Midea WQP8-9339L-US Operating manual

Contents
Technical Service Manual
Dishwasher
Specification 2
Test program 23-27
Theory of parts 4-22
Function Description 3
Inspection 28-32
Location 4
PCB 5-6
Inlet valve 7-9
Drain pump 10-11
Heater 12-13
Washing pump 14-15
Procedure 24
Error code 25-27
Water circuit 3
Pressure switch 16
NTC 17-18
Flowmeter 19-20
Safety Hose 21-22
Troubleshooting 33-37
SAFETY NOTICE
This documentation is only intended for qualified technicians
who are aware of the respective safety regulations.
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Specifications
For the basic operation instructions, please refer to the
instruction manual attached with each unit.
Electrical supply 120-120V, 60Hz
Supply water pressure 0.04MPa-1.0MPa
Supply water temperature below 60℃
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Models: WQP8-9339L-US

Water circuit scheme
Water Circuit Function Description->
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Location Theory of parts->
Inlet valve
Washing pump
Capacity Overflow switch
Filter system
Heater
Over Heat Proof
Micro-switch
Dispenser
Sump
Water inlet
Pressure switch(83/63)
(only for models whose water filling
be controlled by pressure switch)
Pressure switch(140/120)
Please Note: Exploded view and part list of each model have some different visions, so
please refer to newest vision Midea sent you.
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PCB Theory of parts->
Printed Circuit Board is the control center of dishwasher, which receive and process signal
from components, send order to components and deal with the feedback information, etc.
Removing the control panel
The control panel can be removed from dishwasher door.
1. Remove the six screws securing the control panel to the door.
2. The control panel will drop down and be free of the door. But, the wiring will
still connected to the control panel.
S
08
1
2
on
Off
Access PCB
3. Disconnect the connector form PCB.
4. Remove the screws securing the PCB to control panel.
5. Remove the PCB.
6. Reverse the above procedure to install.
PCB
Note: For the majority of models, the PCB is located behind the control panel. The minority
of models locate the PCB on the side of strengthening muscle. You can judge the location by
the newest exploded view Midea sent you.
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PCB Theory of parts->
Map of PCB
Description
Mark Function
HEAT Output for Heating Element
ACL Input of live wire
ACN Input of bull line
IS Input of Door Switch
EV1-L Firewire input of inlet valve
RE Thermister
ML Washing Pump
PS Drain Pump
D/ED Dispenser
EV1 Inlet valve
EV2 Softener
EV3 Halfload Valve
ISS Salt detect
ISB Rinse detect
IAQS Overflow detect
FM Flowmeter
FAN Fan
PO Pressure Switch(83/63)
Note: This map is only applies to 9338 model.
There is small pole’s location difference
between different models.
But the marks on PCB have the same meaning
.described on the left side
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Technical data
Location of inlet valve Appearance
Inlet Valve Theory of parts->
The work principle
The inlet valve is electromagnetic valve that decide whether water enter or not. Valves are
normally closed. Each time the appliance requires water, the controller will convey an
electric signal to the coils to open the valves.
The inlet valve consist of electric coil, valve body, valve pole, filter etc.
In a word, the electromagnetic valve can act to allow water enter into machine, when it
receive the order given by controller.
to air breaker
connect to
inlet water hose
terminals
electric coil inside
The defeat point
1. The valve coil is broken, so the valve can’t open. It will cause the E1 error.
2. The filter is jammed, so water can’t enter. It will cause the E1 error.
3. The connector is loose, so the valve can’t open. It will cause the E1 error.
4. The valve pole is rusted or locked by dreg, so the valve can’t open or close. It will cause
the E1 or E4 error.
Nominal voltage 110-120VAC
Frequency 60Hz
Resistance Approx:1.0－2.2kΩ
100%ED T25
3min/5min T60
Flux 4L/min ±15％
Power 5W
Work Pressure 0.04－1MPa
Work duty
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Inlet Valve Theory of parts->
4. Left side panel
1. Baseboard
2. Left baseboard
5. Middle rear
crosspiece
Inlet valve
Access inlet valve
1. Disconnect power.
2. Remove the water inlet hose. (Note : Be careful of remain water drop.)
3. Remove the baseboard, left baseboard, left side panel and middle rear crosspiece.
4. Disconnect the 2 terminal lugs
from the inlet valve.
5. Push the valve from the lower
rear crosspiece to take it off.
6. Remove the clamp and
disconnect the inlet hose (to air
breaker) from the water valve.
7. Reverse the above procedure
to install.
1.Open the control panel and take out the PCB;
2.Unplug the CON3 and P4 wires , then use the multi-
meter Ω shelf to measure resistance between the blue
wire (EV1) and white wire (IS), the normal resistance is
about 1.0KΩ to 2.4KΩ.
3. I f the measured resistance is not correct, it means the
valve coil is broken or the connector is loose. In this
case, we should check the connection first. If the
problem hasn’t been solved by re-connection, we should
replace the valve..
4.If the resistance is OK, we need to inspect the valve
body.
Inspect inlet valve
unplug
IS
Ev1
Check electric part
Attention: Build in models have no Baseboard and
left and right baseboard, but adjustable baseboard.
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Inlet Valve Theory of parts->
Check machine part
1. If the electric part is OK, we need to check the machine part.
2. Remove the baseboard, left baseboard, top panel, left side panel and middle rear
crosspiece.
3. Check the valve filter. if the valve filter is blocked, we need clear the residues.
4. If the valve filter is clear and the valve can’t inlet water, check whether valve can act or
not. If it isn’t , we need replace the valve.
5. If the water is continue entering, we need replace the valve.
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Drain Pump Theory of parts->
Bottom View
Location of Drain Pump
Technical data
The work principle
to washing pump
connect to drain hose
motor
terminals
Drain pump integrated into sump
The work principle
Drain pump consists of electrical motor, impeller, inlet and outlet.
Drain pump is a kind of pump driven by permanent magnet synchronous motor. The rotor is
made with permanent magnet material, the running inertia of rotor is very small, the stator
consist of silicon steel stack and coil. When the drain pump is on power, the rotor will be
very easy to start.
The defeat point
1. The motor coil is broken, so the drain pump can’t work. It will cause the E2 , E4 or E1 error
.
2. The magnetism of motor rotor is weak, so drain pump cannot work. It will cause the E2, E4
or E1 error .
3. The connector is loose, so the drain pump can’t work. It will cause the E2, E4 or E1 error .
4. The rotor is locked by residues, so the drain can’t work . It will cause the E2, E4 or E1
error .
5.The drain pump assembly rack is loose, it will cause noise.
6.The non-return valve is bad, the remain water is too much.
Explanatory notes: failure of drain pump may cause E1, because
Nominal voltage 110-120VAC
Frequency 60Hz
Resistance 78－110Ω
Delivery height 0.8M
Delivery performance ≥13l/min(230VAC)
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