SMA SWR 2500U - V1.2 Setup guide

SB2500U-11:NE3801
Grid Tied String Inverter for Photovoltaic Systems
Issue 1.2
Installation and Operator’s Manual
Sunny Boy
SWR 2500U

Sunny Boy 2500U Installation and Operator’s Manual
SB2500U-11:NE - 2- SMA Regelsysteme GmbH

Sunny Boy 2500U Installation and Operator’s Manual
SB2500U-11:NE - 3- SMA Regelsysteme GmbH
IMPORTANT SAFETY INSTRUCTIONS
This manual contains important instructions that shall be followed during in-
stallation and maintenance of the Sunny Boy.
To reduce the risk of electrical shock, and to ensure the safe installation and
operation of the Sunny Boy, the following safety symbols have been placed
throughout this technical description to indicate dangerous conditions and im-
portant safety instructions.
WARNING: This indicates a fact or feature very important for the safety of
the user and / or which can cause a serious hardware defect if not applied
appropriately.
Use extreme caution when performing this task.
NOTE: This indicates a feature that is important either for optimal and
comfortable usage or optimal operation of the system.
Follow instructions closely.
EXAMPLE: This indicates an example.
SAVE THESE INSTRUCTIONS

Sunny Boy 2500U Installation and Operator’s Manual
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IMPORTANT SAFETY INSTRUCTIONS
• All electrical installations shall be done in accordance with the local and
national electrical codes ANSI/NFPA 70.
• The Sunny Boy contains no user serviceable parts. Please return the unit
to an SMA authorized Service Center (see page 56) for maintenance.
• Before installing or using the Sunny Boy, please read all instructions and
cautionary markings in the technical description and on the Sunny Boy
and the PV-array.
• Connecting the Sunny Boy to the electrical utility grid must only be done
after receiving prior approval from the utility company and performed only
by qualified personnel.
• Completely cover the surface of all PV-arrays with opaque (dark) material
before wiring them. PV arrays produce electrical energy when exposed to
light and could create a hazardous condition.
• On top of the device you can find the heat sink of the Sunny Boy with
potential temperatures of over 175°F (80 °C). To reduce the risk of burns,
do not touch.
SAVE THESE INSTRUCTIONS

Sunny Boy 2500U Installation and Operator’s Manual
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Table of Contents
1Introduction ...............................................................................................................6
2Installation.................................................................................................................7
2.1 What Must Be Done in Case of Transport Damages?......................................7
2.2 Placement of the Sunny Boy ............................................................................8
2.3 Electric Connection.........................................................................................12
2.3.1 Preparation of the electric connection........................................................14
2.3.2 Connection to Electrical Utility Grid............................................................16
3Commissioning........................................................................................................20
4Operation and Failure Indication LEDs ...................................................................24
4.1 Operation Indicator .........................................................................................27
4.2 Ground Fault Indicator....................................................................................30
4.3 Failure Indication ............................................................................................31
4.4 Opening and closing of the Sunny Boy...........................................................36
4.5 Upgrading or modification of the Sunny Boy interface....................................39
4.6 Measuring Channels and Messages...............................................................41
4.7 Measurement Precision..................................................................................43
5Troubleshooting ......................................................................................................44
6Warranty Regulations and Liability..........................................................................46
7Technical Data ........................................................................................................48
7.1.1 Minimum MPP-voltage of the PV panel......................................................49
8Appendix .................................................................................................................56

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1 Introduction
The SMA Sunny Boy is a string inverter for grid tied operation. With this manual the
Sunny Boy can be installed and operated in a safe way. This installer’s guide is used
as reference for the commissioning and as guideline on how to use all functions of
the inverter optimally and how you can extend your existing PV-plant.
Supplementary grid feeding includes the conversion of the DC-voltage from the PV-
panel to grid compatible AC-voltage with so-called ”inverters“ and the subsequent
connection to the electricity grid in the house distribution.
Here the electricity from the PV-modules provides all consumers with electric power
(household devices, lights etc.). In case that not enough power is produced the addi-
tionally necessary power is obtained from the grid. In case that there is a surplus of
power, this surplus is fed into the local grid and is therefore available for other con-
sumers. This way every single kilowatt-hour is utilized and the electricity company’s
power systems are relieved. In the most simple case a PV-plant therefore consists of
two basic components: the PV-panel and the inverter.
Fig. 1.1: Grid tied string inverter application
For a more detailed technical description of the Sunny Boy and its functionality
please read “Sunny Boy 2500U Technical Description”.

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2 Installation
WARNING: Before installing the Sunny Boy, read all instructions and cau-
tionary markings in the technical description and on the Sunny Boy and
the photovoltaic array.
WARNING: All electrical installations shall be done in accordance with all
local electrical codes and the National Electrical Code (NEC),
ANSI/NFPA 70.
WARNING: Connecting the Sunny Boy to the electrical utility grid must
only be done after receiving prior approval from the utility company and
performed only by qualified personnel.
2.1 What Must Be Done in Case of Transport Damages?
The Sunny Boy inverters are thoroughly checked before they are shipped. Even
though they are delivered in a sturdy packaging (which can be recycled) the inverters
can be damaged which is the forwarding company’s fault in most cases.
Please inspect your inverter thoroughly after it is delivered. If any damages can be
detected on the packaging that could lead to the conclusion that the contents is dam-
aged or if you detect that the inverter is damaged please immediately notify the for-
warding company.
SMA or your local supplier can help you in this matter. In any case the declaration of
transport damage must be made within 6 days upon receipt of the product and must
be stated in writing directly to the forwarding agent. If it is necessary to return the in-
verter to the manufacturer please use the packaging the inverter was sent in.

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2.2 Placement of the Sunny Boy
The Sunny Boy is a sophisticated electronic device and is therefore sensitive to hu-
midity within the case.
NOTE: If the Sunny Boy is placed outside, the humidity during the installa-
tion should be as low as possible - pay special attention that it does not
rain. If moisture is enclosed in the case it will eventually condense within
the device which could damage the electronics.
A suitable position must be found for the inverter while the PV-plant is designed. In
the following you will find a summary of the most important criteria.
Criteria for device mounting:
• Due to the high protection class (NEMA 4X) of the enclosure the installation is
possible indoors as well as outdoors.
• If possible, do not expose the inverter to rain despite NEMA 4X.
• Keep the DC-cabling from the solar panel to the inverter as short as possible.
• Avoid installation in the living area because a slight noise emission is possible.
• Avoid mounting on resonant parts (e. g. thin wooden panels, plaster panels,
etc.). The Sunny Boy tends to slightly vibrate when under load.
• Provide accessibility for installation and later service.
• Installation in eye-height allows to easily read the operating LEDs or the Sunny
Display.

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CAUTION: Please note the following points in any case:
• The mounting background must be firm.
• The ambient temperature must be between -13 °F and +140 °F.
• The National Electrical Code (NEC) requires that the inverter be
connected to a dedicated circuit and no other outlets or device may
be connected to this circuit. See NEC Section 690-64(b)(1). The
NEC also impose limitations on the size of the inverter and the man-
ner in with it is connected to the utility grid. See NEC Section 690-
64(b)(2).
• Do not expose the string inverter to direct sunlight (if necessary in-
stall a shading roof).
• A minimum distance of 8 inch (200 mm) must be clear above the in-
verter for ventilation, i. e. no cupboards, ceiling, etc.
• Free air circulation around the case must not be obstructed.
• If you are installing the Sunny Boy in a cabinet or closet etc., the ai
r
circulation must be sufficient for heat dissipation - provide external
ventilation.
• The heat sink can reach a temperature of more than 175 oF.
• Check existing electrical installations or plumbing prior to drilling
holes into the wall.
• Provide a correct position of the inverter - see below:
mount straight or tilted to the back never mount tilted to front
Fig. 2.1: How to mount the Sunny Boy

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The Sunny Boy inverter is mounted on the back side with the three metal straps.
Total height of the Sunny Boy: 295.50 mm
=
=
Total width of the Sunny Boy: 434.50 mm
+
++
Drilling Template for the Sunny Boy 2000, 2500, 3000
63,50 mm
position of the holes on the top
(for 6 mm screws)
bottom hole
(6 mm diam.)
distance between the holes on the top 217.50 mm
top
Please note:
mount the Sunny Boy
tilted to the back or
vertical!
Never mount the
Sunny Boy tilted
to the front!
vertical distance between the holes: 220.50 mm
Fig. 2.2: Picture of drilling template - original template in appendix

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Preparing the Mounting
The Sunny Boy is mounted on its back side with the 3 metal straps. For that 3 screws
and 3 according dowels (wall anchors) are necessary. The screws and dowels are
not included. We recommend 6 mm screws and 8 mm dowels.
NOTE: For outside mounting use stainless steel screws. Use a plastic
washer in order to avoid scratching the paint.
Fig. 2.3: Side view of the mounting to wall
Metal straps for mounting: The top straps take the load, the bottom is screwed
down in order to prevent the tilting off the wall.
Mounting to wall
• Mark the holes with the drilling template.
• Drill the holes (and put in the wall anchors), put in the screws of both top holes
and screw them in until ca. 4 mm are sticking out.
• Hang the inverter into the two top screws.
• Fasten the bottom screw. This will prevent lifting of the inverter case.
• Check the mounting of the inverter.

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2.3 Electric Connection
The electric connection of the Sunny Boy can be done once the device is correctly
mounted in its position.
Fig. 2.4: Simplified electrical wiring diagram of the PV-system
Fig. 2.5: Underside view of the Sunny Boy
DC- Connection
AC- Connection
GFDI-Fuse
Communication-
Connection

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WARNING: All electrical installations shall be done in accordance with all
local electrical codes and the National Electrical Code (NEC), ANSI/NFPA
70. Use no. 14 AWG, minimum 90 °C (194 °F), copper wire for all connec-
tions with the Sunny Boy. Voltage drop and other considerations may dic-
tate that larger wire sizes be used.
The AC-grid and the input from the DC disconnect enclosure are connected to the
inverter inside the case. Cables with wire sizes up to 10 AWG (5.26 mm2) are ac-
cepted by the AC- and DC-terminals on the printed circuit board.
WARNING: The connection of the Sunny Boy to the DC-voltage from the
PV string and the AC-voltage of the utility must be done in the order de-
scribed here. This ensures that the disconnecting of contacts as well as
hazardous voltages during the installation are avoided.
• Connect the Sunny Boy to the electricity grid
• Connect the PV strings to the DC disconnect enclosure
• Connect the DC disconnect enclosure to the Sunny Boy
• Connect the utility by switching all breakers ON
To disconnect the Sunny Boy from the system, first turn all breakers and switches
OFF. Then disconnect the various conductors in the reverse order listed above.

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2.3.1 Preparation of the electric connection
Remove all screws (1 - 4, size M5 (see Fig. 2.6)) and take off the lid. When removing
these screws, be sure to save the special lock washers and reinstall them to properly
ground the front panel.
Fig. 2.6:Front view of the Sunny Boy 2500U
You now have the opened Sunny Boy in front of you (see Fig. 2.7) and can see the
position of components and clamps relevant for you. You will find:
• The internal grid fuse
WARNING: A defective grid fuse has to be replaced only with same types
and rating of fuse in order for continued protection against risk of fire. The
type is Littelfuse 314015 15 AMP 250V AC.
• The control system board with the socket for the Piggy Back board for the
communication
• Terminal for the AC-connection
• Terminals for the DC-connection
1
2
3
4

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Fig. 2.7: Interior of the Sunny Boy 2500U
DC-Connection
Place for Piggy Back
Resistors
Grid Fuse
AC-Connection

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2.3.2 Connection to Electrical Utility Grid
The Sunny Boy must be connected to the grid with 3 cables
• with two phases (L1) and (L2) and one equipment-grounding conduc-
tor(Protective earth (PE)).
WARNING: Make sure the main 240 V breaker in the main utility breake
r
box is switched OFF before you connect the AC terminal block.
The grid impedance value at the connection point should be as low as possible to
avoid an increase of the AC-voltage to non-permissible values while the Sunny Boy
feeds to the grid. This also results in a higher system efficiency.
EXAMPLE: The impedance is the sum of the electricity grid impedance at
house distribution and all impedance values of cables and clamping
points.
NB: Impedance values are
• ca. 0.44 Ωfor a 70 feet (16.4 m) cable with a cross section of
AWG 14
• ca. 0.40 Ωfor a 100 feet (33 m) cable with a cross section of
AWG 12
• ca. 0.43 Ωfor a 175 feet (57 m) cable with a cross section of
AWG 10
The total impedance of the grid plus the interconnecting ac cables should be less
than 1.25 Ohm.

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Fig. 2.8: AC connection socket
• Connect the main 240 Volt AC-breaker box to the Sunny Boy by a 1/2“ conduit.
• Insert the conduit fitting in the very right opening of the Sunny Boy. Fasten the
fitting on the inside of the Sunny Boy with the nut.
• Pull the wires through the conduit into the interior of the Sunny Boy.
• Connect the wire L1 to the terminal labeled L in the Sunny Boy (see Fig. 2.8).
• Connect the wire L2 to the terminal labeled N in the Sunny Boy.
• Connect the equipment-grounding conductor to the terminal labeled PE in the
Sunny Boy.
• Torque wires with torque of 35 in-lb.
• Ensure all connections are correctly wired and properly torqued.
L1
L2
Ground
AC conduit and wiring

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Connection of the PV-panels to the DC disconnect enclosure
WARNING: Completely cover the surface of all PV-arrays with opaque (dark)
material before wiring them. PV-arrays produce electrical energy when ex-
posed to light and could create a hazardous condition.
Depending on the type of PV-module used it is possible to connect one single string
or several parallel strings. Therefore there are three connections for both the + and
the - pole. Within the device these connections are connected in parallel each.
WARNING: Before connecting the connectors of the PV-panel to the DC
disconnect enclosure check the correct polarity and admissible PV-panel
voltage between the + and the - cable connectors of the PV-panel.
The PV-panel open circuit voltage must be below or at most equal to
600 V DC (VPV ≤600 V DC) under all conditions. Please read chapter 7.1.1

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Connection of the Sunny Boy to the DC disconnect enclosure
• Install the DC conduit from the DC disconnect enclosure to the Sunny Boy.
• Insert the conduit fitting in the very left opening of the Sunny Boy. Fasten the
fitting on the inside of the Sunny Boy with the nut. Do the same at the DC dis-
connect enclosure .
• Ensure all circuit breakers in the DC disconnect enclosure are in the OFF-
position.
• Route the wires from the DC disconnect enclosure through the conduit and into
the Sunny Boy.
• Connect the positive (+) wire to the terminal block labeled with (+), see Fig. 2.9.
• Connect the negative(-) wire to the terminal block labeled with (-), see Fig. 2.9.
• Torque wires with torque of 35 in-lb .
• Ensure all connections are correctly wired and properly torqued.
Fig. 2.9: DC connection socket
DC- conduit and wiring
Positive plug Negative plug

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3 Commissioning
Safety Notice
NOTE: Make sure that nothing is on top of the heat sink of the Sunny Boy
when it is running.
WARNING: The heat sink can get very hot - i. e. over 175 °F (80 °C).
NOTE: Make sure that all fittings are sealed and all openings on the bottom
are closed with the seals.
• When putting the lid on make sure the seal in the inner side of the lid is
placed correctly. When screwing the inner screws make sure that the
thread in the Sunny Boy case is not damaged by tilted screws. Unde
r
certain conditions the enclosure type NEMA 4X cannot be guaranteed
any more. When mounting the Sunny Boy outside moisture can get into
the device and damage the electronics.
WARNING: Make sure that the lid is closed before applying power to
the Sunny Boy.
• Ensure that all ÁC and DC wiring is correct.