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REQUIREMENTS FOR OPERATION
Requirements for Operation, Service and Installation of Appliances Using
Flammable Refrigerants
General (cont.)
• that after completion of field piping for split systems, the field pipework shall be pressure tested with an inert
gas and then vacuum tested prior to refrigerant charging, according to the following requirements:
- The minimum test pressure for the low side of the system shall be the low side design pressure and the
minimum test pressure for the high side of the system shall be the high side design pressure, unless the
high side of the system, cannot be isolated from the low side of the system in which case the entire system
shall be pressure tested to the low side design pressure.
- The test pressure after removal of pressure source shall be maintained for at least 1 hour with no decrease
of pressure indicated by the test gauge, with test gauge resolution not exceeding 5% of the test pressure.
- During the evacuation test, after achieving a vacuum level specified in the manual or less, the refrigeration
system shall be isolated from the vacuum pump and the pressure shall not rise above 1500 microns within
10 min. The vacuum pressure level shall be specified in the manual, and shall be the lessor of 500 microns
or the value required for compliance with national and local codes and standards, which may vary between
residential, commercial, and industrial buildings.
• that field-made refrigerant joints indoors shall be tightness tested according to the following requirements:
The test method shall have a sensitivity of 5 grams per year of refrigerant or better under a pressure of at
least 0.25 times the maximum allowable pressure. No leak shall be detected.
Qualification of workers
The manual shall contain specific information about the required qualification of the working personnel for
maintenance, service and repair operations. Every working procedure that affects safety means shall only be
carried out by competent persons.
Examples for such working procedures are:
• breaking into the refrigerating circuit;
• opening of sealed components;
• opening of ventilated enclosures.
The competent persons are trained by the national training organizations or manufacturers that are accredited
to teach the relevant national competency standards that may be set in legislation. The achieved competence
should be documented by a certificate.
Information on servicing
Prior to beginning work on systems containing FLAMMABLE REFRIGERANTS, safety checks are necessary to
ensure that the risk of ignition is minimized. For repair to the REFRIGERATING SYSTEM, the below requirement
shall be completed prior to conducting work on the system:
– Work shall be undertaken under a controlled procedure so as to minimise the risk of a flammable gas or vapor
being present while the work is being performed.
– All maintenance staff and others working in the local area shall be instructed on the nature of work being
carried out. Work in confined spaces shall be avoided.
– The area shall be checked with an appropriate refrigerant detector prior to and during work, to ensure the
technician is aware of potentially toxic or flammable atmospheres. Ensure that the leak detection equipment
being used is suitable for use with all applicable refrigerants, i. e. non-sparking, adequately sealed or
intrinsically safe.
– If any hot work is to be conducted on the refrigerating 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.
31-5001074 Rev. 0
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