Description Of Housing Exh; Glass Protection Device; Application Field - VIDEOTECH EXH Manuel D'instructions

4 Description of housing EXH

The explosion proof housing EXH series have been designed to be used with cameras working in industrial
areas with explosive environments like gas, vapours, fogs or mixed air and powders.
The EXH housings, are made with strong Anticorodal aluminium die-cast alloy of AlSi7Mg EN AC-42000 group
and their chemical composition is defined in the UNI EN 1706 standard.
Depending on the model, all external components are stove enamelled using powder or treated with special
coatings offering an excellent resistance to UV rays, salt-spray, environment polluting substances.
They are constructed according to the 94/9/CE ATEX standard and IEC 60079-0:2000, IEC 60079-0:2001, IEC
61241-1:2004 protocols.
The camera housing consists of a cylindrical tube, fitted with a flange which incorporates a rugged and
transparent glass; on the opposite side it is installed an other flange for closing the tube and supporting the
camera fixing board. The weatherproof standard IP65 is ensured also by two 3/4" cable glands for service
cables of a diameter ranging from 14 mm to 17 mm.
The thermal imaging camera housings, detecting the heat emission, require a special filter on the front part of
the housing. Its structure, mainly composed by Germanium, guarantees the same resistance and security
features as well as the standard glass.
This housing model is built according the 94/9/CE Atex standard.
The unit can be also supplied with the following additional accessories:
• sunshield (EXHS);
• mounting bracket with articulation support (EXWBJ) for wall installation;

4.1 Glass protection device

The housing series EXH can be equipped with the glass protection device, installed on the front opening of the
camera housing. It consists of a connection flange with the housing, a closing flange and an explosion-proof
central body containing a rugged and transparent glass, a direct current motor power supplied at 24 Vdc, two
windings and a transparent Mylar film, installed just in front of the glass. The motor drives, through four pinions
with gear rim, the winding for recovering the dirty Mylar film, while at the same time the other winding installed
on the opposite side releases the clean film. The motor is remotely controlled through a two wires on-off contact
(common and + 24Vdc).
The control unit of the glass protection device is provided by the customer!
The transparent Mylar film allows to obtain about 350 shifting steps. When the film is dirty, the operator will
activate the motor shifting the film until to obtain a clean camera picture (the step for allowing the completely
shift of the dirty film is about 50 cm). The end of the Mylar film will directly indicated to the operator, through
suitable marks printed on the last 50 cm of the film.
If requested, the film shifting could be also automatically time-controlled, through a suitable control system (not
included in the supply).
To replace the Mylar film, take out the windings and replace the dirty film with a clean one.

4.2 Application field

The use of housing EXH is in fixed position for the vigilance, by camera installed by the user inside, of
zones with atmosphere explosive classified 1-21 or 2-22.
• The EXH housing s constructed and certificated in compliance to the 94/9/CE ATEX standard and the IEC
60079-0:2000, IEC 60079-0:2001, IEC 61241-1:2004 protocols which define the range of application and the
minimum safety requirements.
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