HYDAC ELECTRONIC HFS 2500, Руководство по эксплуатации, Страница: 27 / 40

Flow switch HFS 2500 with ATEX approval Page 7
Status 2020/05/19 HYDAC ELECTRONIC GMBH Mat. No.: 669884
The circuit must not incorporate any effective inductivities or effective capacities. For contact
protection a fuse with the nominal value of
1 A für Change-over contact SEM-A
2 A für Normally open contact SEM-E
must be provided outside of the Hazardous Area for the circuit, unless the switch unit is connected
to an intrinsic safe circuit.
The switch unit may be used in potentially explosive atmospheres classified as Category 2
Safety recommendation:
The explosion proof safety can be increased when the switch unit is connected to an intrinsically
safe circuit e. g. using a galvanic isolator with an intrinsically safe input circuit. The galvanic isolator
must be mounted in the safe area.
4.4.3 Specific conditions of use
1. Each switch unit must be connected via a fuse according to IEC 60127-2-1 which is related
to its rated current as short circuit protection. Alternatively a motor-circuit switch with short
circuit and thermic quick release can be used. The fuse must be located inside of the
supply unit or must be installed separately in front of the switch contact. The safety rated
voltage must be equal of higher as the maximum value of the nominal voltage of the
contact. The breaking capability of the fuse must be equal or higher as the maximum
expected short circuit current at the installation location (typ. 1500 A).
2. The switch units are only for the use in mounting rails.
3. The circuit must not incorporate any effective inductivities or effective capacities.
4. Der switch unit can be connected to an intrinsically safe circuit; in this case the fuse is not
anymore needed.
5. The connection cable is to be installed to a housing which covers the demands of a suitable
ignition protection type according to EN 60079-0, if the connection is done in potentially
explosive atmospheres.