Carrier 38QUS014D8S2 Series, Service Manual

Page: 5 / 88

3
2 Information servicing
1.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, the following precautions shall be complied
with prior to conducting work on the
system.
2. 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.
3. 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 confined spaces
shall be avoided. The area around the
work space shall be sectioned off. Ensure that the
conditions within the area have been
made safe by control of flammable material.
4. 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
flammable atmospheres. Ensure that the
leak detection equipment being used is suitable for
use with flammable refrigerants, i.e. no
sparking, adequately sealed or intrinsically safe.
5. Presence of fire extinguisher
If 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.
6. No ignition sources
No person carrying out work in relation to a
refrigeration system which involves exposing
any pipe work that contains or has contained
flammable refrigerant 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 flammable 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.
7. 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.
8. 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. If in doubt consult the manufacturer's
technical department for assistance. The following
checks shall be applied to installations using
flammable refrigerants:


the charge size 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;

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.
9. 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 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 there no live electrical components and
wiring are exposed while charging, recovering or
purging the system;


that there is continuity of earth bonding.