Siemens SIMOTICS XP 1MB155, Operating Instructions Manual

Page: 22 / 152

Description
3.1 Area of application
1MB155 / 1MB555
20
Operating Instructions, 03/2018, A5E41926185A
DANGER
Explosion hazard from hybrid mixtures
Hybrid mixtures are mixtures of flammable dusts with explosive gas/air atmospheres which
can together create a dangerous explosive atmosphere if they occur at the same time.
Changes can arise in the safety characteristics here, such as a change in the zonal
classification, increase in the explosion pressure, reduction in the minimum ignition energy
and a reduction in the maximum temperatures to be observed.
An explosion can result. This can result in death, serious injury or material damage.
• For this reason, the relative characteristics must be considered both for gas (zones 0, 1
and 2) and for dust (zones 20, 21 and 22) where hybrid mixtures arise. It is necessary
for a competent assessor to determine in the individual case whether the parameters
determining ignition are unfavorably affected in a particular hybrid mixture.
•
Motors with dual plates for G (“Gas”) and D (“Dust”) may only be used where these two
occur after prior examination of the properties of the hybrid mixtures by the user.
Type of protection Ex db
The machine including the terminal box has type of protection "flameproof enclosure" Ex db
in accordance with IEC / EN 60079-0 and IEC / EN 60079-1 and is designed for operation in
Zone 1 or Zone 2 in accordance with IEC / EN 60079-10-1.
Type of protection Ex db eb
The machine without the terminal box has type of protection "flameproof enclosure" Ex db in
accordance with IEC / EN 60079-0 and IEC / EN 60079-1. The terminal box has type of
protection "increased safety" Ex eb in accordance with IEC / EN 60079-0 and IEC / EN
60079-7. The machine and the terminal box are intended for use in Zone 1 or Zone 2 in
accordance with IEC / EN 60079-10-1.
Type of protection Ex tb, Ex tc
Optionally, this motor has "Protection through enclosure" (Ex t) type of protection according
to IEC / EN 60079-0 and IEC / EN 60079-31 . Then, it may be operated in hazardous areas
of Zones 21 and 22 in the Ex tb type of protection and Zone 22 in the Ex tc type of protection
according to IEC / EN 60079-10-2.