Mitsubishi Electric PUHY-200YMF-B Service Handbook page 84

3) Refrigerant Volume Adjustment Mode Operation
2 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.
Switching the function select switch (SW2-4), located on the outdoor unit's control board, ON starts refrigerant
1
volume adjustment mode operation and the following operation occurs.
1
Operation
2
Additionally, if the self-diagnosis switch (SW1) on the outdoor unit's control board is set to
2
accumulator's liquid level is indicated by the LED lighting position.
AL = 0 (No liquid in accumulator)
AL = 1 (Liquid in accumulator)
AL = 2 (Overcharge)
Notes 1 Even if AL = 1 for a short time after operation in the refrigerant volume adjustment mode starts, as
time passes (as the refrigeration system stabilizes), it may change to AL = 0.
1 If it is really AL = 1
Cases where AL = 1, TH5 - TH7 in the outdoor unit is 5 deg or greater and the SH of all indoor units is 6~13 deg.
2 Cases where AL = 1 now, but there is a possibility that it will change to AL = 0 as time passes.
TH5 - TH7 in the outdoor unit is not 5 deg., or the SH of at least one of the indoor units is not deg.
Notes 2 A refrigerant volume adjustment performed in the cooling mode must be done with a gauge reading of 14 kg/cm
(1.37MPa) or higher.
If the pressure does not reach 14 kg/cm
Notes 3 In cases where a high pressure of 14 kg/cm
(20~25 deg.) in cooling mode operation, and high pressure changes at the border of 14 kg/cm
and Tc to adjust the refrigerant volume. TH1, TH5 and TH7 can be displayed using the self-diagnosis switch (SW1) on the outdoor
unit's control board.
Notes 4 Judgment by the AL is at best only a rough guideline. Please do not add refrigerant based on the
AL reading alone. (Be sure to obtain calculations of the correct amount before adding refrigerant.)
TH1 Self-diagnosis Switch
1 2 3 4 5 6 7 8 9 10
ON
TH7 Self-diagnosis Switch
1 2 3 4 5 6 7 8 9 10
ON
Using these, judge TH1, Tc - TH5 and Tc - TH7.
However, if you are adjusting the cooling refrigerant volume by this procedure, do not turn Dip SW2-4 ON.
In cases where cooling is being done in the refrigerant volume adjustment mode, if 2 above
applies, please perform accumulator level AL judgment after waiting until TH5 - TH7 in the
A
outdoor unit is at 5 deg or higher and the SH of all the indoor units reaches 6~9 deg.
Treatment
For the SH of indoor units, turn the self-diagnosis switch for the outdoor unit ON, then monitor by
C
the lighting position of the LED.
When supplementing the refrigerant volume, please be careful to charge with liquid refrigerant.
During cooling, LEV1 on the outdoor unit opens slightly wider than normal.
During heating, ordinary operation is carried out.
2
2
G (1.37MPa), adjust in the heating mode.
G (1.37MPa) or greater cannot be maintained with low temperature outside air
TH5 Self-diagnosis Switch
1 2 3 4 5 6 7 8 9 10
ON
Tc Self-diagnosis Switch
1 2 3 4 5 6 7 8 9 10
ON
–82–
for PU(H)Y-(P)200·250YMF-B
1 2 3 4 5 6 7 8 9 10
, the
ON
2
G
2
G (1.37MPa), use TH1, TH5, TH7