Processes and Functions
6
TD831077
VI - 9
9. Inter-Refrigerant System Oil Recovery Control
¶
Control is performed for recovering the oil accumulated in the indoor unit, refrigerant pipes, or other locations in the
system. (maximum of two minutes)
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Control description
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If the oil does not return to the original level even after the oil level reaches 0 and operation is performed for a set
time, the thermostat for the outdoor unit is turned off. Operation is then restarted, and this control is started if the oil
level does not rise above 1 when this operation is performed and stopped three times.
* During operation, the self-separator oil recovery control and inter-outdoor unit oil recovery control are performed
simultaneously.
¶
If the PC compressor oil level is 1 or less when the AC compressor is turned on, and the PC compressor oil level
does not reach 2 by performing self-separator oil recovery control and inter-outdoor unit oil recovery control, the AC
compressor is stopped, and the PC compressor operates at the maximum capacity. When this state continues for 30
minutes or more, inter-refrigerant system oil recovery control is started.
¶
When all connected outdoor units are operating at the maximum capacity, the indoor unit electronic expansion valve
runs at the initial pulse for the cooling cycle and 480 pulses (fully open) for the heating cycle.
¶
During inter-refrigerant system oil recovery control, self-separator oil recovery control and inter-outdoor unit oil
recovery control is performed simultaneously based on the conditions. However, the count is not cleared unless the
oil level reaches 2.
¶
After inter-refrigerant system oil recovery control, normal control is performed. However, if the oil level becomes 0
without reaching 2, operation is stopped after a set time, and a warning is issued.
10. 4-way Valve Adjustment Valve
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When the power is turned on, a warning is issued, or at least one hour has passed in a fully stopped state, control is
performed for unifying the 4-way valve modes of all the outdoor units and for recovering refrigerant accumulated in
the pipes.
* Cooling operation
: • All of the outdoor units operate at the maximum capacity for one minute.
• The opening and closing of the indoor unit electronic expansion valve is the initial pulse
regardless of the unit operation/stopping.
* Heating operation
: • All of the outdoor units operate at the maximum capacity for 1 to 10 minutes. When this
control is started, only the outdoor unit that must operate runs at the maximum capacity in
response to the indoor unit capacity request. However, this operation is not performed
when the power is turned on and after a warning is issued.
• This control is performed for a minimum of one minute, and it ends when the maximum
condensation temperature is 35
°
C or above.
11. Refrigerant Movement Control
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Refrigerant passes through the balance pipes and is recovered from the stopped unit when shortage of refrigerant is
occurred during operation. However, priority is given to the various types of oil control.
* During cooling operation
: Operation unit : The recovery valve is turned on.
Stop unit
: The bypass valve and balance valve are turned on.
* During heating operation
: Operation unit : The recovery valve is turned on.
Stop unit
: The balance valve is turned on, and the outdoor fan operates at
the maximum speed.