Refrigerant Volume Adjustment Mode Operation - Mitsubishi Electric CITY MULTI P500YMF-C Service Handbook

[3] Refrigerant Volume Adjustment Mode Operation

(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.
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. (Refrigerant recovery mode and oil recovery
mode will be invalid.)
2
Additionally, if the LED monitor display switch (SW1) on the outdoor unit's control board is set to
the accumulator's liquid level is indicated by the LED lighting position.
AL = 0 (No fluid 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.
Notes 2 As the refrigerant volume can not be adjusted in the heating mode, retrieve the refrigerant, evacu-
ate air and then fill the specified volume of refrigerant if it is necessary to adjust the refrigerant
volume in the winter season.
Notes 3 A refrigerant volume adjustment performed in the cooling mode must be done with a gauge reading of 13 kg/cm
higher.
If the pressure does not reach this guage reading the refrigerant cannot be collected.
Therefore, collect used refrigerant and evacuate the unit completely, and then fill new refrigerant up to a specified
quantity.
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.)
Notes 5 When supplementing the refrigerant volume, please be careful to charge with liquid refrigerant.
TH1
1 2 3 4 5 6 7 8 9 10
ON
SC16
1 2 3 4 5 6 7 8 9 10
ON
SC11
1 2 3 4 5 6 7 8 9 10
ON
Pd (High pressure)
1 2 3 4 5 6 7 8 9 10
ON
–62–
1 2 3 4 5 6 7 8 9 10
ON ,
2 G or