Mitsubishi Electric PU(H)Y-P250YGM-A, Service Handbook

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Read Before Servicing ]
[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.
1. Items to be strictly observed
ΠPressurize the equipment with nitrogen up to the design pressure (4.15MPa), and then judge the equipment's air tight-
ness, taking temperature variations into account.
ΠWhen using refrigerant instead of a leak detector to find the location of a leak, use R410A.
ΠRefrigerant R410A must be charged in its liquid state (vs. gaseous state).
2. Reasons
ΠOxygen, if used for an air tightness test, poses a risk of explosion. (Only use nitrogen to check air tightness.)
ΠRefrigerant 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, R407C) leak.
Halide torch R22 leakage detector
NO NO