Bartec APEX (APC) 07-3704 Series, Operating Instructions Manual

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APEX / SILAS
Pressurized Cabinet
Operation
Rev. - 01-3704_7D0001_Manual_APC-SPC_20200617_jrs_en.docx Page 31 of 40
Purging phase
The pressurized enclosure of the APEX (SILAS) pressurized cabinet is purged
with purging gas in order to remove any explosive gas-and-air mixture inside or
to dilute it to a harmless concentration before the possible sources of ignition
are connected and activated in the pressurized enclosure.
This process prepares the pressurized enclosure for the operating phase. The
necessary purging volume depends on the free capacity of the pressurized
enclosure.
Purging phase sequence:

Increase in the flow with purging gas.

The set purging time counts down and the APEX (SILAS) pressurized
cabinet is purged with purging gas.

At the end of the purging time, the purging gas valve closes.

The next phase, the “operating phase“ is initiated.
This phase is not applicable for dust applications because it is replaced by the
prior cleaning of the switch cabinet from dust.
Operating phase
The operating phase begins when the purging gas valve closes.
The operating pressure must be maintained throughout the entire operation of
the pressurized enclosure to prevent the penetration of combustible
substances. The electrical installed parts in the pressurized enclosure are
connected and activated by means of the Ex p control unit.
If the enclosure pressure drops below the set minimum levels during the
operating phase, all electrical installed parts in the pressurized enclosure
which are not themselves explosion-proof, are switched off and the purging
process starts again.
In the case of the “pyb“ and “pzc“ types with manual switching on and off, the
deactivation must be performed manually. The message is given via a visual
and/or audible signal.
Operating phase sequence:

The purging value closes and the leakage losses are compensated.

The Ex p control unit activates the pressurized enclosure of the APEX
(SILAS) pressurized cabinet.