10. Instructions for service technicians
Information addressed to specialists. They serve only as guidance for qualified personnel.
Any person involved in opening or draining the system should have a current and valid certificate confirming their competence to safely handle
flammable refrigerants.
1. Preparation for safe work
Before starting work on systems containing flammable refrigerants, a safety check should be carried out to minimize the risk of ignition. When repairing the
refrigeration system, the following precautions must be followed before working on the system.
2. Work procedure
The work should be carried out in accordance with a controlled procedure, which will minimize the risks associated with the presence of flammable gas or vapor
during the activity.
3. General work area
Service personnel and others working in the vicinity should be briefed on the type of service work to be performed. Avoid working in confined spaces. The area
around the workplace should be separated. Make sure the area is safe, i.e. no flammable materials are present.
4. Check for the presence of refrigerant
The area should be checked with a suitable refrigerant leak detector before and during the work so that the service technician is aware of working in a potentially
hazardous atmosphere. Make sure that the leak detector used for leak detection is suitable for all refrigerants used, i.e. non-sparking, properly sealed or inherently
safe.
5. Fire extinguisher availability
If work, involving the use of a torch, is to be performed on refrigeration equipment or related components, appropriate fire extinguishing equipment (i.e. CO2 powder
or carbon dioxide extinguisher) should be on hand.
6. No sources of ignition
No person carrying out work on the refrigeration system, that involves exposing the piping, should use any source of ignition in a way that could lead to fire or
explosion. Any potential sources of ignition should be kept away from any installation, repair, disassembly or disposal where there is a risk of release to the
environment. Before starting work, assess the area around the unit for potential hazards from flammable materials or sources of ignition. "No Smoking" signs must be
posted.
7. Area ventilation
Ensure that the area is open and sufficiently ventilated before starting any work involving the opening of the system or work involving the use of a torch. Adequate
ventilation must be ensured during the work. Ventilation should safely and effectively disperse the refrigerant and optimally discharge it to the outside to the
atmosphere.
8. Control of refrigeration equipment
When replacing electrical parts, use components that are suitable for the application and comply with the specifications. The manufacturer's maintenance and service
instructions must be followed at all times.
If in doubt, consult the manufacturer's technical department.
For systems using flammable refrigerants, check:
• whether the amount of refrigerant corresponds to the area of the room where the refrigerant-containing components are installed;
• that the ventilation devices are working properly and their air outlets are not blocked;
• whether the secondary circuit contains refrigerant when using an indirect refrigeration system;
• whether the markings on the devices remain visible and legible. Illegible markings and symbols should be corrected;
• that pipes or components containing refrigerant are installed in a position that prevents them from being exposed to corrosive substances, unless the components
are made of corrosion-resistant materials or are suitably protected against corrosion.
9. Control of electrical devices
Repair and maintenance of electrical components should include initial safety checks and component inspection procedures. If there is a fault that could compromise
safety, do not connect the power supply until the problem is solved. If the fault cannot be rectified immediately and operation must be resumed, an appropriate
temporary solution must be applied. The owner of the device should be informed about the situation so that people around are aware of it.
The initial security check requires checking:
• whether the capacitors have been discharged; the operation must be carried out in such a way as to avoid sparking;
• that no electrical components or wiring are exposed during refrigerant charging and recovery or purging the system;
• that grounding is provided.
10. Repairs to sealed components
When repairing sealed components, disconnect all electrical connections to the unit before removing the sealing covers, etc. If electrical power to the unit is required
during maintenance, then a continuously operating leak detection form should be placed at the most critical point to warn of a potentially hazardous situation.
When working with electrical components, care must be taken to ensure that the enclosure is not altered in a way that may affect its safety level. This includes
damage to electrical wires, excessive number of connections, connections not made in accordance with the technical specification, damage to seals, incorrect
adjustment of glands, etc.
• Make sure that the device is properly mounted.
• Make sure that gaskets or sealing materials are not worn to the extent that they cannot perform their function. Spare parts should comply with the manufacturer's
technical data.
Attention!
The use of a silicone sealant may reduce the effectiveness of some leak detection equipment. Elements that are safe in themselves do not need to be
insulated before starting work.
11. Repair of safe components
Do not apply any permanent inductive or capacitive loads without making sure that they do not exceed the permissible voltage and current values. Safe components
are the only types of components that can be worked on under voltage in a flammable atmosphere. Testing equipment should be properly rated. Components should
only be replaced with parts specified by the manufacturer. The use of other parts may cause the refrigerant to ignite due to leakage.
12. Wiring
Make sure that the wiring will not be exposed to wear, corrosion, excessive pressure, vibration, sharp edges or other undesirable factors. Inspection should also
consider the effects of time or constant vibration from sources such as compressors or fans.
13. Detecting the presence of flammable refrigerants
Under no circumstances should potential sources of ignition be used to detect or search for refrigerant leaks. Do not use a halogen torch (or other open flame
detectors).
14. Leak detection methods
The following leak detection methods are considered acceptable for refrigeration systems containing flammable refrigerants. Electronic detectors can be used to
detect refrigerant leaks. However, their sensitivity may be insufficient or they may need to be recalibrated. (Calibrate leak detection equipment in a refrigerant-free
area.) Make sure that the detector is not a potential source of ignition and is suitable for the refrigerant used. Leak detection equipment should be set to the lower LFL
percentage of the refrigerant and calibrated for the refrigerant used. The appropriate gas percentage (25% maximum) must also be confirmed.
