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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 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 (fan and evaporator) 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.
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 presence of a flammable
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