Studer Solsafe concept Application Note

Application Note 003

Anti-blackout system for grid connected solar installations (Solsafe concept)

General description

The Solsafe concept is a system which will automatically switch from a grid feeding inverter connected to the public grid to a backup grid powered by an invertercharger.

The installation of the Solsafe concept in a grid connected solar system enables to secure totally or partially the power supply in case of a power cut and allows the use of solar power when the grid is off.

Features & advantages

 Backup system for grid connected solar

installation.

 Grid feeding with solar inverter.

 Hassle free cabling, quick installation

and easy commissioning with the Solsafe S-Box.

Application Schematic

Minimal configuration

 Range of inverters

o Compact Series :

o All XPC serie o All C serie o All HPC serie

o Xtender Series :

o All XTH serie o All XTM serie

 Xtender

o Software vers. : 1.3.28 and higher

 RCC02 / 03 (Only for Xtender series)

o Software vers. : 1.3.32 and higher o RCC User level : Expert

AN003-V.3.0.6-10 | © STUDER INNOTEC SA

Figure 1, Solsafe concept with the Solsafe S-Box

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Detailed description

The Solsafe concept

The Solsafe concept is a backup system for grid connected solar installations.

This solution enables to secure totally or partially the power supply in case of a power cut, and to keep on using the solar energy being produced.

Note that all inverter-chargers of Studer Innotec are bi-directional. This allows integrating any of them into the Solsafe concept.

The Solsafe system can be fully wired by the

Application Note 003

installer. In that case, Studer is only supplying the inverter-charger (Xtender or Compact series) and the ARM-01 Module (for Compact series only).

The wiring schematics for the Solsafe system and Solsafe three phase system are at disposal in the appendices (available at the end of this document).

Solsafe S-Box

For the Solsafe system a cabling solution exists, the S-Box.

The S-Box offers :

 Hassle free cabling  Quick installation  Easy commissioning

Figure 3, Solsafe concept

Compared to other similar solutions, the Solsafe concept offers the following advantages :

 It allows a great flexibility by choosing

independently the grid-feeding power (matching the solar generator) and the stand-alone power (matching the peak consumption of the user).

 The grid-feeding inverter can be chosen with

high voltage input range (lowering wiring costs).

 The wiring can be optimized by placing the

grid-feeding inverter near the solar field

 It allows a possible upgrade of existing grid-

connected installations.

 The inverter-charger allows a fast charge

from the grid (important in case of frequent power cuts hindering a complete charge of the battery).

 The power available in case of islanding is

added (inverter-charger Pnom + grid-feeding instantaneous power).

 Its allows an upgrade of existing stand-alone

installations that are connected to the grid afterwards (adding value to the investment)

 It standardizes the amount of products to

maintain and makes the staff training easier (this concept can be implemented with all our combis, XTH, XTM, XPC, Compact and HPC).

 It allows to work with standard grid-feeding

inverters (SolarMax, Fronius, …).

The S-Box can be supplied in 4 versions :

 S-Box 25A for Compact Series (S-Box-25C)  S-Box 25A for Xtender Series (S-Box-25X)  S-Box 25A with ENS Module for Compact

Series (S-Box-25C-E)

 S-Box 25A with ENS Module for Xtender

Series (S-Box-25X-E)

Figure 2, S-Box

 It ensures that no grid-feeding from the

battery is possible.

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Solsafe concept situations

The Solsafe concept can be described by these four different situationsi

The grid is present

K1 / AUX1 is in “bypass



mode”.



K2 / AUX2 is switched on the grid (feeding grid).



The grid charges the batteries.

No grid and batteries fully charged

K1 / AUX1 is in “power cut



mode”: the backup inverter supplies the consumers from the batteries.



K2 / AUX2 is switched on the grid. Solar energy is not necessary as long as the battery is “full”.

Application Note 003

No grid and batteries partly charged

K1 / AUX1 is in “power cut



mode”: the consumers are supplied by the backup inverter (batteries) and / or solar energy.



K2 / AUX2 is switched on the backup grid. Solar energy is used for supplying the consumers and/or the batteries.(Bidirectional output of inverters)

No grid and batteries discharged

K1 / AUX1 is in “bypass



mode” and disconnects completely the consumers. It will switch back in “power cut mode” when the battery will recover a partial charged level.



K2 / AUX2 is switched on the backup grid. Solar energy is used for charging the battery.

i

K1, 2 are for Compact series and AUX1, 2 are for Xtender Series

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Application Note 003

Solsafe system behavior example

The graph below shows in detail the behavior of the Solsafe system in every possible case

Grid

Secured loads

Battery volt age

Secured loads power

Solar power

OK OK

K1/ AUX1

K2/ AUX2

K11

K14-K15

K12

K13

Gene ral d escriptions

Grid present and battery in floating phase. The solar production is sold to the grid.

No grid, no solar production (night time). Secured loads supplied by the inverter-charger.

No grid but solar production. Secured loads are supplied by the solar production and if necessary by the invert er-charger.

No grid but solar production. Secured loads are supplied by the solar production. The excess of the solar production is used to charge the battery.

No grid and battery voltage too low (battery fully discharged). Loads will stay disconnected until battery has recovered 25% capacity.

Grid present. The charge of the battery is done from the grid. The solar production is sold to the grid.

Relays descriptions

K1 / AUX 1 is always actuated until warning for LVD (low voltage disconnection), and actuated again when battery level is 50%.

K2 / AUX 2 is actuated when the unit is in inverter mode (no AC in) with a battery voltage which is less t han the absorption voltage and the temperature less than 65°C.

K14 is closed when the grid is present or when K11 is open.

K15 force K14 when the grid is present.

K12 and K13 are mechanically and electrically interlocked.

K11 and K14 are mechanically and electrically interlocked.

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Solsafe concept, installation design and commissioning

General information for Solsafe concept with Compact series

This particular application requires a Compact (XPC, C or HPC) driving the external auxiliary relay module ARM-01

The ARM-01 is a module consisting of 4 auxiliary relays to use only with the Compact series. The K1 and K2 relays have a dedicated function to the Solsafe application. The K3 relay is not used and the K4 relay is a replication of the auxiliary contact of the inverter-charger and can be programmed for particular applications

This module is already included in the S-Box (type S-Box-25C).

Using the S-Box (type S-Box-25C) will greatly

facilitate the wiring of Solsafe system.

General information for Solsafe concept with Xtender series

This particular application requires an Xtender (XTH or XTM) with auxiliary contact AUX1 and AUX2 specifically programmed to drive the contactor of the source switch-over.

inverter is not similar to the one of the grid)

Application Note 003

ii

. Thus, if the function “jumps impedance” is mandatory, it is required to add an external ENS module in the grid feeding path.

Studer Innotec recommends two ENS modules of the company UfE GmbH. The ENS 26 for single phase system and the ENS 31 for three phase system.

The module ENS 26 is already included in the

S-Box type S-Box-25C-E and S-Box-25X-E.

System dimensioning

Grid Inverter

The power of the grid inverter can be freely chosen but the maximum output power should not be higher than the inverter-charger nominal power.

Note that the wiring should be in accordance with the manufacturer’s and local’s prescriptions.

Battery

Battery should be sized according to the backup time requirement, but we recommend a minimum size of : C10 ≥ 5x P

Inverter-charger (Compact series or Xtender series)

pv/Ubatt

.

The specific programming is done by loading the preset Solsafe available in the libraries of predefined parameters (see the programming

guide on the next page for more information).

Using the S-Box (type S-Box-25X) will greatly

facilitate the wiring of Solsafe system.

General information for the Solsafe concept with Xtender three-phase system

This particular application requires 3 Xtender (XTH or XTM) with auxiliary contact AUX1 and AUX2 specifically programmed to drive the contactor of the source switch-over.

Note that Studer Innotec does not supply prewired S-Box for three-phase systems. But it is possible to order all the necessary equipment at Studer Innotec (List of equipment, preset Solsafe and information on the assembly are available in appendices).

ENS module

When using the Solsafe concept, the function “impedance jumps” (or ENS must be always turned off (impedance of

i

) on the grid inverter

The inverter-charger must be sized according to the maximum secured power.

For the Compact and Xtender series, the stand-by must be at 0 to work with the Solsafe system.

Notes

i

An ENS-Module is used to connect decentralized

electricity generators to the public electricity supply and in the event of faults in the mains supply, the ENSModule interrupts the feeding of electricity of the monitored phase into the mains to prevent an islanding effect. The following deviations are monitored :

 overvoltage and undervoltage  frequency deviation  impedance jumps

These instructions are directly extracted from Chapter

2.1 of Module ENS manual of the company UfE GmbH. More information available on www.ufegmbh.de

ii

Grid inverter manufacturer will give the procedure to

deactivate the function “impedance jumps”.

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RCC -02 / -03 programming guidei

Go to Expert level

User level {5012}

Your level is

i

The code is availabl e in the

user manual RCC -02 / -03

Load preset “Solsafe”

ii

Application Note 003

Press SET and search with :

Press SET and insert the code :

426468

Press SET :

EXPERT

Press SET and searc h with :

Save and restore

files {5013}

Press SET and search with :

Advanced backup

functions

{5069}

Press SET and search with :

Save and restore

Xtender files

{5050}

Press SET and search with :

Load Xtender

parameters preset

{5045}

Press SET and choose the preset '' Solsafe'' with and press SET to validate:

Wait until the pr eset

is installed

Notes

i

(Only for Solsafe concept with Xtender series and Solsafe concept with Xtender three phase system).

ii

Preset “Solsafe” description available in the appendices.

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Application Note 003

Notes

__________________________________________________________________________________

Worldwide sales and service

Switzerland

Studer Innotec SA Rue des Casernes 57 1950 SION / Switzerland Tel :027 205 60 80 / Fax : 027 205 60 88 Email: info@studer-innotec.com Web : http://www.studer-innotec.com

Limitation of responsibility

The use of STUDER INNOTEC SA devices is the responsibility of the customer in all cases. STUDER INNOTEC SA reserves the right to make any modification to the product without prior notification.

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Appendices

- Appendix 1, S-Box scheme (Power)

- Appendix 2, S-Box scheme (Control)

- Appendix 3, Scheme Compact series and S-Box-25C(-E)

- Appendix 4, Scheme Xtender series and S-Box-25X(-E)

- Appendix 5, Scheme Xtender three-phase system

Application Note 003

- Appendix 5.1, List of parts

- Appendix 5.2, Example of wiring

- Appendix 5.3, Description of the preset Solsafe

Appendices

g

)

p

Appendix 1, S-Box scheme (Power)

Application Note 003

Grid (Consumption counter)

Backup grid

Inverter-Charger output

Appendices – Page 1 / 9

Grid inverter output

Note : If the ENS-Mo dule is required,

laces the connections of X4

it re

Grid (Feedin counter

Appendix 2, S-Box scheme (Control)

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X8- X8-

X8-NO1 X8-NO2

Grid (Consumption counter)

Appendices – Page 2 / 9

Inverter-Charger output

Grid (Feeding counter)

Appendix 3, Scheme Compact series and S-Box-25C(-E)

Application Note 003

This drawing shows a working principle and should not be considered as a wiring proposal. The local regulation should be respected. In this scheme, the inverter-charger is a simple user of the grid and when the grid is present, the battery gets charged and maintenance comes from the grid.

TBD : To be defined for respect the local

regulation

Appendices – Page 3 / 9

Appendix 4, Scheme Xtender series and S-Box-25X(-E)

Application Note 003

This drawing shows a working principle and should not be considered as a wiring proposal. The local regulation should be respected. In this scheme, the inverter-charger is a simple user of the grid and when the grid is present, the battery gets charged and maintenance comes from the grid.

TBD : To be defined for respect the local

.

regulation

Appendices – Page 4 / 9

Appendix 5, Scheme Xtender three-phase system

Application Note 003

This drawing shows a working principle and should not be considered as a wiring proposal. The local regulation should be respected. In this scheme, the inverter-charger is a simple user of the grid and when the grid is present, the battery gets charged and maintenance comes from the grid.

TBD : To be defined for respect the local

regulation

Appendices – Page 5 / 9

r

Appendix 5.1, List of parts

The various components listed below are available in kit form at Studer Innotec.

Name of the kit Solsafe-Kit-Compact

Description

Single-phase Solsafe Kit with Compact series

Designation Studer reference Quantity

Single-phase breaker [25A] DISJ-MG-MONO-25A-C 2 Installation relay [16A] REL-INSTAL-16A 1 Contactor three-phase [Allen-Bradley 32A]

Mechanical lock block for contactor

Junction block [Woertz – 6mm2 – Grey] B-WOERTZ-6#-GRIS 9 Junction block [Woertz – 6mm2 – Blue] B-WOERTZ-6#-BLEU 5 Junction block [Woertz – 6mm2 – Yellow/Green]

Closure for junction block [Woertz]

Fuse block [Woertz – 4mm2 – Grey] B-WOERTZ-4#-FUSIBLE 3 Locking block [6/6 – Grey] B-BUTEE-PLASTIQUE 2

ARM-01 module (incl. cable of 5 meter) ARM-01 1

REL-CONTACTEUR-3L-32A-230V 4

REL-CONTACTEUR-BLOCVERROU

B-WOERTZ-6#-JAUNE-VERT 5

B-WOERTZ-PAROI-DEFERMETURE

2

Optional

ENS26 [UFEgmbh] ENS26 1 Fuse block [Woertz – 4mm2 – Grey] B-WOERTZ-4#-FUSIBLE 1

Name of the kit Solsafe-Kit-Xtende

Description

Single-phase Solsafe Kit with Xtender series

Designation Studer reference Quantity

Single-phase breaker [25A] DISJ-MG-MONO-25A-C 2 Installation relay [16A] REL-INSTAL-16A 1 Contactor three-phase [Allen-Bradley 32A]

Mechanical lock block

Junction block [Woertz – 6mm2 – Grey] B-WOERTZ-6#-GRIS 9 Junction block [Woertz – 6mm2 – Blue] B-WOERTZ-6#-BLEU 5 Junction block [Woertz – 6mm2 – Yellow/Green]

Closure for junction block [Woertz]

Fuse block [Woertz – 4mm2 – Grey] B-WOERTZ-4#-FUSIBLE 3 Locking block [6/6 – Grey] B-BUTEE-PLASTIQUE 2 SD card with Solsafe preset SD-CARD-SOLSAFE 1

REL-CONTACTEUR-3L-32A-230V 4

REL-CONTACTEUR-BLOCVERROU

B-WOERTZ-6#-JAUNE-VERT 5

B-WOERTZ-PAROI-DEFERMETURE

2

Optional

ENS26 [UFEgmbh] ENS26 1 Fuse block [Woertz – 4mm2 – Grey] B-WOERTZ-4#-FUSIBLE 1

Three-phase breaker [25A] DISJ-MG-TRI-25A-C 2 Installation relay [16A] REL-INSTAL-16A 1 Contactor three-phase [Allen-Bradley 32A]

Mechanical lock block

Junction block [Woertz – 6mm2 – Grey] B-WOERTZ-6#-GRIS 19 Junction block [Woertz – 6mm2 – Blue] B-WOERTZ-6#-BLEU 5 Junction block [Woertz – 6mm2 – Yellow/Green]

Closure for junction block [Woertz]

Fuse block [Woertz – 4mm2 – Grey] B-WOERTZ-4#-FUSIBLE 3 Locking block [6/6 – Grey] B-BUTEE-PLASTIQUE 2 SD card with Solsafe preset SD-CARD-SOLSAFE 1

ENS31 [UFEgmbh] ENS31 1 Fuse block [Woertz – 4mm2 – Grey] B-WOERTZ-4#-FUSIBLE 3

Application Note 003

Name of the kit Solsafe-Kit-Xtender_3ph

Description

Designation Studer reference Quantity

Three-phase Solsafe Kit with Xtender series

REL-CONTACTEUR-3L-32A-230V 4

REL-CONTACTEUR-BLOCVERROU

B-WOERTZ-6#-JAUNE-VERT 5

B-WOERTZ-PAROI-DEFERMETURE

2

Optional

Appendices – Page 6 / 9

Appendix 5.2, Example of wiring

Application Note 003

The box

The distances between the bars of support must be respected so all components of the system can fit in the box.

This system can be connected in any electrical box whose size permits it.

The wiring must be according to the local regulation

The bars of support are not provided by Rittal.

The assembling

At the top of the box are wired :

Relays K15, K14, K11, K12 and K13 and fuse holders F11 and

F12.

At the bottom of the box are wired :

Fuse holders F13, F14 and F15 and the terminals X1, X2, X3, X6,

X7 and X8

The cables must be wired as close as possible to relays and contacts to leave a place for the ENS 31

Appendices – Page 7 / 9

Finally, connect the ENS31 with particular attention to the order of phases

Note that the neutral must be connected to the ENS31 otherwise

Here are added onto the middle bar the ENS31 relay’s K10.1 and K10.2 and on the bottom bar the ENS31 fuse holder’s F16, F17 and F18.

the unit may be damaged. (All references for the ENS31 are in its

user manual.)

Application Note 003

It makes sense to put ENS31 before placing K10.1 and K10.2 to adjust the height of the central bar. Then, remove the ENS31 to

facilitate wiring K10.1 and K10.2 and remplace it.

Appendices – Page 8 / 9

Application Note 003

Appendix 5.3, Description of the preset “Solsafe” for Xtender series

If it is not possible to obtain the preset “Solsafe”, it is possible to set by yourself the RCC -02 / -03 using the parameter description below.Applicable from soft.

version 1.3.8 and higher | XTH/M 12 – 24 – 48 VDc

------------------------------------------------

Menu Combi Inverter-Charger Param 1438: Solsafe system presence | Yes

------------------------------------------------

Menu Inverter

Param 1187: Stand-by level | 0

------------------------------------------------

Auxiliary contact 1 {1201}

Load shedding when the battery is almost empty and load reconnected when battery back to 2,25V/cell. By default: load shedding means Aux. relay activated when battery ok.

Param 1202: Operating mode (AUX 1) | Value: reversed automatic

Param 1497: Combination of the events the auxiliary contact 1 |

Value: Any (Function OR)

------------------------------------------------

Menu 1245: Active in function of the battery voltage (AUX 1)

Param 1288: Use of dynamic compensation of battery level (AUX 1) |

Yes

Param 1246: Battery voltage 1 activate (AUX 1) | Yes

Param 1247: Battery voltage 1 (AUX 1) | 11.6 – 23.2 – 46.4 [VDc]

Param 1248: Delay 1 | 1min

Param 1249: Battery voltage 2 activate (AUX 1) | Yes

Param 1250: Battery voltage 2 (AUX 1) | 12 – 24 – 48 [VDc]

Param 1251: Delay 2 | 10min

Param 1252: Battery voltage 3 activate (AUX 1) | Yes

Param 1253: Battery voltage 3 (AUX 1) | 12.2 – 24.3 – 48.6 [VDc]

Param 1254: Delay 3 | 30min

Param 1255: Battery voltage level to deactivate (AUX 1) | 13.5 – 27V

– 54 [VDc]

Param 1256: Delay to deactivate (AUX 1) | 60min

Param 1516: Deactivate if battery in floating phase (AUX1) | No

Warning: None of the other parameters present in relay AUX1 menu should be changed!

Auxiliary contact 2 {1310}

Condition to have the grid inverter re-directed at the output of the Xtender. By default: disconnected

Param 1311: Operating mode (AUX 2) | Value: automatic

Param 1498: Combination of the events the auxiliary contact 2 |

Value: All (Function AND)

------------------------------------------------

Menu 1456: Contact active on event, only theses parameters:

Param 1340: Inverter active | Yes

Param 1519: Xtender ON (AUX 2) | Yes

Param 1521: No over-temperature, no overload, no transformer over

temperature | Yes

Param 1333: Xtender OFF (AUX 2) | No

Param 1334: Battery undervoltage (AUX 2) | No

Param 1335: Battery overvoltage (AUX 2) | No

Param 1336: Inverter or Smart-Boost overload (AUX 2) | No

Param 1337: Overtemperature (AUX 2) | No

------------------------------------------------

Menu 1353: Active in function of the of battery voltage (AUX 2)

Param 1354: Use of dynamic compensation of battery level (AUX 2) |

Yes

Param 1355: Battery voltage 1 activate (AUX 2) | Yes

Param 1356: Battery voltage 1 (AUX 2) | 13 – 26V – 52 [VDc]

Param 1357: Delay 1 | 5min

Param 1364: Battery voltage level to deactivate (AUX 2) | 14 – 28V –

56 [VDc]

Param 1365: Delay to deactivate (AUX 2) | 0min

Warning: None of the other parameters present in relay AUX2 menu should be changed!

Appendices – Page 9 / 9

Studer Solsafe concept Application Note

Specifications and Main Features

Frequently Asked Questions

User Manual