GREE Air-ccoled Closed Control Unit Service Manual
101
on the humidifier. Measure current for humidifying and compare it with that in touchable screen.
At the same time, observe water level of humidifier tank and status of valve on screen. In fact,
the current measured is almost the same with that displayed on screen. So there is no
malfunction of current transformer. With increase of water level inside the humidifier tank, the
current value increases. When water valve is in off status on screen, current value is 3.7. When
water level keeps increasing, the current value increases too. In that case, there is high water
level alarm and the current value is 4.3. So we can get a conclusion that high water level alarm
is caused due to small humidifying current as the humidifier tank is full of water which is
incurred by small electric conductivity of water supplied.
Conclusion:
When humidifying current is two low due to bad electric conductivity of water
supplied or long operation of the humidifier, treat the water to improve its electric
conductivity(eg, adding dissolving salt) so that the humidifier can normally operate.
Case 3
Malfunction Phenomenon:
In normal conditions, touchable screen shows warning “water on floor” and the unit can’t be
started up.
Possible causes:
（
1
）
Flooding switch is damaged;
（
2
）
Electrode is damaged;
（
3
）
Wiring is incorrect.
Possible causes:
check if the power indicator of flooding switch is on. If not, it means
there is no +12V power supplied for flooding switch. Check if the wiring of mainboard is correct.
If it is correct, replace the flooding switch. When power indicator of flooding switch is on, check
if malfunction indicator is on. If it is on, there is a malfunction. Open shell of flooding switch to
check if electrode is short-circuited or the wiring terminal is oxidized. When malfunction is
removed, the malfunction indicator will be off. Press reset button to clear the warning. If power
indicator of flooding switch is on and malfunction indicator is off, the switch is ok. Check if wire
connecting to mainboard is correct. If it is correct, replace the mainboard.
Conclusion:
when touchable screen shows warning “water on floor”, the unit will stop and
can’t be started up, which may be incurred by oxidization of electrode, short circuit, malfunction
of flooding switch or loose wiring of mainboard.
Case 4
Malfunction Phenomenon:
the mainboard of controller doesn’t work after energization
and the communication indicator doesn’t blink. Touch ON button on touchable screen, the
outdoor unit doesn’t operate.
