotential bonding
If a Grid-Connect-Box or NA-Box is installed, the corresponding grounding conductor is also con-
nected here.
When connecting the utility grid directly to the Multicluster-Box, the grounding conductor is also
connected here (see Section6.4.1, page22).
J Cable support rail
KTerminal X104 with spring-cage terminals L1, L2, L3 and N to connect the line conductors and the
neutral conductor of the PV system
LTerminal X103 with spring-cage terminals L1, L2, L3 and N to connect the line conductors and the
neutral conductor of the main distribution for loads
MTerminal X102 with spring-cage terminals L1, L2, L3 and N to connect the line conductors and the
neutral conductor of the generator
When connecting the utility grid directly to the Multicluster-Box, the line conductors are also con-
nected here (see Section6.4.1, page22).
NTerminal X101 with spring-cage terminals L1, L2, L3 and N to connect the line conductors and the
neutral conductor of the Grid-Connect-Box or NA-Box
If only the Multicluster-Box is installed, these terminals are not connected.
OSIBUCTRL with RJ45 jacks for connecting the data cables
P Fuses to protect the internal cabling
6.1.2 View from Below
B
A
Figure 8: Enclosure openings in the bottom of the Multicluster-Box
Position Designation
A Base plate with membranes for inserting the power cables
B Two-part cable feed-through for inserting the data cables