CS-MZ20UD3EA — Panasonic Air Conditioner Service Manual (repair manual). Page 6

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2. Precaution for Using R32 Refrigerant 
  The basic installation work procedures are the same as conventional refrigerant (R410A, R22) models. 
However, pay careful attention to the following points: 
Since the working pressure is higher than that of refrigerant R22 models, some of the piping and installation and service tools are 
(See “2.1. Special tools for R32 (R410A)”.) 
Especially, when replacing a refrigerant R22 model with a new refrigerant R32 model, always replace the conventional piping and flare 
nuts with the R32 and R410A piping and flare nuts on the outdoor unit side. 
For R32 and R410A, the same flare nut on the outdoor unit side and pipe can be used. 
Models that use refrigerant R32 and R410A have a different charging port thread diameter to prevent erroneous charging with refrigerant 
R22 and for safety. 
Therefore, check beforehand. [The charging port thread diameter for R32 and R410A is 12.7 mm (1/2 inch).] 
Be more careful than R22 so that foreign matter (oil, water, etc.) does not enter the piping. 
Also, when storing the piping, securely seal the opening by pinching, taping, etc. (Handling of R32 is similar to R410A.) 
Installation (Space) 
Must ensure the installation of pipe-work shall be kept to a minimum. Avoid use dented pipe and do not allow acute bending. 
Must ensure that pipe-work shall be protected from physical damage. 
Must comply with national gas regulations, state municipal rules and legislation. Notify relevant authorities in accordance with all 
applicable regulations. 
Must ensure mechanical connections be accessible for maintenance purposes. 
In cases that require mechanical ventilation, ventilation openings shall be kept clear of obstruction. 
When disposal of the product, do follow to the precautions in #12 and comply with national regulations. 
Always contact to local municipal offices for proper handling. 
Interconnecting refrigerant pipework, i.e. pipework external to the unitary components, should be marked with a Class label (see 
Figure 9.1 of Code of Practice) every two metres where the pipework is visible. This includes pipework located in a ceiling space or 
any void which a person may access for maintenance or repair work within that space. 
2-1. Service personnel 
Any qualified person who is involved with working on or breaking into a refrigerant circuit should hold a current valid certificate from 
an industry-accredited assessment authority, which authorizes their competence to handle refrigerants safely in accordance with an 
industry recognised assessment specification. 
Servicing shall only be performed as recommended by the equipment manufacturer. Maintenance and repair requiring the 
assistance of other skilled personnel shall be carried out under the supervision of the person competent in the use of flammable 
Servicing shall be performed only as recommended by the manufacturer. 
2-2. Work 
Prior to beginning work on systems containing flammable refrigerants, safety checks are necessary to ensure that the risk of 
ignition is minimised. 
For repair to the refrigerating system, the precautions in #2-2 to #2-8 must be followed before conducting work on the system. 
Work shall be undertaken under a controlled procedure so as to minimize 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 and supervised on the nature of work being carried 
Avoid working in confined spaces. 
Wear appropriate protective equipment, including respiratory protection, as conditions warrant. 
Ensure that the conditions within the area have been made safe by limit of use of any flammable material. Keep all sources of 
ignition and hot metal surfaces away. 
2-3. Checking for presence of refrigerant 
The area shall be checked with an appropriate refrigerant detector prior to and during work, to ensure the technician is aware of 
potentially flammable atmospheres. 
Ensure that the leak detection equipment being used is suitable for use with flammable refrigerants, i.e. non sparking, adequately 
sealed or intrinsically safe. 
In case of leakage/spillage happened, immediately ventilate area and stay upwind and away from spill/release. 
In case of leakage/spillage happened, do notify persons downwind of the leaking/spill, isolate immediate hazard area and keep 
unauthorized personnel out. 
2-4. Presence of fire extinguisher 
If any hot work is to be conducted on the refrigeration equipment or any associated parts, appropriate fire extinguishing equipment 
shall be available at hand. 
Have a dry powder or CO
 fire extinguisher adjacent to the charging area. 
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