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.
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 supply to equipment during servicing, then a permanently
operating form of leak detection shall be located at the most critical point to warn of a poten-
tially hazardous situation.
Particular attention shall be paid to the following to ensure that by working on electrical com-
ponents, 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 ori-
ginal specification, damage to seals, incorrect fitting of glands, etc.
Ensure that the apparatus is mounted securely.
Ensure that seals or sealing materials have not degraded to the point 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.
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 safe components are the only types that can be worked on while live in the pre-
sence of a flammable atmosphere. The test apparatus shall be at the correct rating.
Replace components only with parts specified by the 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, corrosion, 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 compressors or fans.
DETECTION OF FLAMMABLE REFRIGERANTS
Under no circumstances shall potential 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.
REMOVAL AND EVACUATION
When breaking into the refrigerant circuit to make repairs – or for any other purpose – co-
nventional procedures shall be used. However, for flammable refrigerants it is important that
best practice is followed since flammability is a consideration. The following procedure shall
be adhered to:
remove refrigerant;
purge the circuit with inert gas;
evacuate;
purge with inert gas;
open the circuit by cutting or brazing.