Exhaust Diffuser - Siemens Maxum II Manual

Safety Systems - Purging
2.3 Electronics Purging System (with Automatic Purge Unit)
Figure 2-15
The maintenance switch for the MMO configuration is on the top left of the regulator panel, to
the right of the electronics enclosure.
Figure 2-16
2.3.6

Exhaust Diffuser

In a properly purged system, all holes including all tubing and wiring entry points are normally
sealed closed with metal fittings or silicone sealants. The electronics enclosure door is also
normally closed and it is sealed with gaskets. The primary exit path for excess pressure is
through the APU to the exhaust diffuser on top of the analyzer. It is designed with downward-
facing holes to prevent dust and other foreign material from accumlulating in the APU exit port.
Near the exhaust diffuser is a hollow retaining screw that stabilizes the APU and functions as
a vent for the atmospheric reference in the APU.
30
Location and Close-Up of Maintenance Switch (MAA, Set for Normal Operation)
MMO APU Maintenance Switch
Explosion Protection Safety Standards
Manual, August 2017, A5E02220442001 Rev 8