19
GB
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. non-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.
7. Repairs to sealed components
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 isabsolutely 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.
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 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 effectiveness of some types of leak detection equipment. Intrinsically
safe components do not have to be isolated prior to working on them.
8. 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 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.
9. Cabling
Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any other adverse
