Videotec IRMEL EXPT Mode D'emploi page 9

GENERAL DESCRIPTION.
The explosion proof pan & tilt units EXPT series have been designed for movement (both on horizontal
and vertical planes) of videocameras and other equipments and fittings working in heavy duty and explosive
environment.
The EXPT pan & tilt units, supplied with videocamera housing, are made with strong anticorodal
aluminium die-cast alloy (RAL 7032), stove enamelled, and they are manufactured in explosion proof
execution EExd IIB T6 and EExd IIC T6 according to CENELEC standards, for installation in explosive
atmosphere.
The unit essentially consists of a base body, a central body and a third body which is used as
videocamera housing. The base body is a tunnel for connecting the control cable (multiconductor cable: 29
wires, 2 coax cable, 7,5 meters length), 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 videocamera and its
operation accessories.
The base body, cylindrical tube-shaped, contains the connections for the control cable and two
potentiometers for setting the automatic cyclic movement of the horizontal rotation (optionals) 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 videocamera 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 videocamera fixing board.
The unit can be also supplied with the following additional accessories:
- mounting bracket (PTBEX) for wall installation;
- thermostatically controlled heater 24Vac, 8W (EXPT/HC)
OPERATION MODE.
The pan & tilt unit can be remotely controlled according to the following operation modes:
- "MANUAL", directly driving the electric motors through a control console, with istantaneous starting,
stopping and rotation inversion both on horizontal (max 360°) and vertical (max -90° ÷ +90°) planes; two
mechanical obstructions are installed beyond the maximum allowed ranges, so as to avoid further
rotations in case of bad workings of the electric limit stops (microswitches).
- "AUTOMATIC CYCLIC", only for the rotation on the horizontal plane, in both directions within a
maximum angle of 270°, according to the limits fixed setting the two potentiometers (RV1 and RV2)
installed in the printed circuit board of the base body (autopan option).
- "AUTOMATIC ON PRESET VALUES", through suitable decoder provided with preset function (not
included in the supply) and two potentiometers (P1 and P2) located on the rotation axes and
mechanically linked to the horizontal and vertical movements (preset option).