16. Control functions
16.1 Control type for cooling and heating
The system will adjust the temperature according to the water outlet temperature of the master module. The
wired controller will control the compressor on/off according to the difference between the water outlet
temperature and the set temperature.
In cooling mode, if the water outlet temperature is higher than the set temperature, the system will start up
one compressor. After waiting for a control cycle (can be set by factory parameter D1), if the water outlet
temperature is still higher than the set temperature, the system will continue starting up a second
compressor in cooling mode. The others will be deduced as the analogy.
If the water outlet temperature is lower than the set temperature (factory parameter B1), the system will
stop that compressor firstly. After waiting for a cycle, if the water outlet temperature is still lower, the system
will stop a second compressor. The other will be deduced as the analogy.
The heating control principle is as the same as that of cooling mode, the only difference is that it uses the
factory parameter B2.
16.2 Interval of startup/stop of the water pump and compressor, and the startup/stop of 4-way valve and fan
In standby state, the water pump will not start up. As soon as entering the running state, the water pump will
start up firstly. When changing from the running state to standby state or shutoff state, water pump will stop
automatically 30 seconds later.
The min interval is 3 minutes from stop to the next startup. And 3 minutes later, the first compressor will
startup. In order to balance the compressors running time, in the condition of 3 minutes interval, the
compressor will work in turn according to the principle: who not startup will startup earlier, who startup
earlier will stop earlier.
Compressor, 4-way valve, fan motor, etc exterior equipments will comply with the "interval of external
equipment action" (D2) to stop/startup one be one.
16.3 The temperature limitation of water outlet of cooling and heating mode
"Permitted minimum temperature of out water in cooling" (B3) and "Permitted maximum temperature of out
water in heating" (B4) are used to make the protection system work normally in the permitted condition.
16.4 Ambient temperature limitation of cooling and heating
"ambient temperature limit in cooling" (B5) and "ambient temperature limit in heating" (B6) are the limitation
parameters to protect the system normal operation.
16.5 Condition of electric heater start/stop
After the compressor startup, when the real ambient temperature is lower than the startup temperature of