Refrigerant Recovery Control - Mitsubishi Electric PUHY-RP200 Service Handbook

[ VII Control ]
(3) Stopping the defrost operation
1) When SW3-4 is set to OFF
ŒThe defrost cycle ends when 12 minutes have passed since the beginning of the cycle, or when the pipe temperature (TH3),
in the following table, or above has been continuously detected for 4 minutes.
ŒDefrost operation will not stop its operation for 2 minutes once started unless the piping temperature exceeds 25°C [77°F]
within 2 minutes, in which case the operation will stop.
ŒIn the multiple-outdoor-unit system, defrosting is stopped on all units at the same time.
2) When SW3-4 is set to ON
ŒThe defrost cycle ends when 12 minutes have passed since the beginning of the cycle, or when the pipe temperature (TH3)
has been continuously detected for 2 minutes (when SW3-4 is set to OFF) that exceeds the values in the table below.
ŒThe defrost cycle will not end for two minutes once started unless the pipe temperature
(25°C[77°F]• •5°C[41°F],
ŒIn a system with multiple outdoor units, the defrost cycle of all units will end simultaneously.
Model
200 model
250 model
300 model
350 model
(4) Problems during defrost operation
ŒIf a problem is detected during defrost operation, the operation will be stopped, and the defrost prohibition time based on the
integrated compressor operation time will be set to 20 minutes.
(5) Change in the number of operating indoor units during defrost operation
ŒEven when there is a change in the number of operating indoor units during defrost operation, the operation will continue, and
an adjustment will be made after the completion of the defrost operation.
ŒDefrost operation will be continued, even if the indoor units stop or under the Thermo-OFF conditions until it has run its course.

-11- Refrigerant Recovery Control

Recovery of refrigerant is performed during heating operation to prevent the refrigerant from accumulating inside the unit while
it is stopped (unit in fan mode), or inside the indoor unit that is in cooling mode or in heating mode with thermo off. It is also
performed during cooling operation to prevent an excessive amount of refrigerant from accumulating in the outdoor heat ex-
changer.
It is also performed during cooling operation to prevent an excessive amount of refrigerant from accumulating in the outdoor
heat exchanger.
(1) During heating operation
Starting refrigerant recovery mode
The refrigerant recovery mode in heating starts when all of the following three conditions are met:
Œ15 minutes have passed since the completion of previous refrigerant recovery.
ŒTH4 > 115°C [239°F]
ŒFrequencies below 50 Hz
Refrigerant recovery
1) Refrigerant is recovered with the LEV on the applicable indoor unit (unit under stopping mode, fan mode, cooling, heating with
thermo off) being opened for 30 seconds.
2) Periodic capacity control of the outdoor units and periodic LEV control of the indoor units will be suspended during refrigerant
recovery operation; they will be performed after the recovery has been completed.
(2) During cooling operation
Starting refrigerant recovery mode
The refrigerant recovery mode starts when all the following conditions are met:
HWE10010
=25°C[77°F]+TH7)
SW3 - 4 OFF
10°C[50°F]
10°C[50°F]
10°C[50°F]
10°C[50°F]
Opening of LEV during refrigerant recovery
Opening of indoor unit LEV: 400 pulses
Initial opening of LEV
TH3
SW3 - 4 ON
5°C[41°F]
5°C[41°F]
5°C[41°F]
5°C[41°F]
30 seconds
Start
Finish
- 99 -
goes outside the ranges below.
GB