OBO Bettermann A Series Guide

Mounting and installation information
for junction boxes
For any installation requirement in all kinds of
application areas

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Mounting and installation information for junction boxes

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Mounting and installation information for junction boxes
Contents
1. Installation in external areas, outdoors, in damp and wet
areas and rooms 5
1.1. Basic principles 5
1.2. Protection against UV radiation 5
1.3. Protection against high temperatures 6
1.4. Protection against chemical influences 6
1.5. Protection against condensation 6
1.6. Protection against rain/snow (precipitation) 7
1.7. Protection against water build-up (frost) 7
1.8. Protection against plants and/or mould growth 7
2. Protection ratings according to IEC 60529 (VDE 0470-1) 8
3. Overview of the installation areas 10
3.1. Protection against direct contact (basic protection) 10
3.2. Rooms with bath tubs or showers according to DIN VDE 0100-701 10
3.3. Pools of swimming baths or other pools according to DIN VDE 0100-702 11
3.4. Agricultural or horticultural facilities according to DIN VDE 0100-705 12
3.5. Damp and wet areas, rooms and outdoor areas according to
DIN VDE 0100-737 12
3.6. Photovoltaic systems according to DIN VDE 0100-712 13
3.7. Strain relief, cable systems VDE 0100-520 14
4. Junction boxes from OBO Bettermann 15
4.1. A series – the everyday hero 15
4.2. T series – the all-rounder 16
4.3. X series – the extreme athlete 17
4.4. Mx series – the robust one 18

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Mounting and installation information for junction boxes
Junction boxes are used to connect cables and can be
mounted in all kinds of areas. With regard to the ambient
conditions, several factors and standardised specifica-
tions must be taken into account, in order to select the
right junction box for the intended place of use. Thus,
with installations in outdoor areas or in damp or wet envir-
onments, it is necessary to estimate exactly how strong
the load from weathering or possibly damaging envir-
onmental influences is and which protective measures
are necessary. The division into different protection rat-
ings, also termed IP codes, provides information on how
strongly a junction box is protected against contact and
the harmful ingress of water. By contrast, the so-called IK
code represents the protection rating against mechanic-
al loads. DIN VDE 0100 is an erection requirement and
specifies which requirements a junction box must fulfil in
specific installation areas. To guarantee a safe device in-
stallation, all these factors must be checked in individual
cases and observed during the selection.
Introduction

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Mounting and installation information for junction boxes
1. Installation in external areas, outdoors, in damp and wet areas and rooms
1.1. Basic principles
With all installation types, the user must always comply
with the valid conditions, such as the erection require-
ments according to DIN VDE 0100-ff.
Depending on the local circumstances, the user may
need to take additional or special measures as protec-
tion, to guarantee the safe function of junction boxes.
UV radiation Condensation water
Heat radiation,
e.g. sun
Rain, snow
(precipitation)
Chemical influences Water build-up, frost
With outdoor installations, there is a wide
range of influencing factors
1.2. Protection against UV radiation
UV radiation can cause major structural damage to vari-
ous plastics. This damage may even lead to destruction.
For these reasons, products made of the material poly-
styrene (PS) may not be used in outdoor areas.
OBO Bettermann developed the junction boxes of the T
and X series for these applications. These products are
manufactured from materials offering a high level of re-
sistance to UV radiation.
T series X series

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Mounting and installation information for junction boxes
1.5. Protection against condensation
The tighter the connection sockets or distributor boxes
are closed, the greater the likelihood that condensation
will occur.
This is particularly the case in places where strong tem-
perature variations are to be expected. The formation of
condensation water is increased or amplified by the loss
of power of the electrical resources installed.
This can cause differing pressure conditions, which can
lead to the housing sucking in air when there is a change
in temperature. During a subsequent temperature in-
crease, the moisture located in the air precipitates as
water onto the cold surface of the housing, e.g. on the
cover.
As soon as this effect has occurred multiple times, a con-
siderable volume of water can collect in the housing. The
higher the protection level of the housing, the higher the
volume that can collect in the interior, as the water is no
longer discharged. This means that the tightness may
even have a negative impact and damage may occur.
According to DIN VDE 0100-520, measures must be
taken to remove water, if water or condensation can
occur within cable systems.
Depending on the type, OBO Bettermann's junction
boxes of the various product groups can offer a break-out
or condensation water opening to be pushed in. This is
attached in such a way that possible condensation can
flow out freely at any time, irrespective of whether the
box is mounted horizontally or vertically. Alternatively,
pressure compensation measures can be used, such as
the OBO pressure compensation element.
1.3. Protection against high temperatures
During operation, electrical devices require loss power.
This factor must always be observed, whilst taking the
ambient temperature and the installation type into ac-
count.
Switching device combinations are designed for ambi-
ent temperatures between –25 °C and +35 °C (over
a maximum period of 24 hours). Brief heating up to
+40 °C is not problematic. Even if OBO Bettermann
junction boxes are suitable for temperatures of –40 °C to
+80 °C, the manufacturer's specifications and the speci-
fications of the appropriate product safety standard must
be checked for the installed devices.
Sunlight or other heat sources can lead to improper in-
ner temperatures, which must be avoided at all costs.
Otherwise, the safe function of the electrical resources
may not be guaranteed.
According to VDE 0100-520, 522.1.2, cable systems, in-
cluding their accessories, may only be operated at ambi-
ent temperatures corresponding to the product standard
or the manufacturer's specifications and may not exceed
the limit values.
1.4. Protection against chemical influences
Installations in areas with an increased concentration of
pollutants in the area may see a restriction of suitability.
The X series from OBO Bettermann is resistant to min-
eral oils and various vegetable and animal fats.

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Mounting and installation information for junction boxes
1.6. Protection against rain/snow (precipitation)
The protection rating tests carried out according to IEC
60529 serve as comparative tests and to classify prop-
erties. These tests are limited to a few minutes and can-
not imitate weather through precipitation or cleaning with
a water jet. A general weather test cannot be defined
due to differing local circumstances. For this reason, the
erector requirements of the appropriate installation situ-
ation must always be taken into account.
According to DIN VDE 0100-520, 522.3.1, cable systems
must always be selected in such a way that damage from
condensation or the ingress of water cannot be caused.
This means that condensation water openings should be
available and the junction boxes in outdoor areas may
only be installed with protection.
1.8. Protection against plants and/or mould growth
The plastics used for electrical installations are organic
materials. For this reason, damage from plants, algae or
mould should be taken into account.
According to DIN VDE 0100-520, 522.9.1, if experience
has shown that plant and/or mould growth can cause
damage, the cable systems must be selected according-
ly or special protective measures must be provided.
Note: A routing type must be selected which allows a
corresponding removal of such growth.
Conclusion:
Taking the above-mentioned parameters into account,
protected installation of the junction boxes is essential
and also described in detail in the erection standards.
Only in this way can safe operation of the protection de-
vices be guaranteed.
Installation only in protected external areas
Please note that, in the case of an installation such
as under solar panels, the housings may not be lo-
cated directly under the joints of the solar modules,
or that the housings must additionally be covered
with protective covers.
1.7. Protection against water build-up (frost)
Frequently, with an installation that is not protected
against precipitation, water will collect on surfaces and
in recesses. If these cannot flow away unimpeded, then
this will cause a build-up of water. In the case of low tem-
peratures, this water can freeze and exert an improper
mechanical load on the housing. This can lead to dam-
age to the housings. Therefore, during installation, care
should be taken that the housings are protected by a
cover.
A cover may already exist due to structural circum-
stances, may be erected by the user or be created with
additional components.
Additional information on outdoor installation and
UV resistance:
The information on the protection rating and UV resist-
ance is frequently seen as the only criterion for outdoor
installation. In the case of outdoor installations, other
factors, such as absolute temperature, frequency of tem-
perature changes, humidity and particularly chemical in-
fluences, have a role to play. Besides influences through
UV impacts, with outdoor installations it is damage from
chemical influences, in particular, that are to be expected.
Thus, outdoor areas of petrol stations, chemical plants,
rubbish dumps, compressors, sewage works, etc. must
be investigated particularly critically in advance.

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Mounting and installation information for junction boxes
2. Protection ratings according to IEC 60529 (VDE 470-1)
The IP protection rating specifies how far a component
is protected against contact and foreign bodies and the
ingress of water. The IP protection ratings are controlled
by the standard DIN EN 60529 (VDE 0470 Part 1). The
IP is always made up of two digits.
The first digit designates the contact and foreign body
protection. On the one hand, it specifies how far a hous-
ing prevents access to dangerous parts, by preventing
or limiting the ingress of body parts or objects held by a
person. On the other hand, it specifies how far the hous-
ing protects the installed resources against the ingress of
solid foreign bodies.
The second digit specifies the protection against water.
It specifies how far the resource is protected against in-
coming water and the resulting damage.

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Mounting and installation information for junction boxes
Protection rating against contact and the ingress of foreign bodies
First code digit ...against access to the dangerous parts ...against solid foreign bodies
0 Protected against access to dangerous parts with the back of the hand Non-protected
1 Protected against access to hazardous parts with a finger Protected against solid foreign bodies
50 mm diameter and larger
2 Protected against access to hazardous parts with a tool Protected against solid foreign bodies
12.5 mm diameter and larger
3 Protected against access to hazardous parts with a wire Protected against solid foreign bodies
2.5 mm diameter and larger
4 Protected against access to hazardous parts with a wire Protected against solid foreign bodies
1.0 mm diameter and larger
5 Protected against access to hazardous parts with a wire Dust-protected
6 Protected against access to hazardous parts with a wire Dust-proof
Protection rating against the entry of water with a damaging impact
Second code digit Short name Definition
0 Non-protected -
1 Protected against water droplets Droplets falling vertically may have no damaging impact.
2 Protected against water drops
when enclosure tilted to up
to 15°
Vertically falling drops shall have no harmful effects when the enclosure is
tilted at any angle up to 15° on either side of the vertical.
3 Protected against spray water Water being sprayed at an angle of 60° on both sides of the vertical may not
have any damaging impact.
4 Protected against spray water Water spraying the housing from any direction may not have any damaging
impact.
5 Protected against water jets Jets of water pointing at the housing from any direction may not have any
damaging impact.
6 Protected against strong water
jets
Strong jets of water pointing at the housing from any direction may not have
any damaging impact.
7 Protected against the effects of
being temporarily immersed in
water
If the housing is sometimes underwater under standard pressure and time
conditions, then water may not enter in such volumes as would have a damag-
ing impact.
8 Protected against the effects of
being continuously immersed
in water
Ingress of water in quantities causing harmful effects shall not be possible
when the enclosure is continuously immersed in water under conditions which
shall be agreed between manufacturer and user. However, the conditions are
more difficult to fulfil than for number 7.

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Mounting and installation information for junction boxes
3. Overview of the installation areas
Various standard requirements must be fulfilled so that
junction boxes can be installed in specific environments
and that the internal installations do not present a safety
risk.
Example: Living rooms, hotel rooms, attics, etc. Areas in rooms with bathtub or shower
3.2. Rooms with bathtubs or showers according to
DIN VDE 0100-701
Rooms with bathtubs or showers are divided up into
areas, in which only certain devices may be installed.
Important protection requirements:
The following switching devices, control devices and in-
stallation devices are permitted in the areas:
Area 0
No devices permitted.
Area 1
• Junction boxes and connection boxes for the supply
of electrical consumables, which are permitted in
Areas 0 and 1 according to 701.55;
• Accessories, including sockets, of circuits protected
by low voltages using safety extra-low voltage (SELV
1) or protective extra-low voltage (PELV2) with a
nominal voltage, which does not exceed AC 25 V or
DC 60 V. The current source must be located outside
Areas 0 and 1.
Area 0
Area 1
Area 2
3.1. Protection against direct contact (basic protec-
tion)
Protection according to the standard conditions accord-
ing to DIN VDE 0100-410.
Active parts (alternating current voltages of more than
50 V and direct current voltages of more than 120 V) must
be surrounded by wrapping or arranged behind covers
with a protection rating of at least IP2X. Horizontal top
surfaces of covers or wrapping, which are easily acces-
sible, must correspond to at least the protection rating
IP4X. Covers and wrapping must be securely fastened
and have a sufficient resistance and lifespan, in order
to maintain sufficient distance to active parts under the
normally expected conditions of normal operation and
taking the appropriate external influences into account.
Covers may only be removed with tools.
All the products of OBO Bettermann fulfil these require-
ments.

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Mounting and installation information for junction boxes
Areas such as pools of swimming baths and other pools
Area 2
• Accessories, with the exception of sockets;
• Accessories, including sockets, of circuits protected
by low voltages using safety extra-low voltage (SELV¹)
or protective extra-low voltage (PELV²). The current
source must be located outside Areas 0 and 1;
• Shaving socket units according to DIN EN 61558-2-5
(VDE 0570-2-5);
• Accessories, including sockets for signal and commu-
nication technology resources, of circuits protected by
low voltages using safety extra-low voltage (SELV¹) or
protective extra-low voltage (PELV²).
Pools of swimming baths and other pools are divided up
into areas, in which only certain devices may be installed.
Junction/connection sockets may not be erected in Area
0. In Area 1, only junction/connections sockets for cir-
cuits with protection through low voltages with safety
extra-low voltage (SELV¹) are permitted.
The electrical resources must have at least the fol-
lowing protection rating:
• In area 0: IPX7
• In area 1: IPX4
• In area 2: IPX4
This requirement does not apply to shaver socket units
according to DIN EN 61558-2-5 (VDE 0570-2-5), which
are erected in Area 2 and where direct spraying during
showering is unlikely. Electrical resources which are sub-
jected to water jets, e.g. for cleaning purposes in public
baths, must correspond at least to protection rating IPX5
in Areas 1 and 2.
Important protection requirements:
When using safety extra-low voltage (SELV¹), protection
against direct contact must be guaranteed, irrespective
of the nominal voltage level, through:
• Covers or wrapping with a protection rating of at least
IPX2 or IPXXB (protected against finger access) or
• insulation, which can withstand a testing voltage of
500 VAC for at least one minute.
SELV = Safety extra low voltage
PELV = Protective extra low voltage
3.3. Pools of swimming baths or other pools ac-
cording to DIN VDE 0100-702
Outside
the areas
Area 2Area 2
Area 0
Area 1
Edge, walkable Edge, not walkable
1.5 m
1.5 m 1.5 m
2.5 m
2.5 m 2.5 m
2 m 2 m

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Mounting and installation information for junction boxes
Area Outdoors,
for cleaning work with
spray water
Outdoors,
without spray water
Indoors,
for cleaning work with
spray water
Indoors,
without spray water
0 IPX5/IPX8 IPX8 IPX5/IPX8 IPX8
1 IPX5 IPX4 IPX5 IPX4
2 IPX5 IPX4 IPX5 IPX4
Electrical resources used in areas of pools of swimming
baths and other pools must correspond at least to the
following protection ratings:
3.4. Agricultural or horticultural facilities according
to DIN VDE 0100-705
In these areas, there are different requirements for the
switch-off devices of the circuits, but also requirements
for the materials used.
In final circuits with sockets, there must be an offset cur-
rent protection device with a rated differential current =
30 mA.
In all other circuits, except those supplying distributors,
there must be an offset current unit with a rated differen-
tial current = 300 mA.
With regard to the material used for the junction/con-
nection sockets, before the installation it is necessary to
check which chemical concentrations are present in the
environment. This has a serious influence on the resist-
ance of the products used.
Examples:
Stables, chicken coops, pigsties, breeding spaces, stor-
age locations for straw, fertilisers and cereals, etc.
3.5. Damp and wet areas, rooms and outdoor areas
according to DIN VDE 0100-737
Important protection requirements:
In damp and wet areas and rooms, electrical resources
must at least be protected against water droplets (protec-
tion rating IPX1).
In areas and rooms, in which spray water is used and the
resources are normally not sprayed directly for cleaning
purposes, the resources must have at least spray water
protection (protection rating IPX4). In areas and rooms
in which spray water is used, resources that are direct-
ly subjected to the water jet must, with regard to water
protection, have a protection rating suitable to being sub-
jected to a water jet or have sufficient additional protec-
tion that does not impair perfect operation of a resource
protected in such a manner.
Examples:
Canteens, unheated and unventilated cellars, laundries,
refrigerators, greenhouses, laundrettes, etc.
Junction box in greenhouse

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Mounting and installation information for junction boxes
Open-air systems
Important protection requirements:
In protected outdoor areas, resources must at least be
protected against water droplets (protection rating IPX1).
In unprotected outdoor areas, resources must at least be
protected against spray water (protection rating IPX3).
The requirements for protection through an automat-
ic switch-off of the power supply are listed in DIN VDE
0100-470 (VDE 0100-470):1996-02 and, amongst other
things, apply to
• outdoor sockets,
• sockets occasionally used to supply portable
resources outdoors can be expected.
In addition, ventilation and/or drainage is essential!
Examples of unprotected outdoor installations:
Roads, paths and squares, throughways and gardens,
construction locations, platforms, ramps and roofs, con-
struction machines, petrol stations and buildings.
Examples of protected outdoor areas:
Systems on covered platforms, gateways and covered
petrol stations, houses or buildings with a sufficient roof
overhang/with additional weather protection.
3.6. Photovoltaic systems according to DIN VDE
0100-712
Important protection requirements:
The periphery of PV systems is primarily mounted out-
doors. For this reason, there are the following important
protection requirements:
• External influences that are to be expected, such as
wind, ice formation, temperature and sunlight, must
be taken into account.
• In PV systems, it is essential that the heat created by
direct sunlight is dissipated.
All connection/junction boxes must be provided with a
warning that active parts in the boxes could still be ener-
gised after the PV inverter is disconnected.
The requirements for switching off the PV system for
maintenance work can be found in VDE 0100-712, Sec-
tion 53.
In addition, ventilation and/or drainage is essential!
Photovoltaic systemProtected outdoor area

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Mounting and installation information for junction boxes
3.7. Strain relief, cable systems VDE 0100-520
Cable systems must be selected and erected in such
a way that damage is avoided during the erection, op-
eration and maintenance work. The tension on a cable
should not exceed the values stated below. This is de-
pendent on a maximum tensile strength of 1,000 N or a
value agreed with the manufacturer.
• 50 N/mm² for non-flexible cables during routing.
• 15 N/mm² for flexible cables with maintained tensile
loading and non-flexible cables during operation in
permanently installed circuits.
When the above-mentioned values are exceeded, suit-
able measures must be taken. This can be implemented
using a suitable, separated agent/product. This agent
may not damage the cables.
For junction boxes, this specification can take place us-
ing various measures. On the one hand, through the use
of a suitable cable gland, which is directly inserted into
the box, and, on the other, through the use of suitable
strain relief clips, which are mounted outside the box.
Cable glandsStrain relief clips

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Mounting and installation information for junction boxes
4. Junction boxes from OBO Bettermann
The A series family is one of our well-known classic
brands. Made of halogen-free thermoplastic, they of-
fer a simple solution to simple applications. The elastic
material is particularly easy to use and, thanks to the
external fastening and clamshell, the boxes are mount-
ed quickly and simply. The cutting tool supplied in the
packaging also allows proper opening of the pre-marked
cable entries of the required size in the side walls.
The practical sizes in 3 colours are matched to the ap-
plications. The smallest of the family, the A6, is even at
home in inspection lamps and roller blind boxes. Its big
brother can be found in lofts and basements – a real
everyday hero!
4.1. A series – the everyday hero
Areas of application:
• Lofts and cellars in private housing
• Private garages and carports
• Inspection lights and roller blind boxes

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Mounting and installation information for junction boxes
4.2. T series ‒ the all-rounder
If you want a little more, the junction boxes, made from
high-quality materials with sensible wall thicknesses, are
particularly stable and thus perfectly equipped to han-
dle greater loads. Thanks to the UV-stabilised plastic
and the IP66 protection rating, they can also withstand
weathering conditions in indoor areas and, under certain
circumstances, those in outdoor areas as well.
The T series is characterised by its intelligent construc-
tion and practical details, because it is as versatile as
the requirements placed on it. No matter whether deal-
ing with flexible wiring compartments of different shapes
and sizes, the colour differentiation of circuits, checking
of electrical components or use in the maintenance of
electrical function – our all-rounders always have the
right answer. Areas of application:
• Warehouses, sports halls and car parks
• Protected exterior areas, e.g. under roof overhangs
• Escape route lighting for the maintenance of electrical
function

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Mounting and installation information for junction boxes
4.3. X series – the extreme athlete
Professionals are at work here: The junction boxes
are high-quality and robust. With its impact resistance
of IK09, the X series can withstand the strongest me-
chanical loads. Our "extreme athletes" are also dust and
waterproof, as well as UV-resistant. This is why they are
the right choice for challenging industrial applications
and extreme weathering conditions in exterior areas.
The well-thought-out and functional design gives the X
series a particularly high wiring compartment and offers
a wide range of mounting options for installations in any
environment. The wide-ranging and practical equipment
rounds off the range of services, making the X series
ready for all kinds of applications.
Areas of application:
• Industrial applications
• Unprotected exterior areas, e.g. on surveillance cam-
eras
• Greenhouses and workshops

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Mounting and installation information for junction boxes
4.4. Mx series – the robust one
Our aluminium empty housings were designed for use
under the toughest conditions and provide optimum pro-
tection of the installation. The metal housing of the Mx
series withstands extremely high and low temperatures,
as well as large temperature differences. High impact
loads in an industrial surrounding, vandalism or rock
falls are not able to harm the housing. Furthermore, the
Mx series offers perfect EMC protection and is ideally
secured against the entry of dust and water in line with
protection rating IP 66.
Areas of application:
• Mechanical engineering and automation technology
• Industrial, port and ship construction
• Agriculture

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Mounting and installation information for junction boxes

Building Connections
OBO Bettermann Vertrieb Deutschland GmbH & Co. KG
Langer Brauck 25
58640 Iserlohn
GERMANY
Customer Service Germany
Tel.: [phone]
Fax: [phone]
expor[email protected]
www.obo-bettermann.com
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