Installation and operation manual
12/20 0013321 en 2023.05
Service of the plant and enclosure
4.2 Area classification
All refrigerant-containing parts are located in a ventilated enclosure or open air. The ventilated
enclosure is classified as a machinery room, and the requirements for a class III location are
applied (EN 378).
As a unit, the enclosure is intended for use in normal areas; however, the inside of the venti-
lated enclosure and a volume around the ventilation outlet opening are zone 2 areas during
normal operation.
Under ATEX, areas are classified according to the hazards associated with flammable gas.
The following classification applies to the inside of the refrigerated and ventilated enclosure:
•Zone 2: an area in which a flammable gas atmosphere is not likely to occur during nor-
mal operation, and if it does occur, it will exist for a short period of time only.
•Secondary grade of release: this is not expected to occur during normal operation,
and if it does occur, it will be infrequent and for short periods of time only.
A refrigerant detector and ventilation are suitable equipment for zone 2: a refrigerant detector
fitted into the enclosed space to start forced ventilation, if necessary, and to isolate all electrical
ignition sources that are not suitable for zone 2 as ultimate protection (EN 60079-10).
The local fire authorities may have certain additional requirements for the location of the plant.
Such requirements may include:
• Distance to buildings and other machinery
• ATEX according to EN 60079-10 and EN 378-3
The unit fully complies with the requirements of both EN 60079-10 and EN 378-3.
Fig. 14
Note: When installing a unit, it must be taken into consideration that the emergency ventilation
exhaust outlet is zone 2 (EN 60079-10).
When installing equipment within 2 metres in all directions from the ventilation outlet, as illus-
trated in Fig. 14, all ignition sources must either be suitable equipment for zone 2 or electrically
isolated when the leak detection system in the enclosure detects high level alarm. This area
must be marked with the signs “No open flame”, “Flammable gas” and “The unit is filled with re-
frigerant R717”.
Safety valve outlet
Ventilation outlet
Zone 2
2 m
2 m
2 m