Description Of P&T Expt - Videotec EXPT Série Manuel D'instructions

4 Description of P&T EXPT
The explosion-proof pan & tilt units EXPT series have been designed for movement (both on horizontal and
vertical planes) with cameras working in industrial areas with explosive environments like gas, vapours, fogs or
mixed air and powders.
The pan & tilt units EXPT, supplied with camera housing, 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 unit essentially consists of a base body, a central body and a third body which is used as camera housing.
The base body is a tunnel for connecting the control cable (multicore cable with 29 conductors and two coax),
while the central body includes the electric motors for both pan & tilt movements. The third body, as already
mentioned above, acts instead as housing for camera and its operation accessories.
The central body, cylindrical tube-shaped, contains two potentiometers for setting the automatic cyclic
movement and the electronic board for the automatic movement, furthermore contains the connections for the
control cable and one GAS 3/4" cable gland.
The central body is composed of the electric motors for horizontal and vertical movements. The pan & tilt units
EXPT series are equipped with single-phase electric motors (uniform speeds); the electric motors transmit the
pan & tilt movements through a wheel-pinion and link chain system, allowing each movement in both directions
with instantaneous stopping and rotation inversion. The internal motion mechanism is based on the endless
screw-gear rim system, so as to eliminate the possibility of noisy clearances during operation.
Also 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 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 P&T model is built according the 94/9/CE Atex standard.
The unit can be also supplied with the following additional accessories:
• mounting bracket (EXPTWB) for wall installation;
• sunshield for housing
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