83
Installation and Maintenance
Service Manual
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.
● Initial safety checks shall include:
— that capacitors are discharged: this shall be done in a
safe manner to avoid possibility of sparking;
— that no live electrical components and wiring are
exposed while charging, recovering or purging the system;
— that there is continuity of earth bonding.
● Checks to the area
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, DD.4.3 to DD.4.7 shall be completed 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 ammable gas or vapour being
present while the work is being performed.
● General work area
All maintenance staff and others working in the local area
shall be instructed on the nature of work being carried out.
Work in conned spaces shall be avoided.
● 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 ammable 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 re extinguisher
If any hot work is to be conducted on the refrigerating
equipment or any associated parts, appropriate fire
extinguishing equipment shall be available to hand. Have a
dry powder or CO
2
re extinguisher adjacent to the charging
area.
● No ignition sources
No person carrying out work in relation to a refrigerating
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. All 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 ammable
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 refrigerating equipment
Where electrical components are being changed, they shall
be t for the purpose and to the correct specication. At all
times the manufacturer's maintenance 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
ammable 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;
— if 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;
— refrigerating 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. If a fault exists that could compromise safety,
then no electrical supply shall be connected to the circuit
until it is satisfactorily dealt with. If the fault cannot be
corrected immediately but it is necessary to continue
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