Refrigerant Volume Adjustment Mode Operation - Mitsubishi Electric CITY MULTI PUHY-P200YEM-A Service Handbook

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Refrigerant Volume Adjustment Mode Operation

1 PU(H)Y-(P)200·250·315
(1) Procedure
Depending on the operating conditions, it may be necessary either to charge with supplementary refrigerant, or to
drain out some, but if such a case arises, please follow the procedure given below flow chart.
Switching the function select switch (SW2-4), located on the outdoor unit's control board, ON starts
1
refrigerant volume adjustment mode operation and the following operation occurs. (Refrigerant recovery
mode and oil recovery mode will be invalid.)
Operation
Additionary, if the LED monitor display switch (SW1) on the outdoor unit's control board
2
is set to the composition of refrigerant circulating in the refrigeration cycle (
Note 1: Even if the refrigerant volume has reached a suitable level shortly after starting refrigerant volume
adjustment mode, if left for a sufficient length of time (once the refrigeration system has stabilized), there
are times when this level may become unsuitable.
1) The refrigerant volume is suitable.
When the refrigerant volume for TH5-TH7 is more than 5K at the outdoor unit, and 6 to 13K for SH at
the indoor unit.
2) The current volume is suitable, however, may become unsuitable after a certain length of time.
When the refrigerant volume for TH5-TH7 is less than 5K at the outdoor unit, or less than 6K for SH at
the indoor unit.
Note 2: There are times when it becomes difficult to determine the volume when performing refrigerant
adjustments if the high pressure exceeds 1.37MPa.
Note 3: Based on the following flowchart, use TH1, TH5, TH7 and Tc to adjust the refrigerant volume. Use the
self-diagnosis switch (SW1) on the outdoor unit main PCB to display TH1, TH5, TH7 and Tc.
TH1
1 2 3 4 5 6 7 8 9 10
ON
TH7
1 2 3 4 5 6 7 8 9 10
ON
Using these, judge TH1, Tc - TH5 and Tc - TH7.
When running refrigerant volume adjustment mode in the cooling operation, if note 2 above applies,
determine the suitable refrigerant volume after waiting until outdoor units TH 5-7 reach
A
more than 5K, and the indoor unit SH is in the range of 6 to 9K.
Turn on the outdoor unit self-diagnosis switch and then monitor the LED for the indoor unit SH.
C
The outdoor unit LEV1 diverges more than usual during cooling operation.
TH5
ON
Tc
ON
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 7 8 9 10
–77–
- 75 -
for PU(H)Y-(P)200·250·315
1 2 3 4 5 6 7 8 9 10
ON
OC).