Example Of Repair - Haier SYJS-0308 Service Manual

Refrigerant leaks
Discharging air temperature heat sensitive resistor is improper
Electronic expansion valve or 2-way valve is closed
Treatment: check if there is leakage part, test system pressure in rated operation state to
determine if there is leakage? Check the state of electronic expansion valve and 2-way valve.
Test and measure the numerical value of discharging air temperature heat sensitive resister.

7.3 Example of repair

(1) Phenomenon: after changing the PC board of outdoor unit, do not reset. After powering on
and turning on unit, some of the indoor units can operate normally, the other indoor units
display " communication trouble with outdoor unit"
Treatment: switch the unit number lock switch of outdoor unit to unlocked state, after
powering on, outdoor unit will examine indoor units and automatically enter indoor units' unit
number. After about 5 minutes, switch this switch to lock state. Restart indoor units, the
trouble is solved.
(2) Phenomenon: indoor unit displays DC current protection
Treatment: check if power module is penetrated, after changing PC board, power on to restart
unit, compressor operates several minutes then stops. The DC current protection still appears.
Check the compressor driving circuit of, find the compressor down-lead is short circuit
because of high temperature. After changing the compressor down lead, the trouble is solved.
(3) Phenomenon: after finishing installation of indoor unit, start unit to operate, find B system
can operate normally, A system compressor does not work.
Treatment: when left factory, the indoor unit EEPROM was default set as joint in B system.
After finishing installation, when set indoor unit number, because the unit number lock switch
is always in unit number locked state, the outdoor unit will not examine indoor units. So the
indoor units connected with A system can not change their default setting, their signals sent to
outdoor unit are overlapped with the signals sent by indoor units of B system, which cause
only B system works. After resetting indoor unit number complied with procedure, the trouble
is solved.
(4) Phenomenon: when cooling, make A system work solely, find A system do not work, but B
system work.
Treatment: after checking, find communication wire and pipe are wrongly connected. After
connecting the wire correctly, reset unit number, the trouble is solved.
(5) Phenomenon: start 3 sets of indoor units in the same system, under the condition of
compressor current and discharging air temperature are not too high, the operation
frequency is low. After compressor operates, some indoor units " operation" indicators still
do not light.
Treatment: it is because when setting the unit number of each indoor unit, the time interval is
too short, which causes the unit numbers are set repeatedly. After resetting the indoor unit
number, the trouble is solved.