Mitsubishi Electric PUHY-200YMF-B Service Handbook page 89

(5) Refrigerant Amount Adjustment Mode Operations (PURY-(P)200·250YMF-B)
1) Procedure
Follow the procedure shown below when needs to additionally replenish or discharge refrigerant arises depending
on operation status.
When turning on function select switch (SW2-4) on outdoor unit control circuit board, mode is changed to
refrigerant amount adjustment mode followed by the operations shown in the table below.
During cooling-only operations only, LEV3of BC controller is set at fixed opening, with outdoor
1
unit heat exchanger fully operated (SV3-5 open, SV6 close).
Operations
During heating-only operations (or cooling/heating mixed operations), normal operation is
2
observed.
In addition when setting selfdiagnosis switch (SW1) on control circuit board of outdoor unit to
liquid level of accumulator is shown by position of LED light-up.
When LED1 lights up → AL = 0 (No liquid in accumulator)
When LED2 lights up → AL = 1 (Liquid in accumulator)
When LED3 lights up → AL = 2 (Overcharge)
Note 1: Though AL=1 is shown for a while after starting operations in refrigerant amount adjustment mode, it some-
times changes to AL=0 as time goes by (when refrigerant system becomes stable).
1 In the case of genuine AL=1
In case AL=1, subcool of BC controller is 5 degrees or more, and SH of all indoor units are within 5-9
degrees.
2 In case the present AL=1 status will possibly change to AL=0
In case subcool of BC controller is 5 degrees or less, or SH of at least one indoor units 5 degrees or less.
2: Refrigerant amount adjustment in cooling mode can not be performed when high pressure is 14kg/cm
(1.37MPa) or more. In this case, perform the adjustment in heating mode.
A
B
Countermeasure
C
In the case of cooling-only operations in refrigerant amount adjustment mode, if the above 2
is applicable, judge accumulator level (AL) after subcool of BC controller reaches 5 deg or
more, and SH of all indoor units becomes 5~7 degrees.
Monitor subcool of BC controller at LED light-up position, by turning on selfdiagnosis switch
of outdoor unit (SW1-1, 2, 4, 8)
Monitor SH of indoor unit at LED light-up position, by turning on No. 1 unit SW1 -5, 6, 8
No. 2 unit SW1 -1, 5, 6, 7 and No. 3 unit SW1 -2, 5, 6, 8 No. 4 Unit SW1 -1, 2, 5, 6, 8
No. 5 unit SW1 -3, 5, 6, 8 No. 6 unit SW1 -1, 3, 5, 6, 8, No. 7 unit SW1 -1, 2, 3, 5, 6, 8,
No. 8 unit SW1 -4, 5, 6, 8 No. 9 unit SW1 -1, 4, 5, 6, 8, No. 10 unit SW1 -2, 4, 5, 6, and 8.
–87–
for PU(H)Y-(P)200·250YMF-B
1 2 3 4 5 6 7 8 9 10
ON
2
G