27
V 02/22
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 refer to 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 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 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 to the 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 and are 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.
Checks to electrical devices
Repair and maintenance to electrical components shall include initial safety checks and component inspection
procedures. lf a fault exists that could compromise safety, then no electrical supply shall be connected to the circuit until
it is satisfactorily dealt with. lf the fault cannot be corrected immediately but it is necessary to continue operation, an
adequate temporary solution shall be used. This shall be reported to the owner of the equipment so all parties are
advised.
lnitial safety checks shall include:
---That capacitors are discharged: this shall be done in a safe manner to avoid possibility of sparking;