Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 124

PUHY-(P) 600·650·700·750 YSMF-C
After adjusting the refrigerant,
operate for 5 minutes and determine.
Use the low-pressure service
port to charge the refrigerant
a little at a time.
After adjusting the refrigerant,
operate for 5 minutes and determine.
Use the low-pressure service
port to drain out refrigerant
a little at a time.
Note: 1 Convert Tc to saturation temperature Tc using the variable capacity unit high-pressure saturation temperature conversion
chart. Determine Tc-TH5, Tc-TH7 on the variable capacity unit.
Note: 2 Please perform Td determination on both the variable and constant capacity units.
Td: Variable capacity unit ........ TH11, TH12 (Turn all SW4-2 OFF to display these temperature data)
Constant capacity unit. ..... TH11 (Turn SW4-2 ON to display these temperature data)
Note: 3 Perform this adjustment while both the variable and constant capacity units are in operation.
The constant capacity unit compressor will not operate before the initial start mode is finished.
• Do not let the drained out refrigerant escape into the atmosphere.
• Always be sure to charge with refrigerant from the liquid phase side. (R407C)
Start adjustment
All indoor units begin cooling operations in
test run mode. Both constant and variable
capacity units are operated.
Over 6 minutes have
passed since variable and
constant capacity unit startup.
AL1 and AL2 are
0 or 1.
Is Td 115°C ?
Note: 2
Has the frequency
stabilized two hours or more
after the power has been turned on
or after 30 minutes of continuous
compressor operation after
the power has been
turned on?
Caution:
Note: 1
Is 5 Tc – TH5 10°C ?
Tc – TH7 20°C ?
Is Td 110°C ?
Note: 2
Adjustment finished.
-121-
AL1: Variable capacity unit liquid level AL
AL2: Constant capacity unit liquid level AL
Note: 3
Use the low-pressure service
port of AL ≠ 0 or 1 unit to
drain out refrigerant a little at
a time.
Use the low-pressure service
port of Td > 115°C unit to
charge the refrigerant a little
at a time.
After adjusting refrigerant,
operate for 5 minutes and
determine Tc – TH5.
Tc – TH5 < 5°C ?
Use the low-pressure
service port to charge
the refrigerant a little
at a time.
YES
NO
Use the low-pressure
service port to drain
out refrigerant a little
at a time.