V 01/22
35
Specialist’s Manual
Aptitude requirement for maintenance man (repairs. should be done only be specialists).
a) 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 competence to handle
refrigerants safely in accordance with an industry recognised assessment specifìcation.
b) Servicing shall only be performed as recommended by the equipment manufacturer. Maintenance and repair
requiring the assistance of other skilled personnel shall be carried out under the supevision of the person
competent in the use of flammable refrigerants.
Safety preparation work
The maximum refrigerant charge amount is shown on the following table a
(Note: Please referto the nameplate for the charging quantity of R290)
Room area (m2)
4
11 15
Maximum charge (kg)
<0.152 0.225
0.304
table a - Maximum charge (kg)
Prior to beginning work on systems containing flammable refrigerants, safety checks are necessary to ensure
that the risk of ignition is minimised. For repair to the refrigerating system, the following precautions shall be
complied with prior to conducting work on the system.
Work
procedure
Work shall be undertaken under a controlled procedure so as to minimise the risk of a flammable gas or vapour
being present while the work is being performed.
General work area
AII 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 refrigerant detector prior to and during work, to ensure the
technician is aware of potentially toxic or flammable atmospheres. Ensure that the leak detection equipment
being used is suitable for use with all applicable refrigerants, i.e. non-sparking, adequately sealed or intrinsically
safe.
Presence of fire extinguisher
lf any hot work is to be conducted on the refrigeration equipment or any associated parts, appropriate fire
extinguishing equipment shall be available to hand. Have a dry powder or CO2 fire extinguisher adjacent to the
charging area.
No ignition sources
No person carrying out work in relation to a refrigeration system which involves exposing any pipe work shall
use any sources of ignition in such a manner that it may lead to the risk of fire or explosion. AII possible ignition
sources, including cigarette smoking, should be kept sufficiently far away from the site of installation, repairing,
removing and disposal, during which refrigerant can possibly be released to the surrounding space. Prior to
work taking piace, 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 system or
conducting any hot work. A degree of ventilation 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 tohe correct specification.
At all times the manufacturer's maintenance and service guidelines shall be followed. lf 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 operating adequately andare not obstructed;
---lf an indirect refrigerating circuit is being used, the secondary circuit shall be checked for the presence of
refrigerant;
---Marking to the equipment continues to be visible and legible. Markings and signs that are illegible 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 are constructed of
materials which are inherently resistant to being corroded or are suitably protected against being so corroded.
