SMA SUNNY CENTRAL STRING-MONITOR US Parts list manual

SSMUS-TUS094511 | 98-4001411 | Version 1.1 US
Sunny Central Accessories
SUNNY CENTRAL STRING-MONITOR US
Technical Description

SMA Solar Technology AG
Technical Description SSMUS-TUS094511 3
Copyright © 2009 SMA America, Inc. All rights reserved.
No part of this document may be reproduced, stored in a retrieval system, or transmitted, in any form
or by any means, electronic, mechanical, photographic, magnetic or otherwise, without the prior
written permission of SMA America, Inc.
SMA America makes no representations, 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 warranties are
expressly disclaimed. Neither SMA America 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 SMA America
reserves the right to make changes without notice and 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 America, Incorporated
4031 Alvis Court
Rocklin, California 95677-4011
Tel [phone]
Fax [phone]
www.sma-america.com

SMA Solar Technology AG
4SSMUS-TUS094511 Technical Description
IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS
This manual contains important instructions for Models Sunny Central String-Monitor U DC
COMBINER BOX, that shall be followed during installation and maintenance of the DC combiner
box.
The Sunny Central String-Monitor is designed and tested according to international safety
requirements, but as with all electrical and electronic equipment, certain precautions must be
observed when installing and/or operating the Sunny Central String-Monitor. To reduce the risk of
personal injury and to ensure the safe installation and operation of the Sunny Central String-Monitor,
you must carefully read and follow all instructions, cautions and warnings in this Installation Guide.
Warnings
A Warning describes a hazard to equipment or personnel. It calls attention to a procedure or
practice, which, if not correctly performed or adhered to, could result in damage to or destruction of
part or all of the SMA equipment and/or other equipment connected to the SMA equipment or
personal injury.
DANGER
DANGER indicates a hazardous situation which, if not avoided, will result in death or
serious injury.
WARNING
WARNING indicates a hazardous situation which, if not avoided, could result in death or
serious injury.
CAUTION
CAUTION indicates a hazardous situation which, if not avoided, could result in minor or
moderate injury.
NOTICE
NOTICE indicates a situation that can result in property damage if not avoided.

SMA Solar Technology AG
Technical Description SSMUS-TUS094511 5
Other Symbols
In addition to the safety and hazard symbols described on the previous pages, the following symbol
is also used in this Installation Guide:
Markings on this Product
The following symbols are used as markings on this product with the following meanings.
Information
This symbol accompanies notes that call attention to supplementary information that you
should know and use to ensure optimal operation of the system.
Warning regarding dangerous voltage
The product works with high voltages. All work on the product may only be done as
described in its documentation.
Beware of hot surface
The product can become hot during operation. Avoid coming into contact with the
product during operation.
Observe the operating instructions
Read the product’s documentation before working on it. Follow all safety
precautions and instructions as described in the documentation.
DC current
Earth Ground

SMA Solar Technology AG
6SSMUS-TUS094511 Technical Description
General Warnings
General Warnings
All electrical installations must be done in accordance with the local and National Electrical
Code ANSI/NFPA 70. In Canada, wiring methods shall be per the Canadian Electrical
Code Part II.
The Sunny Central String-Monitor contains no user-serviceable parts. For all repair and
maintenance always contact an authorized SMA Service Center.
Before installing or using the Sunny Central String-Monitor, read all of the instructions,
cautions, and warnings on the Sunny Central String-Monitor, the PV array, in this
Installation Guide and in User Manual.
PV arrays produce electrical energy when exposed to light and thus can create an
electrical shock hazard. Wiring of the PV-arrays shall only be performed by qualified
personnel.
This product is intended for operation in an environment having a maximum ambient
temperature of 113 °F (45 °C).
The DC ouput terminals shall be connected using the following wire types: Copper an
copper clad conductors only - use No. 350 kcmil, copper wire.
The DC input wires (Fuse holder)shall be connected using the following wire types: Rigid
wire 10 - 6 AWG; Multistrand wire: 10 - 8 AWG.
The Input wire (Busbar) shall be connected using the following wire types: 10 - 4 AWG

SMA Solar Technology AG Table of Contents
Technical Description SSMUS-TUS094511 7
Table of Contents
1 About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.1 Target Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2 Area of Validity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1 Appropriate Usage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2 Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3 Unpacking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 Unpacking and Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 Packing List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3 Identifying the Sunny Central String-Monitor . . . . . . . . . . . . . . 16
4 Mounting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1 Selection of Mounting Location . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1.1 Ambient Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1.2 Dimensions and Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1.3 Minimum Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.1.4 Permissible Slanting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.1.5 Mounting to PV Module Racks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2 Mounting to a Pole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.2.1 Mounting the Sunny Central String-Monitor to a pole (square) . . . . . . . . . . 20
4.2.2 Mounting the Sunny Central String-Monitor to a pole (round) . . . . . . . . . . . 22
4.3 Mounting to a Wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.3.1 Mounting the Sunny Central String-Monitor to a wall. . . . . . . . . . . . . . . . . . 26
5 Attaching the Cable Conduits . . . . . . . . . . . . . . . . . . . . . . 28
6 Communication connector. . . . . . . . . . . . . . . . . . . . . . . . . 29
6.1 Preparing the Data Cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.2 Communication Connector Sunny Central String-Monitor . . . . 32

Table of Contents SMA Solar Technology AG
8SSMUS-TUS094511 Technical Description
6.2.1 Connecting the Data Cable in the Sunny Central String-Monitor . . . . . . . . . 33
6.2.2 Grounding the Shield of the Data Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
6.2.3 Terminate the RS485 bus in the Sunny Central String-Monitor . . . . . . . . . . . 34
6.3 Communication Connector Sunny Central . . . . . . . . . . . . . . . . 35
6.3.1 Connecting the Data Cable in the Sunny Central . . . . . . . . . . . . . . . . . . . . . 35
6.3.2 Grounding the Shield of the Data Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
7 Electrical Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.1 Connection area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.2 Connecting ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.2.1 PV modules: Connecting ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
7.2.2 Sunny Central: Connecting ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
7.3 Connecting PV modules - negative grounding . . . . . . . . . . . . . 41
7.3.1 PV modules: Connecting DC–. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
7.3.2 PV modules: Connecting DC+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
7.4 Connecting the PV modules - positive grounding . . . . . . . . . . . 44
7.4.1 PV modules: Connecting DC+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
7.4.2 PV modules: Connecting DC–. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
7.5 Connecting Sunny Central - negative grounding . . . . . . . . . . . 47
7.5.1 Sunny Central: Connecting DC–. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
7.5.2 Sunny Central: Connecting DC+. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
7.6 Connecting Sunny Central - positive grounding . . . . . . . . . . . . 50
7.6.1 Sunny Central: Connecting DC+. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
7.6.2 Sunny Central: Connecting DC–. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9 Maintenance and Cleaning. . . . . . . . . . . . . . . . . . . . . . . . 54
9.1 Replace fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.1.1 Replace string fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.1.2 Replace Fuse from Electronic Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
10 Opening and Closing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

SMA Solar Technology AG
Technical Description SSMUS-TUS094511 9
10.1 Opening Sunny Central String-Monitor . . . . . . . . . . . . . . . . . . 58
10.2 Closing the Sunny Central String-Monitor. . . . . . . . . . . . . . . . . 59
11 Operation of the Sunny Central String-Monitor . . . . . . . 60
11.1 Terms and Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
11.2 Communication Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
11.2.1 Status Display Sunny Central String-Monitor . . . . . . . . . . . . . . . . . . . . . . . . 62
11.2.2 Status Display Sunny Central String-Monitor Controller . . . . . . . . . . . . . . . . 63
11.3 Spot Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
11.3.1 Spot values Sunny Central String-Monitor Controller . . . . . . . . . . . . . . . . . . 64
11.3.2 Spot values Sunny Central String-Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . 65
11.4 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
11.4.1 Parameters for Sunny Central String-Monitor Controller. . . . . . . . . . . . . . . . 66
11.4.2 Parameters for Sunny Central String-Monitor . . . . . . . . . . . . . . . . . . . . . . . . 69
11.5 Setting the PV Plant Monitoring System . . . . . . . . . . . . . . . . . . 70
11.6 Optional Settings for the PV plant Monitoring System . . . . . . . 72
11.6.1 Setting the communication period of Sunny Central String-Monitors . . . . . . 72
11.6.2 Setting the monitoring period of Sunny Central String-Monitors . . . . . . . . . . 72
11.6.3 Allocation of PV strings to groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
12 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
12.1 Detection and Elimination of Faults. . . . . . . . . . . . . . . . . . . . . . 74
12.1.1 Detecting errors with the Sunny Central String-Monitor Controller . . . . . . . . 74
12.1.2 Detecting errors with the Sunny Central String-Monitor . . . . . . . . . . . . . . . . 75
12.2 Confirm warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
13 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
13.1 Torques and Cable sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
13.1.1 Negative Grounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
13.1.2 Positive grounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
14 Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

SMA Solar Technology AG
10 SSMUS-TUS094511 Technical Description

SMA Solar Technology AG About this Manual
Technical Description SSMUS-TUS094511 11
1 About this Manual
The manual describes how to install and commission the Sunny Central String-Monitor US. For the
purposes of this manual, the Sunny Central String-Monitor US is referred to as Sunny Central String-
Monitor.
1.1 Target Group
This manual is for qualified personnel. Qualified personnel has received training and has
demonstrated skills and knowledge in the construction and operation of the device. Qualified
personnel is trained to deal with the dangers and hazards involved in installing electric devices.
1.2 Area of Validity
This manual is valid for the Sunny Central String-Monitor US starting with fabrication version A. The
Sunny Central String-Monitor US will be referred to as Sunny Central String-Monitor in this manual.
This manual does not cover any details concerning PV modules. Information concerning the PV
modules is available from the manufacturer of the PV modules.

Security SMA Solar Technology AG
12 SSMUS-TUS094511 Technical Description
2 Security
2.1 Appropriate Usage
The Sunny Central String-Monitor is a Smart-Combiner. Depending on the versions, the box provides
the possibility to directly connect 24, 32 or 64 strings and to link them with the Sunny Central inverter.
All inputs are fused in compliance with NEC.
Additionally, a high-resolution string monitoring is integrated in the device. It permanently measures
and monitors the string current of all inputs and detects partial and total dropouts. In case of failures
and dropouts, the responsible person is immediately informed via the WebBox.
Principle of a PV Power System with Sunny Central String-Monitor
Any other application of the Sunny Central String-Monitor, installation of components and
modifications, that are not explicitly allowed, endanger the safety and void the warranty as well as
the operation permission.
Position Description
APV modules
B Sunny Central String-Monitor
CDC disconnect
DSunny Central
EAC fuse
F AC disconnect
GPublic grid
AB
CD F
G
E
StopStart

SMA Solar Technology AG Security
Technical Description SSMUS-TUS094511 13
It is prohibited:
• to use the Sunny Central String-Monitor for purposes other than those indicated in this
installation guide,
• to connect voltage sources to the Sunny Central String-Monitor other than those consisting of PV
modules,
• to modify the Sunny Central String-Monitor or to install components that are not explicitly
recommended by SMA or sold by SMA for this purpose!
2.2 Safety Precautions
DANGER
Improper performance of the tasks described in this manual.
Death or serious injuries.
• All work on the Sunny Central String-Monitor must only be carried out by a qualified
personnel.
• All work on the Sunny Central String-Monitor may only be done as described in this
manual.
• Pay attention to all safety precautions.
WARNING
Risk of electric shock during operation of a damaged Sunny Central String-Monitor.
Death or serious injuries.
• The Sunny Central String-Monitor may only be used when it is technically faultless
and safe to operate!
• Operate the Sunny Central String-Monitor only if no damage is visibly evident!
• Visually check the Sunny Central String-Monitor for damage on a regular basis!
• Ensure that all external safety features are freely accessible at all times, and that they
are regularly tested for correct functionality!

Security SMA Solar Technology AG
14 SSMUS-TUS094511 Technical Description
NOTICE
Electrostatic discharges possible when components are touched.
Damage to components.
• Follow ESD protective provisions.
• Remove existing electrostatic charges by touching a grounded metal surface (e.g.
housing).
Storage of the Documentation
The documentation must be kept in the immediate vicinity of the Sunny Central String-
Monitor. They must be available to operators and maintenance staff at all times.

SMA Solar Technology AG Unpacking
Technical Description SSMUS-TUS094511 15
3 Unpacking
3.1 Unpacking and Inspection
All SMA Sunny Central String-Monitors are thoroughly checked before they are packaged and
shipped. Although they are shipped in sturdy packaging, damage can still occur during shipping and
delivery. It is important to carefully inspect the shipping container and contents prior to installation. If
you detect any external damage after unpacking, report the damage immediately to your SMA
dealer and to the shipping company that delivered the unit. If it becomes necessary to return the Sunny
Central String-Monitor USA, use the original packing material.
If you need assistance with a damaged Sunny Central String-Monitor, contact your SMA dealer or
SMA America. Contact information for SMA America is provided in chapter 14 "Contact"
(page80).
3.2 Packing List
Position Description
A Sunny Central String-Monitor US (left: version 24 and 32, right: version 64)
B Installation kit for pole mounting
C Installation kit for wall mounting
D Installation Guide: mounting and installation of the Sunny Central String-Monitor
Circuit Diagrams: circuit diagrams of the Sunny Central String-Monitor
E 2x plug for communication cable
F Termination resistor plug
Gewährleistungs-undGarantiebedingungen
(NamedesGerätes):
Bitte füllenSie die folgendenFelderaus:
:
Typ:
Seriennummer:
DatumderInbetriebnahme:
Anschrift:
Installationsbetrieb
Typ:
Seriennummer:
DatumderInbetriebnahme:
Anschrift:
Installationsbetrieb
SI5048-11:ED4206
TB-SI5048
Su n n y B o y SB4000TL/ 5000TL
WechselrichterfürSolarstromanlagen
TechnischeBeschreibungAu
sgabe1.0
SI5048-11:ED4206
TB-SI5048
Su n n y B o y SB4000TL/ 5000TL
Wechselrichterfür Solarstromanlagen
TechnischeBeschreibungAu
sgabe1.0
ABC
DEF

Unpacking SMA Solar Technology AG
16 SSMUS-TUS094511 Technical Description
3.3 Identifying the Sunny Central String-Monitor
The Sunny Central String-Monitor can be identified with
the type label (see image on the right). The type label is
located on the inside of the Sunny Central String-Monitor
door.
Specified on the type plate:
Position Name Description
A Model The Sunny Central String-
Monitor type name with
version code (optional).
B Serial No. Serial number of the Sunny
Central String-Monitor.
C Manufacturing
Version
Manufacturing version of
the Sunny Central String-
Monitor.
SMA Solar Technology AG
www.SMA.de
SUNNY CENTRAL
String-Monitor US
Model Serial No.
SSM-US: 20 107
Fabrication Version: P02
Fabrication Date: 09/2009
This unit approved for use in DC circuits only
Max. system voltage under all conditions 600V DC
Operating voltage range (Vdc)* 0 - 600 V DC
Max. string current * 5.1A DC
Max. continuous current* 328 A DC
Max. operating current* 480 A DC
Short circuit rating* 512 A DC
Operating temperature range*
-13°F to +122°F (-25°C to +45°C)
Enclosure: Type 4R (IP54)
* For more details and for tightening torque, allowable wire
size and type see the Operator‘s Manual
PV Array Combiner
LISTED UL 1741
A
B
C

SMA Solar Technology AG Mounting
Technical Description SSMUS-TUS094511 17
4 Mounting
This section provides guidelines to help you select the best mounting location, suggestions to insure
optimum performance, cautions and warnings that you should follow to avoid injury and/or
equipment damage, and step-by-step instructions for mounting a Sunny Central String-Monitor.
4.1 Selection of Mounting Location
4.1.1 Ambient Conditions
• The installation method and mounting location must be suitable for the weight and dimensions.
• Mounting on a solid surface.
• The mounting location must be accessible at all times.
• The ambient temperature must be between -13 ... 113 °F (-25 °C and +45 °C).
• Do not mount the Sunny Central String-Monitor in a location where it is exposed to direct
sunlight.
CAUTION
Risk of injury during transport of the Sunny Central String-Monitor.
Injuries and contusion of body parts.
• Transport the Sunny Central String-Monitor with two people or with a cart.
• Wear personal protective equipment.

Mounting SMA Solar Technology AG
18 SSMUS-TUS094511 Technical Description
4.1.2 Dimensions and Weight
The Sunny Central String-Monitor version 24 weighs 143 lbs. (65 kg) version 32 weighs 146 lbs. (66
kg), version 64 weighs 194 lbs. (88 kg). The mounting location must be suitable for the weight of the
Sunny Central String-Monitor. The Sunny Central String-Monitor may not be mounted to plasterboard
walls or similar.
4.1.3 Minimum Clearance
Keep a clearance of at least 60 in. (1,500 mm) to walls, other devices or similar. This clearance is
necessary in order to allow to insert the cables to the Sunny Central String-Monitor and open the
Sunny Central String-Monitor.
Clearances
The National Electrical Code may require significantly larger working clearances (see
NEC Section 110.26).
32.87 in (835 mm)
48.62 in (1235 mm)
31.5 in
(800 mm)
31.5 in
(800 mm)
9.84 in
(250 mm)
11.81 in
(300 mm)

SMA Solar Technology AG Mounting
Technical Description SSMUS-TUS094511 19
4.1.4 Permissible Slanting
The Sunny Central String-Monitor must be mounted vertically.
• Never install the device with a backward tilt.
• Never install the device with a forward tilt.
• Do not install horizontally.
4.1.5 Mounting to PV Module Racks
The Sunny Central String-Monitor can be mounted to the back of module racks. It is not permitted to
be mounted in a location where rainwater will flow over the Sunny Central String-Monitor. The image
below schematically illustrates how the Sunny Central String-Monitor can be mounted to a PV module
rack.

Mounting SMA Solar Technology AG
20 SSMUS-TUS094511 Technical Description
4.2 Mounting to a Pole
4.2.1 Mounting the Sunny Central String-Monitor to a pole
(square)
The Sunny Central String-Monitor can be mounted to a square or round pole. An installation kit for
pole mounting is included in the Sunny Central String-Monitor accessories kit. This section describes
mounting to a square pole.
Two mounting rails are attached to the rear side of the
Sunny Central String-Monitor. In the middle of the
mounting rails there are 2 internal threads for attaching
the pole mount.
APole mount
B Threaded bolt
CNuts
DWashers
Dimensions of the square pole
The Sunny Central String-Monitor can be mounted on square poles with the following
dimensions:
• minimum: 3.94 in. (100 mm)
• maximum: 7.48 in. (190 mm)
AB
C
D