Refrigerant Volume Adjustment Mode Operation - Mitsubishi Electric PURY-P200 Service Handbook

[5] Refrigerant Volume Adjustment Mode Operation

Since the refrigerant volume adjustment introduced in this chapter is just for emergency need, correct adjustment to
meet the rated refrigerant volume is difficult. Please judge for adequate volume by following the flow chart later under
normal operation mode.
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
(1) Switching the function select switch (SW2-4), located on the outdoor unit's control board, ON starts
refrigerant volume adjustment mode operation and the following operation occurs
1
Operation During cooling operation, the indoor unit LEV opening becomes slightly smaller than
the usual, and subcool can be easily procured.
2
During only cooling operation, balance oil, oil connection and refrigerant collection
controls become invalid.
3
During heating only and heating main operation, normal operation is conducted.
Notes: 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 subcools (SC11 and SC16) of the BC controller are 5K or more, and when SH of the indoor
unit is 5~15K.
2) The current volume is suitable, however, may become unsuitable after a certain length of time;
When the subcools (SC11 and SC16) of the BC controller are 5K or less, or when SH of the indoor unit
is 5K or less.
✻ In this case, after the subcool of the BC controller reaches 5K or more, and after SH of the indoor unit
reaches 5~15K, perform the judgment of the refrigerant adjustment.
✻ SC11: BC controller inlet liquid refrigerant subcool
SC16: BC controller outlet liquid refrigerant subcool
2. There are times when it becomes difficult to determine the volume when performing refrigerant adjustments if
the high pressure exceeds 2.0MPa.
3. Based on the following flowchart, use TH11 to adjust the refrigerant volume. Use the self-diagnosis switch
(SW1) on the outdoor unit main PCB to display TH11, SC11 and SC16.
4. Refrigerant adjustment mode operation will automatically stop in 90 minutes. By turning off and on SW 2-4,
the adjustment mode operation can be run again.
Self-diagnosis switch for TH11
1 2 3 4 5
ON
Self-diagnosis switch for SC16
1 2 3 4 5
ON
Using these, judge TH11, SC11 and SC16.
6 7 8 9 10
6 7 8 9 10
- 111 -
.
Self-diagnosis switch for SC11
1 2 3 4 5 6 7 8 9 10
ON