Mitsubishi Electric CITY MULTI PQRY-P200YMF-B Service Handbook page 76

3) Refrigerant adjustment in heating season
1 Flow chart
Adjustment start
Heating operations of all indoor
units in test run mode.
Note 1
After compressor start, turn on
refrigerant amount adjustment
switch (SW2-4) of heat source
unit multi board.
Note 2
Operations stabilized?
Note 3
Liquid level of
accumulator indicates
AL=0?
Note 5
Charge refrigerant little by little
from low pressure service port.
10 minutes or more past after
refrigerant charge.
Liquid level of
accumulator indicates
AL=0?
Finish refrigerant.
Note 6
Calculate difference (W)
between refrigerant amounts
required for heating and
cooling, and replenish the
calculated refrigerant amount.
Turn off refrigerant amount
adjustment switch (SW2-4), and
perform normal operations for
about 15-minute.
Turn on No. 7 selfdiagnosis
switch (SW1) so as to be in LED
liquid level display mode.
Liquid level of
accumulator indicates
AL=1?
Turn off all SW1
Adjustment finished
* Valid for only 2 hours in the test run mode. All work must therefore be carried out within 2
hours. Select the test run mode again if more than 2 hours is required.
* The coolant volume adjustment mode extends for 2 hours after SW2-4 is set to ON. All work
must therefore be carried out within 2 hours. Switch SW2-4 OFF → ON if more than 2 hours is
required.
Liquid level of
accumulator indicates
AL=1?
Refrigerant
insufficient for one
unit operations?
Charge refrigerant little by little
from low pressure service port.
Liquid level
changed from AL=1
to AL=0?
Finish refrigerant.
Re-adjustment
–73–
YES
NO
Note 3
Note 4
Adjustment not
required.
Note 5
Recover refrigerant little by little
from low pressure Ball valve
(BV1) service port.
changed from AL=1
Suspend refrigerant purge.
Recover about 2kg refrigerant
by setting refrigerant recover
time as a standard.
Turn off refrigerant amount
adjustment switch (SW2-4).
Note 5
Liquid level
to AL=0?
Note 8
Adjustment
finished