The document discusses requirements for operating electrical switching devices outdoors, including: - Weather and environmental influences require protection of switching devices through enclosures rated to a minimum IP protection class. - Enclosures must protect against ingress of dust, water, and foreign objects depending on the pollution degree specified by the manufacturer. - Additional measures like heating may be needed to prevent condensation or temperatures below the device limits. - Ventilation could also be required for devices that generate significant heat. - The document provides guidelines for selecting properly rated enclosures and accessories to safely operate switching devices in outdoor installations.

1. Felix G. Hensel
Managing partner of
Gustav Hensel GmbH & Co. KG
Collection
of
new
ideas
in
the
Electrotechnical
Industry
The ELEKTRO
Customer Information for Electro-technical Specialists
Dear Reader,
our years of experience related to
electrical installation and distributi-
on systems in demanding environ-
ments provide us and our clients
always a great challenge.
This depends certainly on the fact
that you automatically assume that
Hensel products prove themselves
in difficult environmental conditions
and the installed devices will work
without difficulties - not only indoors
but also in outdoor installations. This
confidence honors us and encoura-
ges us to look for better and safer
solutions!
This includes not only an excellent
enclosure quality, but also the ne-
cessary system accessories that are
essential for long-lasting operating
functions. This is supported by an
intelligent selection table for rapid
decision making.
We look forward to a fruitful and a
challenging cooperation with you.
Sincerely
1/2013
How must an enclosure be constructed for the
operation of electrical devices in outdoor installations?
enclosure.
For a continuous and troublefree
operation the special climatic in-
fluences and effects on the equip-
ment are to be considered in addi-
tion to the requirements for indoor
installations.
No electrical equipment and
switching device can be used out-
doors without protection. Enclo-
sures protect electrical equipment
against external influences. There-
by the installed device determines
the minimum requirements for the
Are super-tight enclosures
safe to operate outdoors?
Operation of switching devices in outdoor
installations
Why doesn‘t the system
operate? The distributor
has already got
IP 65!

2. Operation of switching devices in outdoor installations:
What outdoor influences cause any effect and what
requirements are to be considered?
Weather-related
or
ambient influences
Characteristic feature
of the switching device,
for example miniature circuit breaker
Minimum requirements
for enclosure
here: to protect the MCB against
external influences
Dust Pollution degree 2
„It occurs only non-conductive polluti-
on. However a temporary conductivity
caused by condensation must be
expected.“
Protection of the housing must be so
high that the permissible pollution of
the switching device is not exceeded;
here: at least IP 5X
foreign bodies (f.example insects)
IP 2X
protection against ingress of solid
foreign objects
≥ 12.5 mm Ø
≥ IP 4X
Protection against ingress of solid
foreign objects ≥ 1 mm Ø
(Minimum requirements of DIN VDE 0100 Part 737)
Water: Rain/snow
IP X0
no protection
≥ IP X3
Protection against ingress of water
(Min. requirements of DIN VDE 0100 Part 737)
suitable for harsh environment and/or
outdoor installation
(Follow manufacturer‘s instructions)
Sun: UV radiation
No specification,
as devices are not tested
for UV resistance
UV resistant material
(Follow manufacturer‘s instructions)
Sun: Heat
max. 55° C
ambient temperature
at switching device
Any heat that is generated needs
to be effectively dissipated,
ventilate housing, if necessary,
or choose larger housing
Frost/cold
max. -5° C
ambient temperature
at switching device
Cold-resistant material,
housing may be heated
Humidity (condensation)
93 % at 40 °C
20 % at 55 °C
according to DIN 40046
Reduce condensation,
ventilation by pressure compensation
or heating
Weather and environmental influences determine the selection of an enclosure,
regarding the switching devices to be installed!
Switching devices, this includes for exam-
ple switches, terminals, fuses and trans-
formers, are generally not suitable for un-
protected outdoor installation. Their rating
is dependent on the ambient conditions.
Possible contamination, combined with
moisture, reduce the electrical insulation
properties of the devices.
Weather and environmental influences,
therefore, require the protection of switch-
ing devices by a housing.
Basically, the general requirements apply
as for indoor installations, for example as
the protection against electric shock is re-
garded.
When installed outdoors, however, ad-
ditional requirements must be observed.

3. Enclosures properly selected for operat-
ing switching devices outdoors:
Conclusion:
The safe operation of a switching device in outdoor installations requires enclosure systems
and system accessories for additional measures in order to counteract effects of the weather.
Not only the immediate vicinity of a
switching device, the installation also de-
termines the amount of pollution such as
conductive dust and humidity and thus
influences the creepage distances.
Under the influence of moisture, contami-
nation is conductive.
Pollution caused by water deposits,
soot, metal or coal dust is always con-
ductive.
The pollution of the switching device
can be reduced , by the use of housings
(enclosures), encapsulation or hermetic
seals.
This protection may be ineffective if the
equipment is exposed to condensation
or if it produces the pollution itself under
normal operating conditions.
Pollution degree 2
(specified by the manufacturer)
”It only occurs non-conductive pollution.
Sometimes a temporary conductivity caused by
condensation must however be expected“
DIN VDE 0110-1
Additional
measures for heat
dissipation are
NOT required
> 55°C
Ambient tem-
perature at
the switching
device
Choose larger
enclosure for
improved heat
dissipation
No venting to
prevent illegal re-
duction of degree
of protection.
NO
NO NO
Required protection provided by enclosures for compliance
with the degree of pollution:
≥ IP 5X protection against the ingress of foreign bodies (dust) and
≥ IP X3
protection against ingress of water with harmful effects
(Minimum requirements of DIN VDE 0100 Part 737)
Enclosure at least degree of protection IP 53
≥ IP 53
+ heating
—
≥ IP 53
—
—
Changes
in temperature
or high power
dissi­pa-
tion?
-5°C
Ambient tem-
perature at
the switching
device
additional
heating
Pollution degree 3
(specified by the manufacturer)
”Conductive pollution occurs or dry non-conduc-
tive pollution which becomes conductive due to
expected condensation.“
DIN VDE 0110-1
55°C
Ambient tem-
perature at
the switching
device
Additional
measures for heat
dissipation are
NOT required
NO YES
NO
YES
ventilation for
better heat
dissipation
additional
heating
YES
NO
NO
Required protection provided by enclosures to comply with the pollution
degree according to DIN VDE 0100-737 at least:
≥ IP 4X
protection against solid bodies larger than 1mm and
≥ IP X3
protection against ingress of water with harmful effects
(Minimum requirements of DIN VDE 0100 Part 737)
Enclosure at least degree of protection IP 43
IP 43
+ heating
—
IP 43
—
—
IP 43
+ heating
+ ventilation /
pressure com-
pensation
IP 43
—
+ ventilation /
pressure com-
pensation
additional
heating
-5°C
Ambient tem-
perature at
the switching
device
Changes
in temperature
or high power
dissi­pa-
tion?
-5°C
Ambient tem-
perature at
the switching
device
YES
YES
YES
YES
Switching devices
Pollution de-
gree specified
by the manu-
facturer

4. Delivery in India via Hensel authorized
distributor network ­
spanning 130 cities and industrial centers.
Delivery in South East Asia via Hensel authorized distributor
­
network in all ASEAN countries.
Distribution boards
Combinable enclosure system
with door up to 250 A, IP 65
DK Cable junction boxes
1.5 to 240 mm
2
, IP 54-67
KV Small-type distribution
boards up to 63 A,
3 to 54 modules, IP 54- 65
Mi Distribution boards
up to 630 A, IP 54-65
Cable entry systems
Photovoltaik distributors
that meet the standards
Construction board panels
up to 630 A, IP 44-65
R. Rajesh
Managing Director
Hensel Electric India
Pvt Ltd
info@hensel-electric.in
www.hensel.in
Sunguvachathram
-
Walajabad
Road
4th
km
behind
Samsung/Flextronics
Sriperumbudur
-
631
604
∙
Kanchipuram
Dist,
Tamil
Nadu
Phone:
+91-44-3727
0202
Fax:
+91-44-3727
0200
Email:
info@hensel-electric.in
∙
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Industrial
Electric
Power
Distribution
Systems
35
Kunnam
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Product information
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Ventilation
Ventilation flange Mi BF 43
for ventilation of Mi distribution boards in the event of
extremely high internal temperatures or a risk of water
condensation
Degree of protection IP 43
Pressure compensation
Combi climate glands KBM .. / KBS ..
reduce condensation that may form through rapid
temperature changes or intense sun exposure
Degree of protection IP 66 / IP 67
Heating
Cabinet heater
for distributors in unheated rooms or outdoors. It should pre-
vent the formation of condensation. In outdoor installations
also an excessive drop of the interior temperature can be
prevented.
Protection
Canopy Mi DB ..
offers protection against rain, snow and ice
and dust
Mi Power Distribution boards up to 630 A

Combinable enclosure system, insulation-enclosed,
total insulated, degree of protection IP 65,
for the assembly of power switchgear and controlgear
assemblies (PSC) up to 630 A
in accordance with IEC 61 439 Part 2

Material durability for outdoor installation:
temperature resistant -40° C up to + 120° C,
UV resistant

Impact resistant IK 08, flame retardant
1
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Grid, on-grid and
off-grid systems
Product information as at: 10/2011
Gustav Hensel GmbH Co. KG
Industrial Electrical Power Distribution Systems
Altenhundem
Gustav-Hensel-Straße 6
D-57368 Lennestadt, Germany
P.O. Box 1461
D-57344 Lennestadt, Germany
Phone:+49 (0)2723/609-0
Fax: +49 (0)2723/60052
E-Mail: info@hensel-electric.de
www.hensel-electric.de
The solution for reliability: Mi-distributors
with system accessories permanently
protect electrical equipment outdoors.