
10 11
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 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.
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
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
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
9. 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.
10. 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
11. Leak Detection Methods
for the refrigerant used. Leak detection equipment shall be set at a percentage of the LFL of the refrigerant and shall be calibrated to
use with most refrigerants but the use of detergents containing chlorine shall be avoided as the chlorine may react with the refrigerant
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.
12. Removal and Evacuation
When breaking into the refrigerant circuit to make repairs or for any other purpose conventional procedures shall be used.
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.
Important Safety Instructions Important Safety Instructions
The following procedure shall be adhered to: Remove refrigerant; Purge the circuit with inert gas; Evacuate; Purge again with inert gas;
Open the circuit by cutting or brazing.
safe. This process may need to be repeated several times. Compressed air or oxygen shall not be used for this task. Flushing shall be
any ignition sources and there is ventilation available.
13. Charging procedures
In addition to conventional charging procedures, the following requirements shall be followed. Ensure that contamination of different
refrigerants does not occur when using charging equipment. Hoses or lines shall be as short as possible to minimise the amount of
refrigerant contained in them.
Cylinders shall be kept upright.
Ensure that the refrigeration system is earthed prior to charging the system with refrigerant.
Label the system when charging is complete (if not already).
The system shall be leak tested on completion of charging but prior to commissioning. A follow up leak test shall be carried out prior
to leaving the site.
14. Decommissioning
Before carrying out this procedure, it is essential that the technician is completely familiar with the equipment and all its detail. It is
recommended good practice that all refrigerants are recovered safely. Prior to the task being carried out, an oil and refrigerant sample
the task is commenced.
a) Become familiar with the equipment and its operation.
b) Isolate system electrically.
c) Before attempting the procedure ensure that: Mechanical handling equipment is available, if required, for handling refrigerant
cylinders; All personal protective equipment is available and being used correctly; The recovery process is supervised at all times
by a competent person; Recovery equipment and cylinders conform to the appropriate standards.
d) Pump down refrigerant system, if possible.
e) If a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts of the system;
f) Make sure that cylinder is situated on the scales before recovery takes place.
g) Start the recovery machine and operate in accordance with manufacturer’s instructions.
i) Do not exceed the maximum working pressure of thecylinder, even temporarily.
removed from site promptly and all isolation valves on the equipment are closed off.
k) Recovered refrigerant shall not be charged into another refrigeration system unless it has been cleaned and checked.
15. Labelling
16. Recovery
When removing refrigerant from a system, either for servicing or decommissioning, it is recommended good practice that all
refrigerants are removed safely. When transferring refrigerant into cylinders, ensure that only appropriate refrigerant recovery cylinders
are employed. Ensure that the correct number of cylinders for holding the total system charge is available. All cylinders to be used
are designated for the recovered refrigerant and labelled for that refrigerant (i.e. special cylinders for the recovery of refrigerant).
are evacuated and, if possible, cooled before recovery occurs. The recovery equipment shall be in good working order with a set of
couplings and in good condition. Before using the recovery machine, check that it is in satisfactory working order, has been properly
maintained and that any associated electrical components are sealed to prevent ignition in the event of a refrigerant release. Consult
manufacturer if in doubt. The recovered refrigerant shall be returned to the refrigerant supplier in the correct recovery cylinder, and
the relevant Waste Transfer Note arranged. Do not mix refrigerants in recovery units and especially not in cylinders. If compressors
refrigerant does not remain within the lubricant. The evacuation process shall be carried out prior to returning the compressor to
the suppliers. Only electric heating to the compressor body shall be employed to accelerate this process. When oil is drained from a
system, it shall be carried out safely.