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• 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.
• Make sure that the exhaust port of the vacuum pump is not close to the ignition source and that ventilation is
possible.
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, installer 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 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.
10. 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 towarn 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
specification, damage to seals, incorrect fitting of glands, etc.
• Ensure that 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.
21-EN
– 11 –
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.
11. 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.
12. Cabling
• Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any
other adverse environmental effects.
• Check shall also take into account the effects of aging or continual vibration from sources such as
compressors or fans.
13. 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.
• Electronic leak detectors may be used to detect refrigerant leaks but, in the case of flammable refrigerants,
the sensitivity may not be adequate, or may need re-calibration. (Detection equipment shall be calibrated in
a refrigerant-free area.)
• Ensure that the detector is not a potential source of ignition and is suitable for the refrigerant used.
• Leak detection equipment shall be set at a percentage of the LFL of the refrigerant and shall be calibrated to
the refrigerant employed and the appropriate percentage of gas (25% maximum) is confirmed.
• Leak detection fluids are also suitable for use with most refrigerants but the use of detergents containing
chlorine shall be avoided as the chlorine may react with the refrigerant and corrode containing chlorine.
• If a leak is suspected, all naked flames shall be removed / extinguished.
• If a leakage of refrigerant is found which requires brazing, all of the refrigerant shall be recovered from the
system, or isolated (by means of shut off valves) in a part of the system remote from the leak.
14. Leak detection methods
• Electronic leak detectors shall be used to detect flammable refrigerants leak, but the sensitivity may not be
adequate, or may need re-calibration. (Detection equipment shall be calibrated in a refrigerant-free area.)
• Ensure that the detector is not a potential source of ignition and is suitable for the refrigerant used.
• Leak detection equipment shall be set at a percentage of the LFL of the refrigerant and shall be calibrated to
the refrigerant employed and the appropriate percentage of gas (25% maximum) is confirmed.
• Leak detection fluids are suitable for use with most refrigerants but the use of detergents containing chlorine
shall be avoided as the chlorine may react with the refrigerant and corrode the copper pipework.
• If a leak is suspected, all naked flames shall be removed / extinguished.
• If a leakage of refrigerant is found which requires brazing, all of the refrigerant shall be recovered from the
system, or isolated (by means of shut off valves) in a part of the system remote from the leak.
• Oxygen free nitrogen (OFN) shall then be purged through the system both before and during the brazing
process.
15. Removal and evacuation
• When breaking into the refrigerant circuit to make repairs or for any other purpose, Conventional procedures
shall be used. However, 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;
22-EN
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