Protection Function - Haier HSU24VHG(DB)-G&W Service Manual

5.2.3 The control of the outdoor electronic expansion valve
When starting the compressor: the opening size of the valve must be guaranteed to have entered into
the standard opening size, and then the compressor can be started.
When refrigeration is in vain (the machine is shut down or is in the state of retrograde operation), the
opening size of the expansion valve of the indoor unit is 5 steps;
When heating is in vain, the opening size of the expansion valve of the indoor unit is 55 steps;
When the outdoor unit is shut down, the valve is opened completely for 2 minutes, and then begin
initialization.
The scope of refrigerationg valve
The scope of heating valve
The valves are adjusted according to the degree of superheat
5.2.4 Four way control
For the details of defrosting four-way valve control, see the defrosting process.
Four way working in other ways:
Under the mode of heating, open the four-way valve, when the compressor is not started or changed
to non-heating mode, make sure the compressor is stoped for 2 minutes, and then close the four-way
valve.

5.2.5 Protection function

5.2.5.1 TTC high temperature-preventing protection
Once the machine is started, it can run TTC overheating protection of air-blowing, but air-blowing
sensor malfunction must alarm after 4 minutes during which the compressor is started (during the
course of self-detection, there's no such limitation)
Sensor detection methods: 100 times (one cycle of procedure run is one time, and about 5ms,
detection method for each time: continuously sampling for 8 times, then order them and take the
mean value of the middle 2 values), take the mean value.
TTC
°F
361
329
323
307
297
TTC≥ °F
361
indoor, others don't last.
Abnormal stop
Decreasing the frequency rapidly 1HZ/second
Decreasing the frequency slowly (1HZ/10seconds)
The frequency doesn't change.
Increasing the frequency (1HZ/10second)
Increasing the frequency 1HZ/1second
lasts for 20 seconds. Overheating protection of air-blowing, alarm malfunction to the
90-----480 steps
80-----480 steps
24
Functions and Control
SHa SHa.
Domestic Air Conditioner