Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 123

(2) Refrigerant adjustment in cooling season (Flow chart)
PUHY-(P) 400·500 YMF-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.
Start adjustment
Set all indoor units to test run mode
and start cooling.
Is the liquid level
of the accumulator 0 or 1,
6 minutes or more after
starting?
Is TH1 115°C ?
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?
Note: 1
Is 5 Tc – TH5 10°C ?
Tc – TH7 20°C ?
Is TH1 110°C ?
Adjustment finished.
Caution:
Do not let the drained out refrigerant escape to the outside atmosphere.
• Always be sure to charge with refrigerant from the liquid phase side.(R407C)
-120-
Use the low-pressure service
port to drain out refrigerant
a little at a time.
Use the low-pressure service
port 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 Use the low-pressure
service port to charge service port to drain
the refrigerant a little out refrigerant a little
at a time. at a time.
YES
NO