Mitsubishi Electric CITY MULTI PUHY-P200YEM-A Service Handbook page 58

2 PURY-P200·250
1) Starting of defrost operations
• After integrated 43 minutes of compressor operations, defrosting operations start when –10˚C
or less of piping temperature (TH7) is detected for 3 consecutive minutes.
• Forcible defrosting operations start by turning on forcible defrost switch (SW2-7) if 10 minutes have already elapsed
after compressor start or completion of defrosting operations and will last for 10 mins.
• Defrost prohibit timer munimum from 43 minutes to 90 minutes by setting SW2-8 "ON".
Defrost will last a maximum of 15 minutes, the next defrost time will be 39 minutes.
2) Completion of defrosting operations
Defrosting operations stop when 10 minutes have passed since start of defrosting operation, or piping temperature
(TH5 and TH7) reaches10˚C or more
(Defrosting operations do not stop for 4 minutes after starting, except when piping temperature exceeds (TH5 and TH7)
25˚C.
3) Defrosting prohibition
Defrosting operations do not start during oil recovery, and for 3 min utes after starting compressor.
4) Trouble during defrosting operations
When trouble is detected during defrosting operations, the defrosting operations stop, and defrosting prohibition
time decided by integrated operation time of compressor is set to be 20 minutes.
5) Change in number of operating indoor units during defrosting operations
• In case number of operating indoor units changes during defrosting operations, the defrosting operations continue,
and control of unit number change is performed after the defrosting operations are finished.
• Even in case all indoor units stop or thermostat is turned off during defrosting operations, the defrosting operations
do not stop until e xpected defrosting activities are completed.
(7) Judgment of Refrigerant amount
Accumulator design
Cooling
Compressor
Frequency
TdsH
40 < TdSH
- -
35 < TdSH < 40
- -
- -
20 < TdSH < 35
- - - -
10 < TdSH < 20
- -
- -
TdSH < 10
- -
Heating
TH5/TH7
TH5/TH7 5°C
TdsH
80 < TdSH
- -
60 < TdSH < 80
- - - -
40 < TdSH < 60
- - - -
10 < TdSH < 40
- - - -
TdSH < 10
- -
Note 1 TH5 - Y-Series
TH7 - R2-Series
2 TdSH=Discharge Super Heat.
=Td-Tsg ( low pressure saturation temperature)
.
20~45Hz 46~70Hz
AL=0 AL=0
AL=1 AL=0
AL=1 AL=1
AL=1 AL=1
AL=2 AL=2
5°C < TH5/TH7 15°C
- -
AL=0
AL=0
AL=1
AL=0
AL=1 AL=1
AL=1
AL=1
AL=2
AL=2
71Hz~Fmax
AL=0
AL=0
AL=0
AL=1
AL=2
15°C < TH5/TH7
- -
AL=0
AL=0
AL=0
AL=1
AL=2
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