21
b.
Specialist’s Manual
a.
Aptitude requirement for maintenance
man(repairs should be done only be
specialists).
Safety preparation work
11
15
4
Room area (m
2
)
<0.152
0.225
0.304
Maximum charge (kg)
Work procedure
General work area
table a - Maximum charge (kg)
The maximum refrigerant charge amount is shown
on the following table a.
(Note:Please refer to the nameplate for the charging
quantity of R290).
Any person who is involved with working on or
breaking into a refrigerant circuit should hold a
current valid certificate from an industry-accredited
assessment authority,which authorises their co-
mpetence to handle refrigerants safely in acco-
rdance with an industry recognised assessment
specification.
Servicing shall only be performed as recomme-
nded by the equipment manufacturer. Mainten-
ance and repair requiring the assistance of other
skilled personnel shall be carried out under the
supervision of the person competent in the use
of flammable refrigerants.
Prior to beginning work on systems containing fla-
mmable refrigerants, safety checks are necessary
to ensure that the risk of ignition is minimised. For
repair to the refrigerating system, the following pr-
ecautions shall be complied with prior to conducting
work on the system.
Work shall be undertaken under a controlled pr-
ocedure so as to minimise the risk of a flammable
gas or vapour being present while the work is being
performed.
All maintenance staff and others working in the
local area shall be instructed on the nature of work
being carried out. Work in confined spaces shall be
avoided. The area around the workspace shall be
sectioned off. Ensure that the conditions within the
area have been made safe by control of flammable
material
Checking for presence of refrigerant
The area shall be checked with an appropriate re-
frigerant detector prior to and during work, to ensure
the technician is aware of potentially toxic or flamm-
able atmospheres. Ensure that the leak detection
equipment being used is suitable for use with all ap-
plicable refrigerants, i.e. non-sparking, adequately
sealed or intrinsically safe.
Presence of fire extinguisher
No ignition sources
If any hot work is to be conducted on the refrige-
ration equipment or any associated parts, approp-
riate fire extinguishing equipment shall be available
to hand. Have a dry powder or CO
2
fire extinguisher
adjacent to the charging area.
No person carrying out work in relation to a refrig-
eration system which involves exposing any pipe
work shall use any sources of ignition in such a ma-
nner that it may lead to the risk of fire or explosion.
All possible ignition sources, including cigarette
smoking, should be kept sufficiently far away from
the site of installation, repairing, removing and dis-
posal, during which refrigerant can possibly be
released to the surrounding space. Prior to work ta-
king place, the area around the equipment is to be
surveyed to make sure that there are no flammable
hazards or ignition risks. "No Smoking" signs shall
be displayed.
Ventilated area
Ensure that the area is in the open or that it is
adequately ventilated before breaking into the sy-
stem or conducting any hot work. A degree of ve-
ntilation shall continue during the period that the
work is carried out. The ventilation should safely
disperse any released refrigerant and preferably
expel it externally into the atmosphere.
Checks to the refrigeration equipment
Where electrical components are being changed,
they shall be fit for the purpose and to the correct
specification. At all times the manufacturer’s mai-
ntenance and service guidelines shall be followed.
If in doubt, consult the manufacturer s ’ technical
department for assistance.
The following checks shall be applied to installations
using flammable refrigerants:
--- The actual refrigerant charge is in accordance
with the room size within which the refrigerant
containing parts are installed;
--- The ventilation machinery and outlets are op-
erating adequately and are not obstructed;
--- If an indirect refrigerating circuit is being used,
the secondary circuit shall be checked for the pr-
esence of refrigerant;
--- Marking to the equipment continues to be visi-
ble and legible. Markings and signs that are illeg-
ible shall be corrected;
--- Refrigeration pipe or components are installed
in a position where they are unlikely to be exposed
to any substance which may corrode refrigerant
containing components, unless the components
