Air Tightness Test - Mitsubishi Electric City Multi PQHY-P72 Service Handbook

[7] Air Tightness Test

No changes have been made in the detection method. Note that a refrigerant leak detector for R22 will not detect an R410A
leak.
NO
1. Items to be strictly observed
Pressurize the equipment with nitrogen up to the design pressure (4.15MPa[601psi]), and then judge the equipment's air
tightness, taking temperature variations into account.
When using refrigerant instead of a leak detector to find the location of a leak, use R410A.
Refrigerant R410A must be charged in its liquid state (vs. gaseous state).
2. Reasons
Oxygen, if used for an air tightness test, poses a risk of explosion. (Only use nitrogen to check air tightness.)
Refrigerant R410A must be charged in its liquid state. If gaseous refrigerant in the cylinder is drawn out first, the compo-
sition of the remaining refrigerant in the cylinder will change and become unsuitable for use.
3. Notes
Procure a leak detector that is specifically designed to detect an HFC leak. A leak detector for R22 will not detect an
HFC(R410A) leak.
Halide torch
NO
R22 leakage detector
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