Surge protection for your photovoltaic systems

RESIDENTIAL HOMES
COMMERCIAL AND INDUSTRIAL BUILDINGS
GROUND-MOUNTED PV SYSTEMS
STATE OF THE ART
PRODUCT SELECTION
DOWNLOADS

SELECTION AND PLACEMENT OF SPDs

Selection and placement of SPDs in a PV system in accordance with IEC 61643-32

RESIDENTIAL HOMES

Installation locations for surge protection in PV systems for detached houses

Comprehensive protection for all areas

In practice, a distinction is made between buildings with and without external lightning protection. If external lightning protection is not required for a building, it can be assumed that there is no increased risk of a direct lightning strike. Surge protection on the DC side of the photovoltaic system therefore only needs to be installed to protect against indirectly coupled surges. In this case, a Type 2 SPD (DS50VGPVS) must be installed on both the PV generator and the inverter. If the cable lengths between the generator and the inverter are negligible (<10 m), one of the two surge protection devices can be omitted. The string cables of the generator wiring may form a large inductive loop during inductively coupled overvoltage events, such as nearby lightning strikes within a radius of approximately 2 km. To achieve a higher level of safety beyond the standard requirements, CITEL recommends using a Type 1+2 combined SPD (DS50VGPVS/12KT1) even in buildings without external lightning protection. On the AC side, Type 1+2+3 combined SPD (ZPAC or DAC1-13VGS) in the meter cabinet provide optimal protection. This protects both the AC input of the inverter and the building’s electrical installation. For homes with external lightning protection—which is generally not required—more extensive regulations apply; we would be happy to provide you with detailed information on these upon request.

Installation location	Product Name	Description	Product image
Main Distribution Board	ZPAC1-13VG-PRO-SU	Type 1+2+3 Combined SPD with VG Technology for 40 mm busbar, 10-year warranty, surge current rating per pole: Iimp = 8 kA (10/350 μs), free of operating and leakage currents, complies with standards IEC 61643-11 and EN 61643-11, VDE-AR-N 4100 compliant, integrated fuse, dual voltage taps for RFZ and APZ, potential-free remote signaling contact
Main Distribution Board	DAC1-13VGS-31-275	Type 1+2+3 Combined SPD with VG Technology for DIN rail mounting, 10-year warranty, surge current per pole: Iimp = 12.5 kA (10/350 μs), free of operating and leakage currents, complies with standards IEC 61643-11 and EN 61643-11, VDE-AR-N 4100 compliant
At the building entrance / In front of the inverter	CiPlug1-DP6VG-1-XS	PV junction box for 1 MPP tracker / 1 string, Type 1+2+3 integrated surge protection (DPVN1-6CVG-21Y-1200), IP65 rating, connection via MC4 connectors
Multimedia section	DLA-12D3	Surge protection D1, C2 for measurement and control, telecommunications, and data technology applications; protected shield connection; operating current up to 300 mA; grounding via DIN rail or elevator terminal or spring-loaded terminal; Only 13 mm wide, pluggable protection module, complies with standards IEC 61643-21 and VDE 0845-3-1

Back to the top of the page

Commerce and Industry

Installation locations for surge protection on rooftop PV systems

Comprehensive Protection Concept

Since commercial and industrial buildings typically house high-value assets, and public institutions contain sensitive information and data, comprehensive protection is particularly important in these settings. A Type 1+2+3 combined SPD, such as the DACN1-25CVGS or the DAC1-13VGS, guarantees the best possible protection on the AC side through a low protection level < 1500 V, combined with a total lightning current withstand capacity of 100 kA (25 kA per pole).

Installation location	Product Name	Description	Product image
Main Distribution Board	DACN1-25CVGS-31-275	Combined SPD, Type 1+2+3, based on a gas-filled spark gap, 10-year warranty, breaking capacity per pole: In = 25 kA (8/20 μs); Iimp = 25 kA (10/350 μs), Safe disconnecting device, Remote signaling as standard, Optimized for TOV, Complies with standards IEC 61643-11 and EN 61643-11
Main distribution board or sub-distribution board	DAC1-13VGS-31-275	Type 1+2+3 Combined SPD with VG Technology for DIN rail mounting, 10-year warranty, surge current per pole: Iimp = 12.5 kA (10/350 μs), free of operating and leakage currents, complies with standards IEC 61643-11 and EN 61643-11, VDE-AR-N 4100 compliant
Sub-distribution board	DAC50VGS-31-275	Combined SPD Type 2+3, 4-pole (TT system, 3+1), 4 HP, Un: 230/400 V, Uc: 275 VAC, In: 20 kA, Imax: 50 kA per pole, with remote signaling, plug-in protection modules VG-Technology, 10-year warranty
At the building entrance / In front of the inverter	GAK4.K2x10.K1x10.DP6VG-1-XS	PV junction box for 4 MPP trackers / 2 strings, with integrated surge protection (Type 1+2+3 - 4x DPVN1-6CVG-21Y-1200), IP65 rating, connection via spring-loaded terminals
Multimedia section	DLA-12D3	Surge protection D1, C2 for measurement and control, telecommunications, and data technology applications; protected shield connection; operating current up to 300 mA; grounding via DIN rail or elevator terminal or spring-loaded terminal; Only 13 mm wide, pluggable protection module, complies with standards IEC 61643-21 and VDE 0845-3-1

Back to the top of the page

Ground-mounted solar power plants

Installation locations for surge protection in ground-mounted PV systems

Effective protection

Today, solar power plants are equipped with an ever-increasing array of technology. In addition to monitoring systems designed purely for performance monitoring, this includes, above all, an increasing number of sensors for recording and analyzing environmental conditions such as ambient temperature, module temperature, irradiance, and wind speed. The currents of the individual strings are also frequently measured with precision. In addition, tracking systems are sometimes used to automatically align the modules with the sun’s position. Protecting all these systems is particularly important here. Therefore, these data and control lines should be consistently included when developing the protection concept. Ground-mounted systems have a larger spatial footprint and are therefore at greater risk of lightning strikes during thunderstorms than compact rooftop systems. EN 61643-32 addresses this by mandating the use of Type 1 surge arresters on the DC side of ground-mounted systems.

Installation location	Product Name	Description	Product image
Main Distribution Board	DACN1-25CVGS-31-275	Combined SPD, Type 1+2+3, based on a gas-filled spark gap, 10-year warranty, breaking capacity per pole: In = 25 kA (8/20 μs); Iimp = 25 kA (10/350 μs), Safe disconnecting device, Remote signaling as standard, Optimized for TOV, Complies with standards IEC 61643-11 and EN 61643-11
Main distribution board or sub-distribution board	DAC1-13VGS-31-275	Type 1+2+3 Combined SPD with VG Technology for DIN rail mounting, 10-year warranty, surge current per pole: Iimp = 12.5 kA (10/350 μs), free of operating and leakage currents, complies with standards IEC 61643-11 and EN 61643-11, VDE-AR-N 4100 compliant
At the building entrance / In front of the inverter	GAK12.K2x10.K1x10.DP6VG-1-XS	PV junction box for 12 MPP trackers / 2 strings, with integrated surge protection - DPVN1-6CVG-21Y-1200 (combined SPD Type 1+2+3), IP65 protection rating, connection via spring-loaded terminals (6–10 mm²), screw connections permanently installed
Multimedia section	DLA-12D3	Surge protection D1, C2 for measurement and control, telecommunications, and data technology applications; protected shield connection; operating current up to 300 mA; grounding via DIN rail or elevator terminal or spring-loaded terminal; Only 13 mm wide, pluggable protection module, complies with standards IEC 61643-21 and VDE 0845-3-1

Back to the top of the page

Conclusion: DC side:

If a DC Type 1 SPD is required, an Iimp of 12.5 kA/pole (10/350) is sufficient for nearly all systems, regardless of the specific standards. The DS60VG series thus offers users a standards-compliant product that requires no complicated calculations during planning and can be used in nearly any system. If a detailed calculation or the application of Supplement 5 yields lower values, the DS50VGPVS-12KT1 series is available as a Type 1+2 SPDs with an Iimp of 6.25 kA/pole (10/350) as a cost- and space-optimized variant. The DS50VGPVS-G/51 series is used here as a DC Type 2 SPD.

Conclusion: AC side:

On the AC side, the DS250VG series (Type 1+2+3) with 25 kA per pole is available for the highest loads, while the DAC1-13VG or ZPAC series (Type 1+2+3) with 12.5 kA per pole is suitable for average loads. The DAC50VG series SPDs (Type 2+3) round out the AC side.

Zurück zum Anfang der Seite

STATE OF THE ART

Normative requirements

In addition to Supplement 5 of the lightning protection standard VDE 0185-305-3 (EN 62305-3) and the specifications of the Association of Property Insurers (Verband der Sachversicherer e.V.) in VdS Information Sheet 2010, the user had only the preliminary standard VDE V 0675-39-12 (CLC/TS 50539-12) at their disposal. Since September 2017, the new application standard IEC 61643-32 ED1 has been published at the international level, and its national implementation is reflected in the draft VDE 0675-6-32. The new DIN VDE 0100-712 now also includes additional requirements for protecting systems against overvoltages.

The new IEC 61643-32 is essentially based on the well-known VDE V 0675-39-12.

Both standards address the selection and application principles of surge protection devices for use in photovoltaic installations. They also provide guidelines for the selection and installation of surge protection devices on the DC and AC sides.

The exact wording of IEC 61643-32 is as follows:

“The installation of SPDs on the DC and AC sides of a PV system is mandatory, unless otherwise specified in a risk analysis ...”

The new IEC 61643-32 also requires the use of SPDs for data and communication lines (“If SPDs are installed to protect the PV system, it is necessary to also protect all telecommunications and signal circuits that are part of the PV system ...”).

The requirement to protect photovoltaic systems against power surges is also stipulated in the new DIN VDE 0100-712 standard.

This first refers to Supplement 5 of the lightning protection standard VDE 0185-305-3 (EN 62305-3):

“The selection and installation of surge protective devices (SPDs) in PV systems must be carried out in accordance with DIN EN 62305-3 Supplement 5 (VDE 0185-305-3 Supplement 5).”

This Supplement 5, in turn, contains the following requirement:

“The necessity of surge protection measures on the AC side of the PV power supply system is determined in accordance with DIN VDE 0100-443.”

As is well known, this standard mandates the use of SPDs in every installation. Furthermore, DIN VDE 0100-712 states:

“If protection against transient overvoltages is required by DIN VDE 0100-443, Section 443, such protection must also be applied on the DC side of the PV system.”

Minimum requirements according to DIN VDE 0100-712, Annex C

Situation	Main Distribution Board	Inverter		Solar panel array
Situation	Main Distribution Board	AC side	DC side	Solar panel array
Buildings without external lightning protection	SPD Type 2	SPD Type 2	SPD Type 2	SPD Type 2
Buildings with external lightning protection, Separation distance maintained	SPD Type 1	SPD Type 2	SPD Type 2	SPD Type 2
Buildings with external lightning protection, Separation distance not maintained	SPD Type 1	SPD Type 1	SPD Type 1	SPD Type 1

Weitere Normative Mindestanforderungen

Querschnitte:

Nicht blitzstrombehaftete Potenzialausgleichsleiter: Mindestens 6 mm² Kupfer oder gleichwertig.
Blitzstrombehaftete Potenzialausgleichsleiter: Mindestens 16 mm² Kupfer oder gleichwertig.

Auswahl von Uc und Up:

Uc > 1,2*Uocstc
Up < (5*Uocstc)x0,8 oder Up < Uwx0,8 (Uw: Spannungsfestigkeit der Betriebsmittel)

Ableitwerte nach:

A) DIN VDE 0100-712 und IEC 61643-32

Typ 1 Ableiter: min. Iimp: 12,5 kA/Pol (10/350)

Abweichende Iimp für Typ 1 Ableiter können sich je nach Risiko

für DC- Ableiter gemäß IEC 61643-32 Anhang A,
für AC-Ableiter gemäß Blitzschutzklasse und Blitzstromaufteilung nach EN 61643-12 ergeben

Typ 2 Ableiter (AC und DC): min. 5 kA/Pol (8/20)

B) VDE 0185-305-3 Beiblatt 5:2014:

Typ 1 Ableiter:

für DC-Ableiter nach Absatz 5.3.2, Tabelle 2 und 3:

2,5 kA/Pol (10/350) bis 25 kA/Pol (10/350) je nach Erdungskonzept, Anlagenaufbau bzw. Anlagentyp und Ableitertechnologie
für AC-Ableiter in der Nähe vom:

Wechselrichter: mind. 12,5 kA/Pol (10/350).

Einspeisepunkt bzw. Blitzschutzzonenübergang gemäß Blitzschutzklasse und Blitzstromaufteilung nach EN 61643-12 ggf. Werte bis 25 kA/Pol (10/350).

Typ 2 Ableiter (AC und DC): min. 5 kA/Pol (8/20)