thuba PS 830, Manual

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Manual BVS 19 ATEX E 080 X 17
Edition March 2020 thuba Ltd., CH-4002 Basel
Copyright Switzerland
3 Introduction: simplified pressurized
enclosure system
The use of simplified pressurized enclosures
allows the operation of ‘non explosion protected’
devices in hazardous areas inside zone 2. The
protection type ‘pressurization’ is based on the
principle of maintaining a constant pressure
using air or a protective gas to prevent an explo-
sive mixture forming near the apparatus inside
the pressurized enclosure.
Generally, before start-up, the pressurized enclo-
sure must be purged with air or protective gas to
remove any explosive mixture that may be inside
the enclosure. This automatic procedure is called
purging process.
A simplified pressurized enclosure system con-
sists of two components and the enclosure.
1. Control unit PS 830 for process control and
monitoring
2. Solenoid valve SVD.L.x or a sinter metal
throttle SD840 to control air input fed by
pressured air network
3.1 Pressurized enclosure system PS 830
The device PS 830 is the control device of a PS
830 pressurized enclosure system.
The control device PS 830 provides all neces-
sary functions to install a pressurized enclosure
system according IEC 60079-14 section 13, and
IEC 60079-2 „pzc“. The PS 830 measures the
internal pressure and alarms or powers off, if the
pre-defined minimum pressure is reached. The
PS 830 can also pre purge the housing before
automatic powering on the housing. In this case
connect a digital working 2/2 way solenoid valve
to the appropriate terminals. The solenoid must
have a separate certification for zone 2.