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7. Outdoor units Operation
7.1. Temperature parameters
¾
Outdoor ambient sensor temperature (T
out_amb.
)
¾
Outdoor heat exchanger tube sensor temperature (T
out_tube
)
¾
Setting temperature (T
set
)
7.2. System basic function
7.2.1 Cool mode
7.2.1.1 Heat mode transfers to Cool mode
(1) Compressor stops.
(2) Four-way valve delayed 2mins power off.
7.2.1.2 Cool operation and stop running condition
(1) When T
in_amb
- T
set
≥
0.5°C, cooling operation will run (Cool mode starts up and arrive at the temperature of unit on).
(2) When the capacity requirement is 0 (Cool and unit stops).
Note
: Unit off, fan is the same as Cool and unit will stop.
7.2.1.3 Outdoor fan motor control
Outdoor fan unit start up (stop-turn on), firstly run at high speed for 3 mins, then according to control logic adjust, when
compressor stop, outdoor fan will stop after 1min delay.
(1) To turn on one indoor unit: when T
out_amb
<25°C, outdoor fan will run at low fan speed.
When T
out_amb
≥
25°C, outdoor unit will run at high speed.
(2) To turn on two indoor units: when T
out_amb
<18°C, outdoor fan will run at low speed; when T
out_amb
≥
18°C, outdoor fan
run at high speed.
Note:
When only one unit is turned on, to increase turn on one indoor unit dual unit, outdoor fan will run at high speed for
3min, then according to control logic adjust.
7.2.1.4 Four-way valve control
In this mode, four-way valve off (cannot electrify)
7.2.1.5 Control logic in detail
According to the difference of indoor unit evaporator inlet and outlet temperature (called “actual overheat degree”) and
goal overheat degree to confirm indoor unit expansion valve open degree.
7.2.1.6 Anti-freezing protection under Cool mode
If satisfied with the anti-freezing protection condition, system will enter into anti-freezing protection status, if only single
unit anti-freezing protection act, the indoor unit capacity preset as 0; if all the unit start anti-freezing protection, the
compressor will stop, outdoor fan will stop after 60s delay. If arrive at anti-freeze condition, finish anti-freezing.
7.2.2 Dehumidifying mode
Under this mode, outdoor fan, compressor start up is the same with control condition and Cool modes.
7.2.3 Heat mode
7.2.3.1 Cool mode transfers to Heat mode
(1) Compressor stops running.
(2) Four-way valve delays 2mins will electrified; same disposal procedure under each protection.
7.2.3.2 Heat operation and stop running condition
(1) When T
in_amb
≤
(T
set
+3) ± 0.5°C, heating operation will run (Heat mode starts up and arrive at the temperature of unit
on).
(2) In Heat mode unit will stop
7.2.3.3 Fan motor control
Outdoor unit start up (Stop --Turn on) firstly will run at high speed for 3 mins, it will accord to control logic to adjust, if
compressor stop running, outdoor fan will stop after 1 min delay. Outdoor fan control logic: There will be at least 80s for
each modes switch.
7.2.3.4 Four-way valve control
