Electronic Expansion Valve (Eev) - GE GEH50DEED Technical Service Manual

Electronic Expansion Valve (EEV)

The EEV is installed between the dryer outlet and the evaporator inlet. (See
The EEV meters the flow of liquid refrigerant entering the evaporator at a rate that matches the amount of
refrigerant being boiled off in the evaporator (gas). The valve is designed to maintain proper superheat. (See
.)
Refrigeration System
The EEV is a stepper motor expansion valve. in operation, the magnet-needle valve assembly is rotated by
the stepper motor and by means of a screw structure that has linear motion, opening and closing to regulate
refrigerant flow. Upper and lower coils inside the EEV operate off 12-VDC pulses supplied by the control. The
pulses occur too quickly to be measured with a voltmeter.
Magnet
Upper Coils
Lower Coils
Upper coil
A
COM
A
Each coil has a resistance value of 46 W ±3 W. Gray wire is common. Check resistance of each coil; gray to
black, gray to red, gray to yellow, and gray to orange.
#1 Orange
#2 Yellow
#3 Red
#4 Black
#5 Gray
Male screw
Female screw
Needle valve
Body
B
Fluid direction
A
Lower coil
B
COM
B
Control Board J603
– 60 –
Component Locator Views
Valve Construction and Operation
• Energized coils rotate the magnet.
• A precise gearing arrangement with a
male/female screw set attached to the
rotating magnet drives the valve needle in
a linear motion.
• The opening degree of the valve is
determined by this linear motion of the
valve needle against the valve seat.
• This action controls the refrigerant flow
rate.
Each coil contains a CW winding and a CCW
winding:
• A and B are CW.
— —
• A and B are CCW.
End of EEV Wire Harness
.)
#1 Orange
#2 Yellow
#3 Red
#4 Black
#5 Gray
(Continued Next page)