Anti-Freezing Running; Control Of Compressor; Control Of Four-Way Valve; Control Of Water Pump - Gree HLR35SM/NaA-M Service Manual

MODULAR MINI CHILLER
If the control function of auxiliary e-heater is switched on in the display board, it can be
controlled automatically according to the inflow water temperature. It is necessary to set an
interval to restart the e-heater.
When the temperature detected by inflow water temperature sensor is ≤T1, the second
group of auxiliary e-heaters will work.
When the inflow water temperature is ≥T2, the second group of auxiliary e-heaters will
stop.
When the inflow water temperature is between the above two temperature, the second
group of auxiliary e-heaters remain the original state.
When the temperature detected by inflow water temperature sensor is ≤T1+tr0, the first
group of auxiliary e-heaters will work.
When the inflow water temperature is ≥T2+tr1, the first group of auxiliary e-heaters will
stop.
When the inflow water temperature is between the above two temperature, the first group
of auxiliary e-heaters remain the original state.
After startup of the unit, the auxiliary e-heater will work after all the compressor runs for a
certain period and all the above condition is reached.
2.2.4 Stop of the Unit (subject to the stop of the compressor)
Stop the unit manually or via timer: the compressor, the auxiliary e-heater and the fan
stops in sequence. After certain setting time, the four-way valve will be de-energized and the
water pump will stop.
Stop the unit upon reaching the temperature spots: the compressor stops and then the fan
stops. The four-way valve will remain the original state and the water pump will not stop.
Disorderly closedown: the compressor stops and then the fan stops (unless the fan is
wrong). After the corresponding compressor stops for a period. The water pump will not stop
while the four-way valve will remain the original state.

2.3 Anti-freezing Running

Under the stop state of any mode (except manual defrosting mode), the automatic
anti-freezing function can be switched on via the display board. The defaulted setting of this
function is OFF.
For all the modules that reach automatic anti-freezing running condition, the compressor
will run according to the setting condition and the regulation of "run for 6min and stop for 4
min".

2.4 Control of Compressor

All compressors run according to the principle of "first start, first stop; first stop, first start".
For other information, refer to the control section of 1.3.1 and1.3.2.

2.5 Control of Four-way Valve

In cooling mode, the four-way valve is off. In heating mode, the four-way valve will run after
the corresponding compressor runs. In defrosting mode, the four-way valve will be off. When
eliminating the defrosting function, the four-way valve runs. When stop the unit, the four-way
valve will stop after the corresponding compressor stops.

2.6 Control of Water Pump

When any of the modules needs to be started up, all the water pumps will run. When one
module stops upon reaching certain temperature spots, all the water pumps remain running.
When one module is stopped manually or via timer or due to malfunction, the water pump of
this module remains running. Only when all the modules are stopped manually or via timer, the
water pump will stop 5 min after all the compressor stops.
CONTROL
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