Mitsubishi Electric PUHY-HP72 Service Handbook page 116

[6-3 Evaluating and Adjusting Refrigerant Charge ]
Keep the unit running for 5 minutes after
adjusting the refrigerant amount to
determine its adequacy.
Note 2
Gradually add refrigerant from
the service port on the low
pressure side.
Keep the unit running for 5 minutes after adjusting the
refrigerant amount to determine its adequacy.
Gradually add refrigerant from
the service port on the low
pressure side.
For information about Notes 1 through 4 in the flowchart, refer to items 1) through 4) on the previous page.
CAUTION
Do not release the extracted refrigerant into the air.
CAUTION
Charge liquid refrigerant (as opposed to gaseous refrigerant) into the system.
If gaseous refrigerant is charged into the system, the composition of the refrigerant in the cylinder will change and may
result in performance loss.
HWE18240_GB
Start
Turn on SW4 (922) on the OC.
Put all indoor units in the test run mode
and run the units in cooling mode.
Has the initial start-up
mode been completed?
YES
Has it been at least
30 minutes since
start up?
YES
Is the TH4 value of the OC, OS1,
OS2 at or below 100°C [212°F]?
N 1
ote
YES
Has the operating frequency
of the compressor on the OC, OS1,
and OS2 become stable?
Note 3
YES
Does 8°C [46.4°F] Tc-TH3 12°C [53.6°F] hold true?
(Use the largest "Tc - TH3" value of the
OC, OS1, and OS2.)
Note 1
YES
NO
Does TH2-Te 10°C [50°F] hold true?
(Check this item on the unit whose "Tc – TH3" value was
used in the step above.)
Note 1
YES
Note 2
NO
Is the TH4 value of the OC, OS1,
OS2 at or below 95°C [203°F]
YES
Adjustment complete
Turn off SW4 (922) on the OC.
Note 4
YES
NO
NO
NO
Gradually add refrigerant from
NO
the service port on the low-
pressure side.
NO
NO
Keep the unit running for 5 minutes
after adjusting the refrigerant amount
and check(Tc-TH3)
Does the following hold true?
Tc-TH3 8°C [46.4°F]
YES
Gradually add refrigerant from Gradually draw out
the service port on the low refrigerant from the service
pressure side. port on the low pressure side.
Note 2
NO
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chapter 6 -