SICK DUSTHUNTER SP100 Ex-2K, Руководство по эксплуатации, Страница: 23 / 130

23 8024493/AE00/V1-0/2020-09| SICK O P E R A T I N G I N S T R U C T I O N S | DUSTHUNTER SP100 Ex-2K
Subject to change without notice
PRODUCT DESCRIPTION
3
3.3.2 Protection concept
Sender/receiver unit protection concept
The mechanical construction of the DUSTHUNTER SP100 Ex-2K is intended for use in
explosive atmospheres of category 2G and 2D. The enclosure is dust-tight and the surface
temperature limited. Thus the device corresponds to ignition protection type “t” (protection
by enclosure). For this purpose, ignition protection type “d” (flameproof enclosure) is used,
in which ignitable components are installed in an enclosure that can safely withstand the
pressure of an explosion inside the enclosure. In the enclosure structure, the technologi-
cally required joints have also been designed so long and narrow that escaping hot gases
lose their ignitability outside the enclosure. This means that the joint is flameproof and
prevents the transmission of the explosion to the surrounding atmosphere. The device uses
a laser to perform its measuring task. To avoid ignition of a potentially explosive
atmosphere by optical radiation, the laser module meets the criteria of the type of
protection inherently safe optical radiation “op is” according to EN60079-28. An
inadmissible heating of the enclosure surface above the specified temperature class is also
ruled out in the event of a fault by internal temperature fuses.
Thermal cutout
Thermal cutout mechanisms are built into the DUSTHUNTER SP100 Ex-2K sender/receiver
unit. Further operation is prevented when the ambient temperature rises above or falls
below the specified ambient temperature limits (
see “Technical data”, page 118 ). Send the
device back for a factory inspection when one of the two temperature limits has been
exceeded (
see “Return delivery”, page 117 ).
Control unit protection concept
The MCUDH Ex-3K control unit is intended for use in explosive atmospheres of category 3G
and 3D. Ignition protection types “ec” (increased safety) and “t” (protection by enclosure)
are used. In addition, ignition protection types “nA” and “nC” are used on the versions with
integrated power supply unit.
Take into consideration that the thermal cutout mechanisms refer to the permissible
ambient temperature, not to the maximum surface temperature with regard to explosion
protection, which is higher in this case.