Lightning and surge protection

for rooftop photovoltaic systems

White Paper

Contents
Cable routing and earthing
of PV systems
Separation distance s as per
IEC 62305-3 (EN 62305-3)
Core shadows on solar cells
Special surge protective devices
for the d.c. side of PV systems
Type 1 and 2 d.c. arrester
for use in PV systems
Selection of SPDs according to
the voltage protection level Up
Building with and without exter-
nal lightning protection system
HVI Conductors
Module inverters

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 Lightning and surge protection
for rooftop photovoltaic systems
White Paper

At present, about one million PV systems are installed in sult which is understood by all parties involved. The software
Germany. Based on the fact that self-generated electricity compares the risk with the technical expenditure and provides
is generally cheaper and provides a high degree of electri- economically optimised protection measures.
cal independence from the grid, PV systems will become an Section 4.5 (Risk Management) of Supplement 5 of the
integral part of electrical installations in the future. How- German DIN EN 62305-3 standard describes that a light-
ever, these systems are exposed to all weather conditions ning protection system designed for class of LPS III (LPL III)
and must withstand them over decades. meets the usual requirements for PV systems. In addi-
The cables of PV systems frequently enter the building and tion, adequate lightning protection measures are listed
extend over long distances until they reach the grid connec- in the German VdS 2010 guideline (Risk-oriented light-
tion point. ning and surge protection) published by the German In-
Lightning discharges cause field-based and conducted surance Association. This guideline also requires that
electrical interference. This effect increases in relation with LPL III and thus a lightning protection system accord-
increasing cable lengths or conductor loops. Surges do not ing to class of LPS III be installed for rooftop PV systems
only damage the PV modules, inverters and their monitor- (> 10 kWp) and that surge protection measures be taken.
ing electronics, but also devices in the building installation. As a general rule, rooftop photovoltaic systems
More importantly, production facilities of industrial build- must not interfere with the existing lightning pro-
ings may also easily be damaged and production may come tection measures.
to a halt.
If surges are injected into systems that are far from the pow- Necessity of surge protection for PV systems
er grid, which are also referred to as stand-alone PV systems, In case of a lightning discharge, surges are induced on elec-
the operation of equipment powered by solar electricity (e.g. trical conductors. Surge protective devices (SPDs) which
medical equipment, water supply) may be disrupted. must be installed upstream of the devices to be protected
on the a.c., d.c. and data side have proven very effective in
Necessity of a rooftop lightning protection system protecting electrical systems from these destructive voltage
The energy released by a lightning discharge is one of the peaks. Section 9.1 of the CENELEC CLC/TS 50539-12 stand-
most frequent causes of fire. Therefore, personal and fire ard (Selection and application principles SPDs connected
protection is of paramount importance in case of a direct to photovoltaic installations) calls for the installation of
lightning strike to the building. surge protective devices unless a risk analysis demonstrates
At the design stage of a PV system, it is evident whether a that SPDs are not required. According to the IEC60364-4-44
lightning protection system is installed on a building. Some (HD 60364-4-44) standard, surge protective devices must
countries building regulations require that public build- also be installed for buildings without external lightning
ings (e.g. places of public assembly, schools and hospitals) protection system such as commercial and industrial build-
be equipped with a lightning protection system. In case of ings, e.g. agricultural facilities. Supplement 5 of the German
industrial or private buildings it depends on their location, DIN EN 62305-3 standard provides a detailed description of
type of construction and utilisation whether a lightning the types of SPDs and their place of installation.
protection system must be installed. To this end, it must be
determined whether lightning strikes are to be expected or Cable routing of PV systems
could have severe consequences. Structures in need of pro- Cables must be routed in such a way that large conductor
tection must be provided with permanently effective light- loops are avoided. This must be observed when combining
ning protection systems. the d.c. circuits to form a string and when interconnecting
According to the state of scientific and technical knowledge, several strings. Moreover, data or sensor lines must not be
the installation of PV modules does not increase the risk of a routed over several strings and form large conductor loops
lightning strike. Therefore, the request for lightning protection with the string lines. This must also be observed when con-
measures cannot be derived directly from the mere existence necting the inverter to the grid connection. For this reason,
of a PV system. However, substantial lightning interference the power (d.c. and a.c.) and data lines (e.g. radiation sensor,
may be injected into the building through these systems. yield monitoring) must be routed together with the equipo-
Therefore, it is necessary to determine the risk resulting from tential bonding conductors along their entire route.
a lightning strike as per IEC 62305-2 (EN 62305-2) and to take
the results from this risk analysis into account when installing Earthing of PV systems
the PV system. For this purpose, DEHN offers the DEHNsupport PV modules are typically fixed on metal mounting systems.
Toolbox software which allows to determine the risk. A risk The live PV components on the d.c. side feature double or
analysis performed by means of this software provides a re- reinforced insulation (comparable to the previous protective

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Lightning and surge protection
for rooftop photovoltaic systems
White Paper

insulation) as required in the IEC 60364-4-41 standard. The

metal substructure combination of numerous technologies on the module and
inverter side (e.g. with or without galvanic isolation) results
equipotential in different earthing requirements. Moreover, the insulation
bonding at least monitoring system integrated in the inverters is only perma-
6 mm2 Cu nently effective if the mounting system is connected to earth.
Information on the practical implementation is provided in
external lightning Supplement 5 of the German DIN EN 62305-3 standard. The
protection system;
metal substructure is functionally earthed if the PV system is
separation distance
s is maintained
located in the protected volume of the air-termination sys-
tems and the separation distance is maintained. Section 7
of Supplement 5 requires copper conductors with a cross-
Figure 1 Functional earthing of the mounting systems if no external
section of at least 6 mm2 or equivalent for functional earthing
lightning protection system is installed or the separation (Figure 1). The mounting rails also have to be permanently
distance is maintained (DIN EN 62305-3, Supplement 5) interconnected by means of conductors of this cross-section.
If the mounting system is directly connected to the external
lightning protection system due to the fact that the separa-
tion distance s cannot be maintained, these conductors be-
metal come part of the lightning equipotential bonding system.
substructure Consequently, these elements must be capable of carrying
lightning currents. The minimum requirement for a lightning
equipotential protection system designed for class of LPS III is a copper
bonding at least conductor with a cross-section of 16 mm2 or equivalent.
16 mm2 Cu
Also in this case, the mounting rails must be permanently
external lightning interconnected by means of conductors of this cross-section
protection system; (Figure 2). The functional earthing/lightning equipotential
separation distance bonding conductor should be routed in parallel and as close
s is not maintained as possible to the d.c. and a.c. cables/lines.
lightning current
carrying connection UNI earthing clamps (Figure 3) can be fixed on all common
mounting systems. They connect, for example, copper con-
Figure 2 Lightning equipotential bonding for the mounting systems ductors with a cross-section of 6 or 16 mm2 and bare round
if the separation distance is not maintained wires with a diameter from 8 to 10 mm to the mounting
system in such a way that they can carry lightning currents.
The integrated stainless steel (V4A) contact plate ensures
corrosion protection for the aluminium mounting systems.

Separation distance s as per IEC 62305-3 (EN 62305-3)

A certain separation distance s must be maintained between
a lightning protection system and a PV system. It defines
the distance required to avoid uncontrolled flashover to ad-
jacent metal parts resulting from a lightning strike to the
external lightning protection system. In the worst case, such
an uncontrolled flashover can set a building on fire. In this
case, damage to the PV system becomes irrelevant. Details
on the calculation of the separation distance s can be found
in chapter 5.6 and can be easily and quickly calculated by
means of the DEHN Distance Tool software (chapter 3.3.2).

Core shadows on solar cells

Figure 3 UNI earthing clamp: A stainless steel intermediate element The distance between the solar generator and the external
prevents contact corrosion, thus establishing reliable long- lightning protection system is absolutely essential to prevent
term connections between different conductor materials excessive shading. Diffuse shadows cast by, for example

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 Lightning and surge protection
for rooftop photovoltaic systems
White Paper

overhead lines, do not significantly affect the PV system and

the yield. However, in case of core shadows, a dark clearly
outlined shadow is cast on the surface behind an object, distance l
in m
changing the current flowing through the PV modules. For air-ter-
this reason, solar cells and the associated bypass diodes must mination
rod in mm
not be influenced by core shadows. This can be achieved by
maintaining a sufficient distance. For example, if an air-ter-
core shadow
mination rod with a diameter of 10 mm shades a module,
the core shadow is steadily reduced as the distance from the
module increases. After 1.08 m only a diffuse shadow is cast
on the module (Figure 4). Annex A of Supplement 5 of the
German DIN EN 62305-3 standard provides more detailed air-termination rod x factor = distance l
information on the calculation of core shadows. 10 mm 108 1.08 m
16 mm 108 1.76 m
Special surge protective devices for the d.c. side of
photovoltaic systems Figure 4 Distance between the module and the air-termination rod
required to prevent core shadows
The U/I characteristics of photovoltaic current sources are
very different from that of conventional d.c. sources: They
have a non-linear characteristic (Figure 5) and cause long-
term persistence of ignited arcs. This unique nature of PV U [V]
current sources does not only require larger PV switches and
PV fuses, but also a disconnector for the surge protective PV generator
UOC UOC
device which is adapted to this unique nature and capable
of coping with PV currents. Supplement 5 of the German
DIN EN 62305-3 standard (subsection 5.6.1, Table 1) de-
ULB = f (i)
scribes the selection of adequate SPDs.
To facilitate the selection of type 1 SPDs, Tables 1 and 2 operating
conventional point
shown the required lightning impulse current carrying ca-
d.c. source
pability Iimp depending on the class of LPS, number of down
conductors of the external lightning protection systems as
ISC I [A]
well as the SPD type (voltage-limiting varistor-based ar-
rester or voltage-switching spark-gap-based arrester).
Figure 5 Source characteristic of a conventional d.c. source versus
SPDs which comply with the applicable EN 50539-11 the source characteristic of a PV generator. When switching
standard must be used. Subsection 9.2.2.7 of CENELEC PV sources, the source characteristic of the PV generator
CLC/TS 50539-12 also refers to this standard. crosses the arc voltage range

Number of down conductors of the external lightning protection system

<4 4
Class of LPS and
max. lightning current Values for the voltage-limiting type 1 SPDs or type 1 combined SPDs (series connection)
(10/350 s) based on a selection of I8/20 (8/20 s) and I10/350 (10/350 s)
ISPD1 = ISPD2 ISPD3 = ISPD1 + ISPD2 = Itotal ISPD1 = ISPD2 ISPD3 = ISPD1 + ISPD2 = Itotal
I8/20/I10/350 I8/20/I10/350 I8/20/I10/350 I8/20/I10/350
I or unknown 200 kA 17/10 34/20 10/5 20/10
II 150 kA 12.5/7.5 25/15 7.5/3.75 15/7.5
III and IV 100 kA 8.5/5 17/10 5/2.5 10/5
Table 1 Selection of the minimum discharge capacity of voltage-limiting type 1 SPDs (varistors) or type 1 combined SPDs (series
connection of varistors and spark gaps); according to CENELEC CLC/TS 50539-12 (Table A.1)

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Lightning and surge protection
for rooftop photovoltaic systems
White Paper

Number of down conductors of the external lightning protection system

Class of LPS and <4 4
max. lightning current Values for the voltage-switching type 1 SPDs or type 1 combined SPDs (parallel connection)
(10/350 s)
ISPD1 = ISPD2 ISPD3 = ISPD1 + ISPD2 = Itotal ISPD1 = ISPD2 ISPD3 = ISPD1 + ISPD2 = Itotal
Iimp Iimp Iimp Iimp
I or unknown 200 kA 25 50 12.5 25
II 150 kA 18.5 37.5 9 18
III and IV 100 kA 12.5 25 6.25 12.5
Table 2 Selection of the minimum discharge capacity of voltage-switching type 1 SPDs (spark gaps) or type 1 combined SPDs
(parallel connection of varistors and spark gaps); according to CENELEC CLC/TS 50539-12 (Table A.2)

Original 1. Activation 2. Arc 3. Electrical

state of the extinction isolation
disconnector

SCI SCI SCI SCI

Figure 7 Switching phases of the three-step d.c. switching device

integrated in DEHNguard M YPV SCI (FM)

Figure 6 DEHNcombo YPV SCI type 1 combined arrester for protect-

ing photovoltaic systems from surges and partial lightning
currents

Type 1 d.c. arrester for use in PV systems:

Multipole type 1 + type 2 combined d.c. arrester,
DEHNcombo YPV SCI (FM)
With their integrated SCI technology, DEHNcombo YPV SCI
(FM) combined arresters (Figure 6) fulfil the above men-
tioned requirements. In addition to the proven fault-resistant
Y circuit, DEHNcombo YPV SCI (FM) features a three-step d.c.
switching device (SCI technology). This d.c. switching device
consists of a combined disconnection and short-circuiting de-
vice with Thermo Dynamic Control and a fuse in the bypass Figure 8 DEHNlimit PV 1000 V2 spark-gap-based type 1 combined
path. This circuit (Figure 7) safely disconnects the arrester arrester
from the generator voltage in case of an overload and reli-
ably extinguishes d.c. arcs. Thus, DEHNcombo YPV SCI (FM)
allows to protect PV generators up to 1000 A without addi- is available for voltages UCPV of 600 V, 1000 V and 1500 V
tional backup fuse. This arrester combines a lightning current and has a width of only 4 modules. Therefore, DEHNcombo
arrester and a surge arrester in a single device, thus ensuring YPV SCI (FM) is the ideal type 1 combined arrester for use in
efficient protection of terminal equipment. With its discharge photovoltaic power supply systems.
capacity Itotal of 12.5 kA (10/350 s), it can be flexibly used Voltage-switching spark-gap-based type 1 SPDs, for exam-
for the highest classes of LPS. DEHNcombo YPV SCI (FM) ple DEHNlimit PV 1000 V2 (Figure 8), are another powerful

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 Lightning and surge protection
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SCI SCI

Figure 9 Modular DEHNguard M YPV SCI (FM) type 2 surge

arrester with fault-resistant Y circuit and three-step d.c.
switching device

Figure 11 DEHNguard type 2 SPD integrated in the inverter for the

a.c. and d.c. side

The numerous technologies combined in these arresters pre-

vent damage to the surge protective device due to insula-
tion faults in the PV circuit, the risk of fire of an overloaded
arrester and puts the arrester in a safe electrical state with-
out disrupting the operation of the PV system. Thanks to
the protective circuit, the voltage-limiting characteristic of
varistors can be fully used even in the d.c. circuits of PV
systems. In addition, the permanently active surge protec-
Figure 10 Ready-to-install type 2 DEHNcube YPV SCI 1000 1M surge
tive device minimises numerous small voltage peaks. Thus,
arrester the SCI technology increases the service life of the entire
d.c.-side PV system.

technology that allows to discharge partial lightning cur- Selection of SPDs according to the voltage
rents in case of d.c. PV systems. Thanks to its spark gap tech- protection level Up
nology and a d.c. extinction circuit which allow to efficiently The operating voltage on the d.c. side of PV systems dif-
protect downstream electronic systems, this arrester series fers from system to system. At present, values up to 1500 V
has an extremely high lightning current discharge capacity d.c. are possible. Consequently, the dielectric strength of ter-
Itotal of 50 kA (10/350 s) which is unique on the market. minal equipment also differs. To ensure that the PV system is
reliably protected, the voltage protection level Up of the SPD
Type 2 d.c. arrester for use in PV systems: DEHNguard must be lower than the dielectric strength of the PV system
M YPV SCI (FM) and DEHNcube YPV SCI ... it is supposed to protect. The CENELEC CLC/TS 50539-12
Reliable operation of SPDs in d.c. PV circuits is also indis- standard requires that Up is at least 20% lower than the
pensable when using type 2 surge protective devices. To this dielectric strength of the PV system. Type 1 or type 2 SPDs
end, the DEHNguard M YPV SCI (FM) and DEHNcube YPV must be energy-coordinated with the input of terminal
SCI... surge arresters also feature a fault-resistant Y protec- equipment. If SPDs are already integrated in terminal equip-
tive circuit and the SCI technology (Figure 9 and 10) and ment, coordination between the type 2 SPD and the input
are also connected to PV generators up to 1000 A without circuit of terminal equipment is ensured by the manufac-
additional backup fuse. turer (Figure 11).

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Lightning and surge protection
for rooftop photovoltaic systems
White Paper

GJB 6 mm2 Cu
PC
=
~

DNO Distribution network operator

M M GJB Generator junction box
DNO M Meter
SEB MEB Main earthing busbar
MEB SEB Service entrance box

No. in Fig. SPD *FM = Floating remote signalling contact Part No.
d.c. input of the inverter
Per MPPT DEHNguard DG M YPV SCI 1000 FM* 952 515
For 1 MPPT DEHNcube DCU YPV SCI 1000 1M 900 910
For 2 MPPTs DEHNcube DCU YPV SCI 1000 2M 900 920
a.c. output of the inverter
TN-S system DEHNguard DG M TNS 275 FM* 952 405
Low-voltage input
TN-C system DEHNguard DG M TNC CI 275 FM* 952 309
TN-S system DEHNguard DG M TNS CI 275 FM* 952 406
TT system DEHNguard DG M TT CI 275 FM* 952 327
Data interface
Two pairs, even with different operating BLITZDUCTOR BXTU ML4 BD 0-180 920 349
voltages up to 180 V + BXT BAS base part + 920 300
Functional earthing
Functional equipotential bonding UNI earthing clamp 540 250
Figure 12 Building without external LPS situation A (Supplement 5 of the DIN EN 62305-3 standard)

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 Lightning and surge protection
for rooftop photovoltaic systems
White Paper

separation
distance kept

GJB 6 mm2 Cu
PC
=
~

M M DNO Distribution network operator

GJB Generator junction box
DNO M Meter
SEB MEB Main earthing busbar
MEB s Separation distance
SEB Service entrance box

No. in Fig. SPD *FM = Floating remote signalling contact Part No.
d.c. input of the inverter
Per MPPT DEHNguard DG M YPV SCI 1000 FM* 952 515
For 1 MPPT DEHNcube DCU YPV SCI 1000 1M 900 910
For 2 MPPTs DEHNcube DCU YPV SCI 1000 2M 900 920
a.c. output of the inverter
TN-S system DEHNguard DG M TNS 275 FM* 952 405
Low-voltage input
TN-C system DEHNventil DV M TNC 255 FM* 951 305
TN-S system DEHNventil DV M TNS 255 FM* 951 405
TT system DEHNventil DV M TT 255 FM* 951 315
Data interface
Two pairs, even with different operating BLITZDUCTOR BXTU ML4 BD 0-180 920 349
voltages up to 180 V + BXT BAS base part + 920 300
Functional earthing/External lightning protection system
Functional equipotential bonding UNI earthing clamp 540 250
Air-termination rod with 101 000
Air-termination system
concrete base (8.5 kg) + 102 075
Figure 13 Building with external LPS and sufficient separation distance situation B (Supplement 5 of the DIN EN 62305-3 standard)

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that an additional type 2 d.c. arrester be installed on the

module side if the distance between the inverter input and
the PV generator exceeds 10 m.
The a.c. outputs of the inverters are sufficiently protected if the
distance between the PV inverters and the place of installation
of the type 2 arrester at the grid connection point (low-voltage
infeed) is less than 10 m. In case of greater cable lengths,
an additional type 2 surge protective device, for example
DEHNguard M275, must be installed upstream of the a.c.
input of the inverter as per CENELEC CLC/TS 50539-12.
Moreover, a type 2 DEHNguard MCI 275 (FM) surge pro-
tective device must be installed upstream of the meter of
the low-voltage infeed. CI (Circuit Interruption) stands for a
coordinated fuse integrated in the protective path of the ar-
Figure 14 Determination of the protected volume using the protec- rester, allowing the arrester to be used in the a.c. circuit with-
tive angle method out additional backup fuse. DEHNguard MCI 275 (FM)
is available for every low-voltage system configuration
(TN-C, TN-S, TT).
Application examples: If inverters are connected to data and sensor lines to moni-
Building without external lightning protection tor the yield, suitable surge protective devices are required.
system (situation A) BLITZDUCTOR XTU, which features terminals for two pairs,
Figure 12 shows the surge protection concept for a PV sys- for example for incoming and outgoing data lines, can be
used for data systems based on RS 485.
tem installed on a building without external lightning pro-
tection system. Dangerous surges enter the PV system due
Building with external lightning protection system
to inductive coupling resulting from nearby lightning strikes
and sufficient separation distance s (situation B)
or travel from the power supply system through the service
Figure 13 shows the surge protection concept for a PV sys-
entrance to the consumers installation. Type 2 SPDs are to
tem with external lightning protection system and sufficient
be installed at the following locations: separation distance s between the PV system and the exter-
d.c. side of the modules and inverters nal lightning protection system.
a.c. output of the inverter The primary protection goal is to avoid damage to persons
and property (building fire) resulting from a lightning strike.
Main low-voltage distribution board
In this context, it is important that the PV system does not
Wired communication interfaces interfere with the external lightning protection system.
Moreover, the PV system itself must be protected from di-
Every d.c. input (MPP) of the inverter must be protected by rect lightning strikes. This means that the PV system must
a type 2 surge protective device, for example DEHNguard M be installed in the protected volume of the external light-
YPV SCI (FM), that reliably protects the d.c. side of PV ning protection system. This protected volume is formed by
systems. The CENELEC CLC/TS 50539-12 standard requires air-termination systems (e.g. air-termination rods) which
prevent direct lightning strikes to
the PV modules and cables. The
separation distance
s rolling sphere radius pro- protective angle method (Fig-
air-termi- tective ure 14) or rolling sphere method
depending on angle
nation rod
the class of LPS (Figure 15) as described in sub-
section 5.2.2 of the IEC 62305-3
(EN 62305-3) standard may be
used to determine this protected
volume. A certain separation
distance s must be maintained
between all conductive parts of
the PV system and the lightning
Figure 15 Rolling sphere method versus protective angle method for determining the protected volume protection system. In this context,

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tomatically detects the operating voltage of the useful sig-

nal and adjusts the voltage protection level to this operating
voltage.

High-voltage-resistant, insulated HVI Conductor

Another possibility to maintain the separation distance s
is to use high-voltage-resistant, insulated HVI Conductors
which allow to maintain a separation distance s up to 0.9 m
in air. HVI Conductors may directly contact the PV system
downstream of the sealing end range. More detailed infor-
mation on the application and installation of HVI Conduc-
tors is provided in this Lightning Protection Guide or in the
relevant installation instructions.

Building with external lightning protection system

with insufficient separation distance s (situation C)
If the roofing is made of metal or is formed by the PV sys-
Figure 16 DEHNcube YPV SCI 1000 1M type 2 arrester for protecting tem itself, the separation distance s cannot be maintained.
inverters (1 MPPT) The metal components of the PV mounting system must
be connected to the external lightning protection system
in such a way that they can carry lightning currents (cop-
core shadows must be prevented by, for example, maintain- per conductor with a cross-section of at least 16 mm2 or
ing a sufficient distance between the air-termination rods equivalent). This means that lightning equipotential bond-
and the PV module. ing must also be implemented for the PV lines entering the
Lightning equipotential bonding is an integral part of a building from the outside (Figure 17). According to Sup-
lightning protection system. It must be implemented for all plement 5 of the German DIN EN 62305-3 standard and the
conductive systems and lines entering the building which CENELEC CLC/TS 50539-12 standard, d.c. lines must be pro-
may carry lightning currents. This is achieved by directly con- tected by a type 1 SPD for PV systems.
necting all metal systems and indirectly connecting all en- For this purpose, a type 1 and type 2 DEHNcombo YPV SCI (FM)
ergised systems via type 1 lightning current arresters to the combined arrester is used. Lightning equipotential bond-
earth-termination system. Lightning equipotential bonding ing must also be implemented in the low-voltage infeed. If
should be implemented as close as possible to the entrance the PV inverter(s) is (are) situated more than 10 m from the
point into the building to prevent partial lightning currents type 1 SPD installed at the grid connection point, an ad-
from entering the building. The grid connection point must ditional type 1 SPD must be installed on the a.c. side of the
be protected by a multipole spark-gap-based type 1 SPD, inverter(s) (e.g. type 1 + type 2 DEHNshield ... 255 combined
for example a type 1 DEHNventil M 255 combined ar- arrester). Suitable surge protective devices must also be in-
rester. This arrester combines a lightning current arrester stalled to protect the relevant data lines for yield monitor-
and a surge arrester in a single device. If the cable lengths ing. BLITZDUCTOR XTU surge protective devices are used to
between the arrester and the inverter are less than 10 m, protect data systems, for example based on RS 485.
sufficient protection is provided. In case of greater cable
lengths, additional type 2 DEHNguard M surge protective PV systems with microinverters
devices must be installed upstream of the a.c. input of the Microinverters require a different surge protection concept.
inverters as per CENELEC CLC/TS 50539-12. To this end, the d.c. line of a module or a pair of modules is
Every d.c. input of the inverter must be protected by a type 2 directly connected to the small-sized inverter. In this process,
PV arrester, for example DEHNcube YPV SCI (Figure 16). unnecessary conductor loops must be avoided. Inductive
This also applies to transformerless devices. If the invert- coupling into such small d.c. structures typically only has a
ers are connected to data lines, for example to monitor the low energetic destruction potential. The extensive cabling
yield, surge protective devices must be installed to protect of a PV system with microinverters is located on the a.c.
data transmission. For this purpose, BLITZDUCTOR XTU side (Figure 18). If the microinverter is directly fitted at the
with actiVsense technology can be provided for lines with module, surge protective devices may only be installed on
analogue signal and data bus systems such as RS485. It au- the a.c. side:

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separation
distance
not kept
<s

GJB 16 mm2 Cu
PC
=
~

M M DNO Distribution network operator

GJB Generator junction box
DNO M Meter
SEB MEB Main earthing busbar
MEB s Separation distance
SEB Service entrance box

No. in Fig. SPD *FM = Floating remote signalling contact Part No.
d.c. input of the inverter
Per MPPT DEHNcombo DCB YPV SCI 1000 FM* 900 066
a.c. output of the inverter
TN-S system DEHNshield DSH TNS 255 941 400
Low-voltage input
TN-C system DEHNventil DV M TNC 255 FM* 951 305
TN-S system DEHNventil DV M TNS 255 FM* 951 405
TT system DEHNventil DV M TT 255 FM* 951 315
Data interface
Two pairs, even with different operating BLITZDUCTOR BXTU ML4 BD 0-180 920 349
voltages up to 180 V + BXT BAS base part + 920 300
Functional earthing/External lightning protection system
Functional equipotential bonding UNI earthing clamp 540 250
Air-termination rod with 101 000
Air-termination system
concrete base (8.5 kg) + 102 075
Figure 17 Building with external LPS and insufficient separation distance situation C (Supplement 5 of the DIN EN 62305-3 standard)

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a.c. box (interface

to cables laid on site)

a.c. power
connection
d.c.
= = = = = =
~ ~ ~ ~ ~ ~

a.c.

a.c. cables (interconnected)

factory-mounted cables cables laid on site

Figure 18 Example: Building without external lightning protection system; surge protection for a microinverter located in the connection box of
the on-site cables

Buildings without external lightning protection system microinverters and lightning current carrying type 1
= type 2 DEHNguard M275 arresters for alternat- DEHNventil M...255 arresters at the low-voltage infeed.
ing/three-phase current in close proximity to the micro- Independent of particular manufacturers, microinverters fea-
inverters and DEHNguard275 CI at the low-voltage ture data monitoring systems. If data is modulated to the
infeed. a.c. lines via the microinverters, a surge protective device
Buildings with external lightning protection system and (for example DEHNbox DBX KT BD) must be provided on the
sufficient separation distance s = type 2 arresters, for separate receiving units (data export/data processing). The
example DEHNguard M275, in close proximity to the same applies to interface connections with downstream bus
microinverters and lightning current carrying type 1 ar- systems and their voltage supply (e.g. Ethernet, ISDN).
resters at the low-voltage infeed, for example DEHNventil
M...255. Solar power generation systems are an integral part of to-
Buildings with external lightning protection system and days electrical systems. They should be equipped with ad-
insufficient separation distance s = type 1 arresters, for equate lightning current and surge arresters, thus ensuring
example DEHNshield255, in close proximity to the long-term faultless operation of these sources of electricity.

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

DEHNventil

DV M TNC 255 FM (951 305)

Prewired combined type 1 and type 2 spark-gap-based lightning current and surge arrester consisting of a base part and plug-in protection
modules
Maximum system availability due to RADAX Flow follow current limitation
Capable of protecting terminal equipment

Figure without obligation

Basic circuit diagram DV M TNC 255 FM Dimension drawing DV M TNC 255 FM

Modular combined lightning current and surge arrester for TN-C systems.
Type DV M TNC 255 FM
Part No. 951 305
SPD according to EN 61643-11 / IEC 61643-11 type 1 + type 2 / class I + class II
Energy coordination with terminal equipment ( 5 m) type 1 + type 2 + type 3
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage (UC) 264 V (50 / 60 Hz)
Lightning impulse current (10/350 s) [L1+L2+L3-PEN] (Itotal) 75kA
Specific energy [L1+L2+L3-PEN] (W/R) 1.40 MJ/ohms
Lightning impulse current (10/350 s) [L-PEN] (Iimp) 25kA
Specific energy [L-PEN] (W/R) 156.25 kJ/ohms
Nominal discharge current (8/20 s) [L-PEN]/[L1+L2+L3-PEN] (In) 25 / 75kA
Voltage protection level (UP) 1.5kV
Follow current extinguishing capability a.c. (Ifi) 50kArms
Follow current limitation / Selectivity no tripping of a 20 A gL/gG fuse up to 50 kArms (prosp.)
Response time (tA) 100ns
Max. backup fuse (L) up to IK = 50 kArms 315A gG
Max. backup fuse (L-L') 125A gG
Temporary overvoltage (TOV) (UT) Characteristic 440 V / 120 min. withstand
Operating temperature range [parallel] / [series] (TU) -40 C ... +80 C / -40 C ... +60 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (L1, L1', L2, L2', L3, L3', PEN, 9) (min.) 10 mm solid / flexible
2 2
Cross-sectional area (L1, L2, L3, PEN) (max.) 50 mm stranded / 35 mm flexible
2 2
Cross-sectional area (L1', L2', L3', 9) (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 6module(s), DIN 43880
Approvals KEMA, VDE, UL, VdS
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Use in switchgear installations with prospective short-circuit
Extended technical data: currents of more than 50 kArms (tested by the German VDE)
Max. prospective short-circuit current 100 kArms (220 kApeak)
Limitation / Extinction of mains follow currents up to 100 kArms (220 kApeak)
Max. backup fuse (L) up to IK = 100 kArms 315A gL/gG
Weight 962g
Customs tariff number 85363030
GTIN 4013364108141
PU 1pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

DEHNventil

DV M TT 255 FM (951 315)

Prewired spark-gap-based type 1 and type 2 combined lightning current and surge arrester consisting of a base part and plug-in protection
modules
Maximum system availability due to RADAX Flow follow current limitation
Capable of protecting terminal equipmen

Figure without obligation

Basic circuit diagram DV M TT 255 FM Dimension drawing DV M TT 255 FM

Modular combined lightning current and surge arrester for TT and TN-S systems ("3+1" circuit).
Type DV M TT 255 FM
Part No. 951 315
SPD according to EN 61643-11 / IEC 61643-11 type 1 + type 2 / class I + class II
Energy coordination with terminal equipment ( 5 m) type 1 + type 2 + type 3
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage [L-N] (UC) 264 V (50 / 60 Hz)
Max. continuous operating a.c. voltage [N-PE] (UC (N-PE)) 255 V (50 / 60 Hz)
Lightning impulse current (10/350 s) [L1+L2+L3+N-PE] (Itotal) 100kA
Specific energy [L1+L2+L3+N-PE] (W/R) 2.50 MJ/ohms
Lightning impulse current (10/350 s) [L-N]/[N-PE] (Iimp) 25 / 100kA
Specific energy [L-N]/[N-PE] (W/R) 156.25 kJ/ohms / 2.50 MJ/ohms
Nominal discharge current (8/20 s) [L-N]/[N-PE] (In) 25 / 100kA
Voltage protection level [L-N]/[N-PE] (UP) 1.5 / 1.5 kV
Follow current extinguishing capability [L-N]/[N-PE] (Ifi) 50 kArms / 100 Arms
Follow current limitation / Selectivity no tripping of a 20 A gL/gG fuse up to 50 kArms (prosp.)
Response time (tA) 100ns
Max. backup fuse (L) up to IK = 50 kArms 315A gG
Max. backup fuse (L-L') 125A gG
Temporary overvoltage (TOV) [L-N] (UT) Characteristic 440 V / 120 min. withstand
Temporary overvoltage (TOV) [N-PE] (UT) Characteristic 1200 V / 200 ms withstand
Operating temperature range [parallel] / [series] (TU) -40 C ... +80 C / -40 C ... +60 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (L1, L1', L2, L2', L3, L3', N, N', PE, 9) (min.) 10 mm solid / flexible
2 2
Cross-sectional area (L1, L2, L3, N, PE) (max.) 50 mm stranded / 35 mm flexible
2 2
Cross-sectional area (L1', L2', L3', N', 9) (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 8module(s), DIN 43880
Approvals KEMA, VDE, UL, VdS
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Use in switchgear installations with prospective short-circuit
Extended technical data: currents of more than 50 kArms (tested by the German VDE)
Max. prospective short-circuit current 100 kArms (220 kApeak)
Limitation / Extinction of mains follow currents up to 100 kArms (220 kApeak)
Max. backup fuse (L) up to IK = 100 kArms 315A gL/gG
Weight 1,28kg
Customs tariff number 85363030
GTIN 4013364108189
PU 1pc(s)

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DEHNventil

DV M TNS 255 FM (951 405)

Prewired spark-gap-based type 1 and type 2 combined lightning current and surge arrester consisting of a base part and plug-in protection
modules
Maximum system availability due to RADAX Flow follow current limitation
Capable of protecting terminal equipment

Figure without obligation

Basic circuit diagram DV M TNS 255 FM Dimension drawing DV M TNS 255 FM

Modular combined lightning current and surge arrester for TN-S systems.
Type DV M TNS 255 FM
Part No. 951 405
SPD according to EN 61643-11 / IEC 61643-11 type 1 + type 2 / class I + class II
Energy coordination with terminal equipment ( 5 m) type 1 + type 2 + type 3
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage (UC) 264 V (50 / 60 Hz)
Lightning impulse current (10/350 s) [L1+L2+L3+N-PE] (Itotal) 100kA
Specific energy [L1+L2+L3+N-PE] (W/R) 2.50 MJ/ohms
Lightning impulse current (10/350 s) [L, N-PE] (Iimp) 25kA
Specific energy [L,N-PE] (W/R) 156.25 kJ/ohms
Nominal discharge current (8/20 s) [L/N-PE]/[L1+L2+L3+N-PE]
(In) 25 / 100kA
Voltage protection level [L-PE]/[N-PE] (UP) 1.5 / 1.5 kV
Follow current extinguishing capability a.c. (Ifi) 50kArms
Follow current limitation / Selectivity no tripping of a 20 A gL/gG fuse up to 50 kArms (prosp.)
Response time (tA) 100ns
Max. backup fuse (L) up to IK = 50 kArms 315A gG
Max. backup fuse (L-L') 125A gG
Temporary overvoltage (TOV) [L-N] (UT) Characteristic 440 V / 120 min. withstand
Operating temperature range [parallel] / [series] (TU) -40 C ... +80 C / -40 C ... +60 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (L1, L1', L2, L2', L3, L3', N, N', PE, 9) (min.) 10 mm solid / flexible
2 2
Cross-sectional area (L1, L2, L3, N, PE) (max.) 50 mm stranded / 35 mm flexible
2 2
Cross-sectional area (L1', L2', L3', N', 9) (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 8module(s), DIN 43880
Approvals KEMA, VDE, UL, VdS
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Use in switchgear installations with prospective short-circuit
Extended technical data: currents of more than 50 kArms (tested by the German VDE)
Max. prospective short-circuit current 100 kArms (220 kApeak)
Limitation / Extinction of mains follow currents up to 100 kArms (220 kApeak)
Max. backup fuse (L) up to IK = 100 kArms 315A gL/gG
Weight 1,36kg
Customs tariff number 85363030
GTIN 4013364108165
PU 1pc(s)

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DEHNcombo

DCB YPV SCI 1000 FM (900 066)

Prewired type 1 and type 2 combined lightning current and surge arrester for use in photovoltaic generator circuits
Combined disconnection and short-circuiting device with safe electrical isolation prevents fire damage caused by d.c. switching arcs (patented
SCI principle)
Space-saving enclosure with a width of four modules

Figure without obligation

Basic circuit diagram DCB YPV SCI 1000 FM Dimension drawing DCB YPV SCI 1000 FM
Combined lightning current and surge arrester for use in photovoltaic power supply systems up to 1000 V d.c.; with floating remote signalling
contact.
Type DCB YPV SCI 1000 FM
Part No. 900 066
SPD according to EN 50539-11 type 1 + type 2
Max. PV voltage [DC+ -> DC-] (UCPV) 1000V
Max. PV voltage [DC+/DC- -> PE] (UCPV) 725V
Short-circuit current rating (ISCPV) 1000A
Nominal discharge current (8/20 s) (In) 15kA
Total discharge current (8/20 s) [DC+/DC- -> PE] (Itotal) 30kA
Total discharge current (10/350 s) [DC+/DC- -> PE] (Itotal) 12.5kA
Specific energy [DC+/DC- -> PE] (l) 39.06kJ/ohms
Lightning impulse current (10/350 s) [DC+ -> PE/DC- -> PE] (Iimp) 6.25kA
Specific energy [DC+ -> PE/DC- -> PE] (W/R) 9.76kJ/ohms
Voltage protection level [(DC+/DC-) -> PE] (UP) 2.5kV
Voltage protection level [DC+ -> DC-] (UP) 4.75kV
Response time (tA) 25ns
Operating temperature range (TU) -40 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 1,5 mm solid / flexible
2 2
Cross-sectional area (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Dimensions 4module(s), DIN 43880
Approvals KEMA
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Weight 437g
Customs tariff number 85363030
GTIN 4013364153738
PU 1pc(s)

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DEHNshield

DSH TNS 255 (941 400)

Application-optimised and prewired type 1 and type 2 spark-gap-based combined lightning current and surge arrester
Space-saving arrester for compact and simply equipped electrical installations with reduced technical requirements
Capable of protecting terminal equipment

Figure without obligation

Basic circuit diagram DSH TNS 255 Dimension drawing DSH TNS 255
Application-optimised and prewired combined lightning current and surge arrester for TN-S systems.
Type DSH TNS 255
Part No. 941 400
SPD according to EN 61643-11 / IEC 61643-11 type 1 + type 2 / class I + class II
Energy coordination with terminal equipment ( 5 m) type 1 + type 2 + type 3
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage (UC) 255 (50 / 60 Hz)
Lightning impulse current (10/350 s) [L1+L2+L3+N-PE] (Itotal) 50kA
Specific energy [L1+L2+L3+N-PE] (W/R) 625.00kJ/ohms
Lightning impulse current (10/350 s) [L, N-PE] (Iimp) 12.5kA
Specific energy [L,N-PE] (W/R) 39.06kJ/ohms
Nominal discharge current (8/20 s) [L/N-PE]/[L1+L2+L3+N-PE]
(In) 12.5 / 50kA
Voltage protection level [L-PE]/[N-PE] (UP) 1.5 / 1.5 kV
Follow current extinguishing capability a.c. (Ifi) 25kArms
Follow current limitation / Selectivity no tripping of a 32 A gL/gG fuse up to 25 kArms (prosp.)
Response time (tA) 100ns
Max. mains-side overcurrent protection 160A gL/gG
Temporary overvoltage (TOV) [L-N] (UT) Characteristic 440 V / 120 min. withstand
Operating temperature range (TU) -40 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (L1, L2, L3, N, PE, 9) (min.) 1.5 mm solid / flexible
2 2
Cross-sectional area (L1, L2, L3, N, PE, 9) (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 4module(s), DIN 43880
Approvals KEMA, VDE, UL
Weight 525g
Customs tariff number 85363030
GTIN 4013364133563
PU 1pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

DEHNcube

DCU YPV SCI 1000 1M (900 910)

Prewired multipole surge arrester with IP 65 degree of protection for photovoltaic systems
Combined disconnection and short-circuiting device with safe electrical isolation in the protection module prevents fire damage caused by d.c.
switching arcs (patented SCI principle)
Easy and fast implementation of surge protection measures since no space is required in a separate insulating enclosure

Figure without obligation

Basic circuit diagram DCU YPV SCI 1000 1M Dimension drawing DCU YPV SCI 1000 1M
Multipole surge arrester with three-step d.c. switching device for PV inverters with one MPP input.

Type DCU YPV SCI 1000 1M

Part No. 900 910
SPD according to EN 50539-11 type 2
Max. PV voltage (UCPV) 1000V
Short-circuit withstand capability (ISCPV) 1000A
Total discharge current (8/20 s) (Itotal) 40kA
Nominal discharge current (8/20 s) [(DC+/DC-) --> PE ] (In) 12.5kA
Max. discharge current (8/20 s) [(DC+/DC-) --> PE] (Imax) 25kA
Voltage protection level (UP) 4kV
Voltage protection level at 5 kA (UP) 3.5kV
Response time (tA) 25ns
Operating temperature range (TU) -35 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 2.5 mm solid / flexible
2
Cross-sectional area (max.) 6 mm solid / flexible
Place of installation outdoor
Degree of protection IP 65
Type with pressure compensating element
Cover transparent cover with product label
Colour of enclosure grey
Number of cable entries 3x 3-7 mm
Enclosure dimensions (w x h x d) 94 x 94 x 81mm
Approvals KEMA
Weight 426g
Customs tariff number 85363030
GTIN 4013364155046
PU 1pc(s)

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DEHNcube

DCU YPV SCI 1000 2M (900 920)

Prewired multipole surge arrester with IP 65 degree of protection for photovoltaic systems
Combined disconnection and short-circuiting device with safe electrical isolation in the protection module prevents fire damage caused by d.c.
switching arcs (patented SCI principle)
Easy and fast implementation of surge protection measures since no space is required in a separate insulating enclosure

Figure without obligation

Basic circuit diagram DCU YPV SCI 1000 2M Dimension drawing DCU YPV SCI 1000 2M
Multipole surge arrester with three-step d.c. switching device for PV inverters with two MPP inputs.
Type DCU YPV SCI 1000 2M
Part No. 900 920
SPD according to EN 50539-11 type 2
Max. PV voltage (UCPV) 1000V
Short-circuit withstand capability (ISCPV) 1000A
Total discharge current (8/20 s) (Itotal) 40kA
Nominal discharge current (8/20 s) [(DC+/DC-) --> PE ] (In) 12.5kA
Max. discharge current (8/20 s) [(DC+/DC-) --> PE] (Imax) 25kA
Voltage protection level (UP) 4kV
Voltage protection level at 5 kA (UP) 3.5kV
Response time (tA) 25ns
Operating temperature range (TU) -35 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 2.5 mm solid / flexible
2
Cross-sectional area (max.) 6 mm solid / flexible
Place of installation outdoor
Degree of protection IP 65
Type with pressure compensating element
Cover transparent cover with product label
Colour of enclosure grey
Number of cable entries 5x 3-7 mm
Enclosure dimensions (w x h x d) 130 x 94 x 81mm
Approvals KEMA
Weight 617g
Customs tariff number 85363030
GTIN 4013364155053
PU 1pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

DEHNguard

DG M TNC CI 275 FM (952 309)

Arrester backup fuse integrated in the protection module
Prewired complete unit consisting of a base part and plug-in protection modules
High reliability due to "Thermo Dynamic Control" SPD monitoring device

Figure without obligation

Basic circuit diagram DG M TNC CI 275 FM Dimension drawing DG M TNC CI 275 FM

Modular surge arrester with integrated backup fuses for TN-C systems.
Type DG M TNC CI 275 FM
Part No. 952 309
SPD according to EN 61643-11 / IEC 61643-11 type 2 / class II
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage (UC) 275 V (50 / 60 Hz)
Nominal discharge current (8/20 s) (In) 12.5kA
Max. discharge current (8/20 s) (Imax) 25kA
Voltage protection level (UP) 1.5kV
Voltage protection level at 5 kA (UP) 1kV
Response time (tA) 25ns
Max. mains-side overcurrent protection not required
Rated breaking capacity of the internal backup protection 25kA
Short-circuit withstand capability (ISCCR) 25kArms
Temporary overvoltage (TOV) (UT) Characteristic 335 V / 5 sec. withstand
Temporary overvoltage (TOV) (UT) Characteristic 440 V / 120 min. safe failure
Operating temperature range (TU) -40 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 1.5 mm solid / flexible
2 2
Cross-sectional area (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 3 module(s), DIN 43880
Approvals KEMA, VDE
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Weight 382g
Customs tariff number 85363030
GTIN 4013364128378
PU 1pc(s)

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DEHNguard

DG M TT CI 275 FM (952 327)

Arrester backup fuse integrated in the protection module
Prewired complete unit consisting of a base part and plug-in protection modules
High reliability due to "Thermo Dynamic Control" SPD monitoring device

Figure without obligation

Dimension drawing DG M TT CI 275 FM

Basic circuit diagram DG M TT CI 275 FM

Modular surge arrester with integrated backup fuses for TT and TN-S systems ("3+1" circuits).
Type DG M TT CI 275 FM
Part No. 952 327
SPD according to EN 61643-11 / IEC 61643-11 type 2 / class II
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage [L-N] (UC) 275 V (50 / 60 Hz)
Max. continuous operating a.c. voltage [N-PE] (UC) 255 V (50 / 60 Hz)
Nominal discharge current (8/20 s) [L-N] (In) 12.5kA
Nominal discharge current (8/20 s) [N-PE] (In) 20kA
Max. discharge current (8/20 s) [L-N] (Imax) 25kA
Max. discharge current (8/20 s) [N-PE] (Imax) 40kA
Lightning impulse current (10/350 s) [N-PE] (Iimp) 12kA
Voltage protection level [L-N] (UP) 1.5kV
Voltage protection level [L-N] at 5 kA (UP) 1kV
Voltage protection level [N-PE] (UP) 1.5kV
Follow current extinguishing capability [N-PE] (Ifi) 100Arms
Response time [L-N] (tA) 25ns
Response time [N-PE] (tA) 100ns
Max. mains-side overcurrent protection not required
Rated breaking capacity of the internal backup protection 25kA
Short-circuit withstand capability (ISCCR) 25kArms
Temporary overvoltage (TOV) [L-N] (UT) Characteristic 335 V / 5 sec. withstand
Temporary overvoltage (TOV) [L-N] (UT) Characteristic 440 V / 120 min. safe failure
Temporary overvoltage (TOV) [N-PE] (UT) Characteristic 1200 V / 200 ms withstand
Operating temperature range (TU) -40 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 1.5 mm solid / flexible
2 2
Cross-sectional area (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 4 module(s), DIN 43880
Approvals KEMA, VDE
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Weight 475g
Customs tariff number 85363030
GTIN 4013364128392
PU 1pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

DEHNguard

DG M TNS 275 FM (952 405)

Prewired complete unit consisting of a base part and plug-in protection modules
High discharge capacity due to heavy-duty zinc oxide varistors / spark gaps
High reliability due to "Thermo Dynamic Control" SPD monitoring device

Figure without obligation

Basic circuit diagram DG M TNS 275 FM Dimension drawing DG M TNS 275 FM

Modular surge arrester for use in TN-S systems; with floating changeover contact.
Type DG M TNS 275 FM
Part No. 952 405
SPD according to EN 61643-11 / IEC 61643-11 type 2 / class II
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage (UC) 275 V (50 / 60 Hz)
Nominal discharge current (8/20 s) (In) 20kA
Max. discharge current (8/20 s) (Imax) 40kA
Voltage protection level (UP) 1.5kV
Voltage protection level at 5 kA (UP) 1kV
Response time (tA) 25ns
Max. mains-side overcurrent protection 125A gG
Short-circuit withstand capability for max. mains-side overcurrent
protection (ISCCR) 50kArms
Temporary overvoltage (TOV) (UT) Characteristic 335 V / 5 sec. withstand
Temporary overvoltage (TOV) (UT) Characteristic 440 V / 120 min. safe failure
Operating temperature range (TU) -40 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 1.5 mm solid / flexible
2 2
Cross-sectional area (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 4module(s), DIN 43880
Approvals KEMA, VDE, UL, VdS
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Weight 453g
Customs tariff number 85363030
GTIN 4013364108462
PU 1pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

DEHNguard

DG M TNS CI 275 FM (952 406)

Arrester backup fuse integrated in the protection module
Prewired complete unit consisting of a base part and plug-in protection modules
High reliability due to "Thermo Dynamic Control" SPD monitoring device

Figure without obligation

Basic circuit diagram DG M TNS CI 275 FM Dimension drawing DG M TNS CI 275 FM

Modular surge arrester with integrated backup fuses for TN-S systems.
Type DG M TNS CI 275 FM
Part No. 952 406
SPD according to EN 61643-11 / IEC 61643-11 type 2 / class II
Nominal a.c. voltage (UN) 230 / 400 V (50 / 60 Hz)
Max. continuous operating a.c. voltage (UC) 275 V (50 / 60 Hz)
Nominal discharge current (8/20 s) (In) 12.5kA
Max. discharge current (8/20 s) (Imax) 25kA
Voltage protection level (UP) 1.5kV
Voltage protection level at 5 kA (UP) 1kV
Response time (tA) 25ns
Max. mains-side overcurrent protection not required
Rated breaking capacity of the internal backup protection 25kA
Short-circuit withstand capability (ISCCR) 25kArms
Temporary overvoltage (TOV) (UT) Characteristic 335 V / 5 sec. withstand
Temporary overvoltage (TOV) (UT) Characteristic 440 V / 120 min. safe failure
Operating temperature range (TU) -40 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 1.5 mm solid / flexible
2 2
Cross-sectional area (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 4module(s), DIN 43880
Approvals KEMA, VDE
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Weight 473g
Customs tariff number 85363030
GTIN 4013364128354
PU 1pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

DEHNguard

DG M YPV SCI 1000 FM (952 515)

Prewired modular complete unit for use in photovoltaic systems consisting of a base part and plug-in protection modules
Combined disconnection and short-circuiting device with safe electrical isolation in the protection module prevents fire damage caused by d.c.
switching arcs (patented SCI principle)
Safe replacement of protection modules without arc formation due to integrated d.c. fuses

Figure without obligation

Basic circuit diagram DG M YPV SCI 1000 FM Dimension drawing DG M YPV SCI 1000 FM
Modular multipole surge arrester with three-step d.c. switching device for use in PV systems with remote signalling contact (floating changeover
contact).
Type DG M YPV SCI 1000 FM
Part No. 952 515
SPD according to EN 50539-11 Type 2
Max. PV voltage (UCPV) 1000V
Short-circuit current rating (ISCPV) 1000A
Total discharge current (8/20 s) (Itotal) 40kA
Nominal discharge current (8/20 s) [(DC+/DC-) --> PE] (In) 12.5kA
Max. discharge current (8/20 s) [(DC+/DC-) --> PE] (Imax) 25kA
Voltage protection level (UP) 4kV
Voltage protection level at 5 kA (UP) 3.5kV
Response time (tA) 25ns
Operating temperature range (TU) -40 C ... +80 C
Operating state / fault indication green / red
Number of ports 1
2
Cross-sectional area (min.) 1.5 mm solid / flexible
2 2
Cross-sectional area (max.) 35 mm stranded / 25 mm flexible
For mounting on 35 mm DIN rails acc. to EN 60715
Enclosure material thermoplastic, red, UL 94 V-0
Place of installation indoor installation
Degree of protection IP 20
Capacity 3module(s), DIN 43880
Approvals KEMA, UL, CSA
Type of remote signalling contact changeover contact
a.c. switching capacity 250 V / 0.5 A
d.c. switching capacity 250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
2
Cross-sectional area for remote signalling terminals max. 1.5 mm solid / flexible
Weight 323g
Customs tariff number 85363030
GTIN 4013364126435
PU 1pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

BLITZDUCTOR XTU

BXTU ML4 BD 0-180 (920 349)

Universal voltage type with actiVsense technology
For installation in conformity with the lightning protection zone concept at the boundaries from 0A 2 and higher
With integrated LifeCheck monitoring

Figure without obligation

Basic circuit diagram BXTU ML4 BD 0-180 Diagram of the voltage protection level BXTU
Space-saving combined lightning current and surge arrester module with actiVsense and LifeCheck technology for protecting two pairs with the
same or a different operating voltage of galvanically isolated balanced interfaces. Automatically detects the operating voltage of the useful signal and
optimally adapts the voltage protection level to it.
Type BXTU ML4 BD 0-180
Part No. 920 349
SPD class M
SPD monitoring system LifeCheck
Operating voltage (UN) 0-180V
Frequency of the operating voltage (fUN) 0-400Hz
Max. continuous operating d.c. voltage (UC) 180V
Max. continuous operating a.c. voltage (UC) 127V
Permissible superimposed signal voltage (Usignal) +/- 5V
Cut-off frequency line-line (Usignal, balanced 100 ohms) (fG) 50MHz
Nominal current at 80 C (equal to max. short-circuit current) (IL) 100mA
D1 Total lightning impulse current (10/350 s) (Iimp) 10kA
D1 Lightning impulse current (10/350 s) per line (Iimp) 2.5kA
C2 Total nominal discharge current (8/20 s) (In) 20kA
C2 Nominal discharge current (8/20 s) per line (In) 10kA
Voltage protection level line-line for In C2 (Up) see diagram, line C2
Voltage protection level line-line at 1 kV/s C3 (Up) see diagram, line C3
Voltage protection level line-line for Iimp D1 (Up) UN + 53 V
Voltage protection level line-PG for C2/C3/D1 550V
Series resistance per line 10 ohms; typically 7.5ohms
Capacitance line-line (C) 80 pF
Capacitance line-PG (C) 16 pF
Operating temperature range (TU) -40 C ... +80 C
Degree of protection (plugged-in) IP 20
Pluggable into BXT BAS / BSP BAS 4 base part
Earthing via BXT BAS / BSP BAS 4 base part
Enclosure material polyamide PA 6.6
Colour yellow
Test standards IEC 61643-21 / EN 61643-21, UL 497B
)
SIL classification up to SIL3 *
Approvals CSA, UL, GOST
Weight 25g
Customs tariff number 85363010
GTIN 4013364126404
PU 1pc(s)

)
* For more detailed information, please visit www.dehn-international.com.

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

BLITZDUCTOR

BXT BAS (920 300)

Four-pole version for universal use with all types of BSP and BXT / BXTU protection modules
No signal interruption if the protection module is removed
Universal design without protection elements

Figure without obligation

Basic circuit diagram with and without plugged-in module Dimension drawing BXT BAS
The BLITZDUCTOR XT base part is a very space-saving and universal four-pole feed-through terminal for the insertion of a protection module without
signal interruption if the protection module is removed. The snap-in mechanism at the supporting foot of the base part allows the protection module
to be safely earthed via the DIN rail. Since no components of the protective circuit are situated in the base part, only the protection modules must be
maintained.
Type BXT BAS
Part No. 920 300
Operating temperature range (TU) -40 C ... +80 C
Degree of protection IP 20
For mounting on 35 mm DIN rails acc. to EN 60715
Connection (input / output) screw / screw
Signal disconnection no
2
Cross-sectional area, solid 0.08-4 mm
2
Cross-sectional area, flexible 0.08-2.5 mm
Tightening torque (terminals) 0.4 Nm
Earthing via 35 mm DIN rails acc. to EN 60715
Enclosure material polyamide PA 6.6
Colour yellow
)
ATEX approvals DEKRA 11ATEX0089 X: II 3 G Ex nA IIC T4 Gc *
)
IECEx approvals DEK 11.0032X: Ex nA IIC T4 Gc *
Approvals CSA, VdS, UL, GOST
Weight 34g
Customs tariff number 85369010
GTIN 4013364109179
PU 1pc(s)
)
* only in connection with an approved protection module

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

Air-termination rod

FS 10 1000 AL (101 000)

Figure without obligation

Air-termination rod chamfered on both sides, for protecting roof-mounted structures, chimneys etc., also for erection with concrete base (8.5 kg) for
wedge mounting or for fixing with rod holders / spacers.
Part No. 101 000
Total length (l1) 1000mm
Material Al
Diameter 10mm
Standard EN 62561-2
Weight 212g
Customs tariff number 85389099
GTIN 4013364094505
PU 20pc(s)

Concrete base

BES 8.5KG KT10 16 D240 SET (102 075)

Figure without obligation

Concrete bases for air-termination rods 10 mm (length 1000 mm), protecting small-sized roof-mounted structures on flat roofs and for installing
spacers, e.g. for isolated ring conductors with DEHNiso spacers 16 mm, length up to 675 mm (distance 0.8 m).
Part No. 102 075
Type stackable
Support wedge mounting 10 / 16 mm
Diameter 240mm
Material concrete (C45/55)
Material of wedge StSt
Weight 8,46kg
Customs tariff number 85389099
GTIN 4013364094215
PU 120pc(s)

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 White Paper: Lightning and surge protection for rooftop photovoltaic systems

Earthing clamp

te
s ted
UEK 8.10 AQ4 50 HKSM8 V2A (540 250)

Figure without obligation

Earthing clamps for integrating mounting systems e.g. of PV installations into the functional equipotential bonding/functional earthing (optionally black
conductor) and lightning equipotential bonding according to IEC/EN 62305-3.

The StSt contact plate (intermediate element) allows for different materials of conductors (Cu, Al, St/tZn and StSt ) to be connected to the usual
mounting systems, e.g. to aluminium, without the risk of contact corrosion.
The double cleat design allows for easy and quick interconnection of the profiles, e.g. by feed-through wiring.
Part No. 540 250
Material of clamp StSt
Clamping range Rd 8-10mm
2
Connection (solid / stranded) 4-50mm
Screw hammer-head bolt M8 x 30mm
Self-locking nut width across flats 13mm
Material of screw / nut StSt
Standard EN 62561-1
Weight 60g
Customs tariff number 85389099
GTIN 4013364138650
PU 50pc(s)

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 www.dehn-international.com/partners

Surge Protection DEHN + SHNE Hans-Dehn-Str. 1 Tel. +49 9181 906-0

Lightning Protection GmbH + Co.KG. Postfach 1640 Fax +49 9181 906-1100
Safety Equipment 92306 Neumarkt info@dehn.de
DEHN protects. Germany www.dehn-international.com

www.dehn-international.com/partners

Type designations of products mentioned in the white paper being at the same time registered trademarks are not especially marked. So if there is no marking of or this does not
mean that the type designation is a free trade name. Neither it can be seen whether patents or utility models and other intellectual and industrial property rights are available. We reserve
the right to introduce changes in performance, configuration and technology, dimensions, weights and materials in the course of technical progress. The figures are shown without obligation.
Misprints, errors and modifications excepted. Reproduction in any form whatsoever is forbidden without our authorisation.
actiVsense, BLITZDUCTOR, BLITZPLANER, DEHN, DEHN Logo, DEHN schtzt, DEHNbloc, DEHNfix, DEHNgrip, DEHNguard, DEHNport, DEHNQUICK, DEHNrapid, DEHNshield, DEHNsnap,
DEHNventil, HVI, LifeCheck, Red/Line are protected by German Trade Mark, by Community Trade Mark (EU) and/or in other countries.

WP018/E/0615 Copyright 2015 DEHN + SHNE