Table of Contents
Advertisement
8. Explosion Protection
In order to prevent an explosion, a detonation or a fire,
potentially explosive atmospheres should be avoided
wherever possible!
As a rule, a potentially explosive atmosphere must be
divided into respective categories (zones) in accordance
with applicable regulations, whereby a differentiation is
made between atmospheres, which lie inside or outside
the airstream.
Equipment with special explosion protection must be
deployed only in their declared category!
8.1 Service, maintenance and repair
• Service, maintenance and repair may be carried out
only by respectively trained personnel!
• Work tasks may be carried out, either in a non-poten-
tially explosive atmosphere only, or with an avoid-
ance of ignition sources. For this, it must be especially
regarded, that all work materials deployed are author-
ised for the respective zone
• Prior to opening the equipment, the system must be
mechanically and electrically taken out of service and
secured accordingly.
• In addition, it may be required to purge the equipment
with fresh air, as necessary, in order to remove or dilute
a potentially explosive atmosphere. In particular, this
is required when the internal gas groups differ from
the external gas groups! This task can be automated
through the control system.
• In particular, the atmospheric concentrations can
change in the event of a system shutdown, increas-
ing the risk of an explosion! In any case, all types and
sources of ignition should be avoided when performing
service, maintenance and repairs.
8.2 Identification marking
Identification as to the type of atmosphere, in which the
equipment can be deployed, is located at the ventilator
chamber. For this, the identification between internal
(conveyed atmosphere) and external (installation room)
will differ - the equipment may deployed only in agree-
ment with the respective equipment identification.
A warning notice is located on the equipment, which
must not be removed:
This equipment can convey a potentially explosive
atmosphere!
May be opened only by specialist personnel with
suitable work materials!
As an individual module, the RAC equipment, alone,
cannot guarantee a complete and all-encompassing pro-
tection against explosion, as the protection concept must
apply to the complete system.
The overall responsibility for explosion protection lies ulti-
mately with the operator or the system manufacturer.
26
www.swegon.com
8.3 Avoidance of ignition sources
Fan
In a potentially explosive atmosphere, the fan may be
operated only with the respective identification mark-
ing and authorisation for the deployment zone. For this,
mechanically generated sparks, such as scraping of the fan
wheel with the inlet nozzle, must be avoided. This must
be ensured through appropriate material combination
and through a careful adjustment of the die gap. Further-
more, the maximum allowable fan turning speed may not
be exceeded, as otherwise parts from the fan wheel can
loosen and possibly cause mechanical induced sparks!
Under no circumstances should the fan wheel
scrape against the inlet nozzle! This can cause igni-
tion sparking.
The fan is to be continually monitored for vibrations. The
can be achieved by an explosion protection designed
vibration monitor, as appropriate, or through a daily visual
check process. If vibrations are optically or acoustically per-
ceivable, the equipment must be immediately taken out of
service and be repaired.
Electrical components
All electrical components (e.g. electrical motors, lamps,
switches, etc.) must possess with the respective identi-
fication marking and be authorised for the deployment
category in order to be operated in a potentially explosive
atmosphere.
Wiring must be carried out in accordance with the appli-
cable standards. Overall, a proper potential equalisation
must be warranted throughout the entire system so that
static electricity can be eliminated as a source of potential
ignition sparking.
As a rule, the frequency converter is not suitable for
deployment in a potentially explosive atmosphere. It will
be delivered as a loose component only and must not be
deployed in a potentially explosive atmosphere.
Lightening protection
Roof control centres with Explosion protection, in particu-
lar, require the installation of proper lightening protection!
Hot surfaces
Depending upon the atmosphere, it must be noted that
pipelines (e.g. for heaters) temperatures can reach up to
110°C. These temperatures can be sufficient to be an igni-
tion source.
The company reserves the right to make design changes without prior notice.
EN.SILVER.110322
Advertisement
Table of Contents
