Kaisai KMK-60RY1, Service Manual

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26 202004
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6 Special Control
6.1 Oil Return Operation
In order to prevent the compressor from running out of oil, the oil return operation is conducted to recover oil that has
flowed out of the compressor and into the refrigerant piping.
The oil return operation starts when the following condition occurs:

When the compressor cumulative operating time reaches 6 hours.
The oil return operation ceases when any one of the following three conditions occurs:

Oil return operation duration reaches 5 minutes.

Compressor stops.
Tables 3-6.1 show component control during oil return operation in cooling mode.
Component
Wiring diagram
label
6-16kW Control functions and states
Inverter compressor COMP
●
Runs at oil return operation rotation speed
DC fan motor FAN
●
Controlled according to cooling mode
Electronic expansion valve EXV
●
304 (steps)
Four-way valve 4-WAY
●
Off
Tables 3-6.2 show component control during oil return operation in heating and DHW modes.
Component
Wiring diagram
label
6-16kW
Control functions and states
Inverter compressor COMP
●
Runs at oil return operation rotation speed
DC fan motor FAN
●
Controlled according to heating mode
Electronic expansion valve EXV
●
304 (steps)
Four-way valve 4-WAY
●
On
6.2 Defrosting Operation
In order to recover heating capacity, the defrosting operation is conducted when the outdoor unit air side heat exchanger
is performing as a condenser. The defrosting operation is controlled according to outdoor ambient temperature, air side
heat exchanger refrigerant outlet temperature and the compressor running time.
Table 3-6.3: Component control during defrosting operation
Component
Wiring diagram
label
6-16kW
Control functions and states
Inverter compressor COMP
●
Runs at defrosting operation rotation speed
DC fan motor FAN
●
Off
Electronic expansion valve EXV
●
480 (steps)
Four-way valve 4-WAY
●
Off
6.3 Force Cooling Operation
The force cooling operation helps the refrigerant recovering before removal the water side heat exchanger.
The force cool mode can be ended by pushing the button on the outdoor refrigerant system main PCB named “FORCE” for
5s or this mode will be ended automatic if the system has operated force cool mode for more than 30 minutes.
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Table 3-6.4: Component control during force cool operation
Component
Wiring diagram
label
6-16kW Control functions and states
Inverter compressor
COMP
●
Runs at force cooling operation rotation speed
DC fan motor FAN
●
Runs at force cooling operation speed
Electronic expansion valve EXV
●
304 (steps)
Four-way valve 4-WAY
●
Off
6.4 Fast DHW Operation
Fast DHW operation is used to quickly meet a requirement for domestic hot water when DHW priority has been set on the
user interface.
Domestic hot water demand priority can be ended by changing the switch on controller from "on" to "off".
Table 3-6.5: Component control during fast DHW operation
Component
Wiring
diagram label
6kW 8/10/12/14/16kW
Control functions and states
Inverter compressor
COMP
● ●
Controlled according to load requirement
DC fan motor FAN
● ●
Controlled according to outdoor heat exchanger
pipe temperature
Electronic expansion valve EXV
● ●
Position (steps) from 0 (fully closed) to 480 (fully
open), controlled according to discharge superheat
Four-way valve ST
● ●
On
Tank electric heater TBH
● ●
On
6.5 Two zones control
1
Two zones control function is used to control temperature of each zone separately, thus different type radiator will operate
at its optimal temperature and water pump cycle time will be reduced to save energy.

Cooling mode
In two zones control for cooling mode, when the setting temperature of a certain zones is reached, the zone and water
pump of this zone will turn off.

Heating mode
In two zones control for heating mode, the on/off control of zone and water pump is same with cooling mode, but in
addition, the mixing valve (3-way valve SV3) control function will be activated to adjust the water temperature of the low
temperature zone by control the opening time and closing time of the valve. The mixing valve will only turn on when two
zones control for heating is activated. On other conditions, the mixing valve will keep off. When the valve initially turns on,
the opening time and closing time is same and then the time is controlled according to the difference between water pipe
temperature and setting water temperature of the controlling zone.

Hydraulic adapter PCB (Optional)
With the help of hydraulic adapter PCB, totally 8 thermostats can be used at the same time for maximum 8 rooms to
control heat pump.
Note:
1.
U
nits just have the controlling function, while the mixing valve, water pump of each zone need to be field
supplied and connect to unit.
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