Refrigerant Amount Adjust Mode - Mitsubishi Electric PQHY-P200YLM-A Service Handbook

[ VIII Test Run Mode ]

[5] Refrigerant Amount Adjust Mode

1. Procedures <PQHY>
Follow the procedures below to add or extract refrigerant as necessary depending on the operation mode.
When the function switch SW4 No.922 (SW6-10: ON) on the main board on the heat source unit (OC only) is turned to ON,
the unit goes into the refrigerant amount adjust mode, and the following sequence is followed.
1) SW4-3 on the OS is invalid, and the unit will not go into the refrigerant amount adjust mode.
2) Refer to the relevant sections of the manual for how to set SW4 on the control board.(page 152)
Operation
When the unit is in the refrigerant amount adjust mode, the LEV on the indoor unit does not open as fully as it nor-
mally does during cooling operation to secure subcooling.
1) Adjust the refrigerant amount based on the values of TH4, TH3, TH6, and Tc, following the flowchart below. Check the TH4,
TH3, TH6, and Tc values on the OC, OS1, and OS2 by following the flowchart. The TH4, TH3, TH6, and Tc values can be
displayed by setting the self-diagnosis switch SW4 (SW6-10: OFF) on the main board on the OC, OS1, and OS2.
2) There may be cases when the refrigerant amount may seem adequate for a short while after starting the unit in the refrigerant
amount adjust mode but turn out to be inadequate later on (when the refrigerant system stabilizes).
When the amount of refrigerant is truly adequate.
TH3-TH6 on the heat source unit is 5°C [9°F] or above and SH on the indoor unit is between 5 and 15°C [9 and 27°F].
The refrigerant amount may seem adequate at the moment, but may turn out to be inadequate later on.
TH3-TH6 on the heat source unit is 5°C [9°F] or less and SH on the indoor unit is 5°C [9°F] or less.
Wait until the TH3-TH6 reaches 5°C [9°F] or above and the SH of the indoor unit is between 5 and 15°C [9 and 27°F] to
determine that the refrigerant amount is adequate.
3) High pressure must be at least 2.0MPa[290psi] to enable a proper adjustment of refrigerant amount to be made.
4) Refrigerant amount adjust mode automatically ends 90 minutes after beginning. When this happens, by turning off the SW4
No.922 (SW6-10: ON) and turning them back on, the unit will go back into the refrigerant amount adjust mode.
ON
2 3 4 5 6 7 8 9 10
1
HWE15060
Self-diagnosis swithes on TH4
ON
1 2 3 4 5 6 7 8 9 10
Self-diagnosis swithes on TH6
ON
2 3 4 5 6 7 8 9 10
1
The figure at left shows that the switches 1 through 5 are set to ON and 6 through 10 are set to OFF.
Self-diagnosis swithes on TH3
ON
1 2 3 4 5 6 7
Self-diagnosis swithes on Tc
ON
1 2 3 4 5 6 7
- 199 -
8 9 10
8 9 10
GB