Siemens Maxum II Manual page 34

Safety Systems - Purging
2.4 Maintenance Considerations for Purged Systems
● The Maxum II Analyzer should be visually inspected at regular intervals to ensure the
integrity of the purge system. The following inspections should be made:
– Instrument air lines and fittings should be inspected for leaks and damage.
– All wiring should enter and leave the enclosure through approved conduit fittings or cable
– All conduit fittings should be inspected to ensure that they are engaged in the threads
– Any unused cable or conduit ports should be sealed closed with approved conduit caps
– All cable should conform to local safety code requirements.
– At startup and whenever maintenance is performed, the electronics enclosure door
– The fast purge relief valve should be visually inspected whenever maintenance is
● It is possible to verify operation of the purging system. When the analyzer is operating
normally verify that the installation area is free of flammable vapors and gases and then
open the electronics door to release purge. For analyzers equipped with an APU, power to
the analyzer should be immediately disconnected by the APU. For analyzers where purge
is monitored by the PECM or PECM-DC, the Purge LED on the front door of the Electronics
Enclosure should blink.
● In systems equipped with an APU, the APU is programmed by the factory with volume
information specific to the Maxum II analyzer. Replacement APUs should be ordered only
though Siemens. The APU should not be reprogrammed except by authorized personnel.
● For certified cable glands, care should be taken to comply with any special conditions for
safe use listed in the cable gland certificate.
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glands and should be inspected for wear, cracks, or leaks.
correctly and are tightened down to necessary tightness.
or seals.
gaskets should be inspected for wear or damage.
performed to ensure that it is free of obstructions or damage.
Explosion Protection Safety Standards
Manual, August 2017, A5E02220442001 Rev 8