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.
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. 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
.
Repairs to sealed components
DD.5.1 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 potentially hazardous situation.
DD.5.2 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 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.
