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2-4. Presence of fi re extinguisher
• If any hot work is to be conducted on the refrigerating equipment or any associated parts, appropriate fi re extinguishing equipment shall be
available at hand.
• Have a dry powder or CO
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fi re extinguisher adjacent to the charging area.
2-5. No ignition sources
• No person carrying out work in relation to a refrigerating system shall use any sources of ignition in such a manner that it may lead to the risk of
fi re or explosion. He/She must not be smoking when carrying out such work.
• All possible ignition sources, including cigarette smoking, should be kept suffi ciently far away from the site of installation, repairing, removing
and disposal, during which fl ammable 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 fl ammable hazards or ignition risks.
• “No Smoking” signs shall be displayed.
2-6.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.
2-7. Checks to the refrigerating equipment
• Where electrical components are being changed, they shall be fi t for the purpose and to the correct specifi cation.
• 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 fl ammable refrigerants.
- 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.
- Refrigerating 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 properly
protected against being so corroded.
2-8. Checks to electrical devices
• Repair and maintenance to electrical components shall include initial safety checks and component inspection procedures.
• Initial safety checks shall include but not limit to:-
- That capacitors are discharged: this shall be done in a safe manner to avoid possibility of sparking.
- That there are no live electrical components and wiring are exposed while charging, recovering or purging the system.
- That there is continuity of earth bonding.
• At all times the manufacturer’s maintenance and service guidelines shall be followed.
• If in doubt consult the manufacturer’s technical department for assistance.
• 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.
• The owner of the equipment must be informed or reported so all parties are advised thereinafter.
3. 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 potentially hazardous 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 specifi cation,
damage to seals, incorrect fi tting 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 fl ammable
atmospheres.
• Replacement parts shall be in accordance with the manufacturer’s specifi cations.
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.
4. 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 fl ammable atmosphere.
• The test apparatus shall be at the correct rating.
• Replace components only with parts specifi ed by the manufacturer. Unspecifi ed parts by manufacturer may result ignition of refrigerant in the
atmosphere from a leak.
5. 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.
6. Detection of fl ammable refrigerants
• Under no circumstances shall potential sources of ignition be used in the searching or detection of refrigerant leaks.
• A halide torch (or any other detector using a naked fl ame) shall not be used.
