Siemens SIMOTICS XP 1MB5 Series Operating Instructions Manual page 99

tests are carried out. We recommend that these tests be carried out and documented in
coordination with the responsible authorities.
System-specific ignition hazards
The criteria for the respective zonal classification are not harmonized and the assessment of
the operational risks, the local operating conditions and the various monitoring methods are not
standard. As a consequence, the remedial measures recommended by the supervisory
authorities may also differ depending on the authority's area of responsibility. The machine
manufacturer cannot provide general recommendations in this regard.
Note
Binding clarification of the local risks and of any required measures can only be provided by the
company operating the plant or system in agreement with the supervisory authority
responsible. The risk assessments from IEC / EN 60079-15 or -7 can be used to assess system-
specific ignition hazards.
Explosion hazard if the temperature class is exceeded
If a force-ventilated machine is operated without a separately driven fan, the temperature class
or the maximum surface temperature of the machine can be exceeded.
In an explosive atmosphere, there is a risk of an explosion. This can result in death, serious
injury or material damage.
● Install an interlock circuit that prevents the machine from being switched on if the separately
driven fan is not switched on/is not operational.
● Do not commission the machine without a separately driven fan.
Explosion hazard due to overheating of the machine caused by a layer of dust
Layers of dust thicker than 5 mm can lead to overheating of the machine due to their heat
insulating effect. The maximum surface temperature of the machine cannot be adhered to. The
dust can ignite, resulting in an explosion. This can result in death, serious injury or material
damage.
● Dust the machine regularly.
● Do not allow dust layers thicker than 5 mm to build up on the machine surface.
● Do not switch the machine on until the dust has been removed.
1MB5 SH 400/450
Operating Instructions, 05/2019, A5E45959221A
8.1 Safety instructions for operation
Operation
97