Distillation Process Analyzer DPA-4.5
Design and function
4.7 Operating elements
Figure 4.10: Control box key switch
To prevent potentially explosive atmospheres from developing,
overpressure is created with the aid of instrument air in the interior
of the control box.
The overpressure is monitored by a pressure monitor. For
servicing and maintenance work, monitoring can be switched off
using the
key switch
on the front side of the control box.
WARNING
Explosion protection is no longer provided
when the pressure monitor is switched off
The control box contains ignition sources.
Operating the device when the pressure monitor of
the control box is deactivated can result in
explosions in potentially explosive atmospheres.
For this reason:
– Never deactivate the explosion protection during
normal operation. Leave the key switch in the
Explosion protection On
position.
– Deactivation of the explosion protection
(
Explosion protection Off
position) is solely
intended for service work. No potentially
explosive atmosphere may be present during this
time.
– After performing service work, close the control
box carefully with the aid of the two catches and
switch on the pressure monitor again using the
key switch.
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