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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 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 refrig-
erant detector prior to and during work, to ensure the
technician is aware of potentially flammable atmos-
pheres. Ensure that the leak detection equipment
being used is suitable for use with flammable refriger-
ant, i.e.nonsparking, adequately sealed or intrinsi-
cally safe.
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.
No ignition sources
No person carrying out work in relation to a refriger-
ant 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 pos-
sible 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.
Ventilated area
Ensure that the area is in the open or that it is ade-
quately ventilated before breaking into the system or
conducting any hot wok. 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 mainte-
nance and service guidelines shall be followed. If in
doubt consult the manufacturer's technical depart-
ment for assistance.
The following checks shall be applied to installations
using flammable refrigerants:
– The charge size in accordance with the room size
within which the refrigerant containing parts are
installed;
– The ventilation machinery and outlets are operat-
ing adequately and are not obstructed
Checks to electrical devices
Repair and maintenance to electrical components
shall include initial safety checks and components
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 purg-
ing the system;
– that there is continuity of earth bonding
Repairs to sealed components
During repairs to sealed components, all electrical
supplies shall be disconnected from the equipment
being worked upon prior to any removal of sealed
covers, etc.
If it is absolutely necessary to have an electrical sup-
ply to equipment during servicing, then a permanently
operating form of leak detection shall be located at
the most critical point to warn of a potentially hazard-
ous situation.
Particular attention shall be paid to the following to
ensure that by working on electrical components, the
casing is not altered in such a way that the level of
protection is affected. This shall include damage to
cables, excessive number of connections, terminals
not made to original specification, damage to seals,
incorrect fitting of glands, etc.
Ensure that apparatus is mounted securely.
Ensure that seals or sealing materials have not
degraded such that they no longer serve the purpose
of preventing the ingress of flammable atmospheres,
Replacement parts shall be in accordance with the
manufacturer's specifications.
NOTE The use of silicon sealant may inhibit the effec-
tiveness of some types of leak detection equipment.
Intrinsically safe components do not have to be iso-
lated prior to working on them.
Repair to intrinsically safe components
Do not apply any permanent inductive or capacitance
loads to the circuit without ensuring that this will not
exceed the permissible voltage and current permitted
for the equipment in use.
Intrinsically components are the only types that can
be worked on while live in the presence of a flamma-
ble atmosphere. The test apparatus shall be at the
correct rating.
Replace components only with parts specified by
manufacturer. Other parts may result in the ignition of
refrigerant in the atmosphere from a leak.
Cabling
Check that cabling will not be subject to wear, corro-
sion, excessive pressure, vibration, sharp edges or
any other adverse environmental effects. The check
shall also take into account the effects of aging or
continual vibration from sources such as compres-
sors or fans.
Detection of flammable refrigerants
Under no circumstances shall potentially sources of
ignition be used in the searching for or detection of
refrigerant leaks. A halide torch (or any other detector
using a naked flame) shall not be used.
GB
37
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