Mitsubishi Electric s-AIRME-G02 Instructions For Installation, Use And Maintenance Manual page 15

INSTALLATION
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The units can be installed both inside machinery rooms and outdoors.
For indoor installations such as semi-basements, basements or machinery rooms, these must comply with EN 378-3:2021 -
par. 5 requirements (gas detection, ventilation, alarm system, etc.).
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The refrigerant is heavier than air and can stagnate, e.g. below the ground or near the floor, and could reach a flammable
concentration. To avoid ignition, maintain a safe work environment by ensuring appropriate ventilation.
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For R32 units where a release of refrigerant can stagnate e.g. below ground, installation must comply with the requirements
of EN 378-3:2021 on gas detection, ventilation and alarm systems.
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R32 units located outside must be positioned to avoid the refrigerant from flowing into a building or otherwise endangering
people, animals and property, in the event of a leak. Ensure that in the event of leaks no refrigerant penetrates through
vents, doors, hatches or similar. When installing units outdoors with shelter, ensure adequate forced or natural ventilation.
The installation site must meet the requirements of EN 378-3:2021.
In addition to arc, spark, hot surfaces, flames, etc. there are other ignition sources that must be taken into consideration:
o Electric currents and cathodic corrosion protection: take care when the unit is installed near railways, electromagnetic
induction ovens, large welding systems or other apparatus that can induce stray currents in order to avoid source of
ignition.
Stray currents can flow in electrically conductive systems or parts of systems as:
➢
return currents in power generating systems - especially in the vicinity of electric railways and large welding
systems - when, for example, conductive electrical system components such as rails and cable sheathing laid
underground lower the resistance of this return current path;
➢
a result of a short-circuit or of a short-circuit to earth owing to faults in the electrical installations;
➢
result of magnetic induction (e.g. near electrical installations with high currents or radio frequencies).
If parts of a system able to carry stray currents are disconnected, connected or bridged (even in the case of slight potential
differences) an explosive atmosphere can be ignited as a result of electric sparks and/or arcs. Moreover, ignition can
also occur due to the heating up of these current paths.
When impressed current cathodic corrosion protection is used, the above mentioned ignition risks are also possible.
However, if sacrificial anodes are used, ignition risks due to electric sparks are unlikely, unless the anodes are aluminum
or magnesium.
o Generated sparks: due to an imbalance or damage to the bearings, the blades of a fan can crawl or impact against grids
and nozzles; friction or impact or abrasion can lead to overheating or detachment of solid particles at high temperature,
which could represent a potential source of ignition. Make sure that the fans have no abnormal vibrations or noises; in
this case stop the machine and inform the service department.
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The R32 unit is provided with some parts of the refrigerant circuit inside an enclosure: a potentially flammable zone may
extend beyond the boundary of the equipment, especially when doors or panels of the unit are opened following a leak. A
risk assessment shall be conducted to determine the requirements of the location of the unit to be installed.
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The installer shall provide adequately protected documentation that shall be kept near the operating site of the unit and be
clearly readable. It shall, at a minimum, contain details of the flammability of the flammable refrigerant (see EN 378-2,
6.4.3.3).
Installation, use and maintenance manual 15