– 60 –
B
A
Magnet
Male screw
Female screw
Needle valve
Body
Fluid direction
Upper Coils
Lower Coils
Electronic Expansion Valve (EEV)
The EEV is installed between the dryer outlet and the evaporator inlet. (See Component Locator Views.)
The EEV meters the ow 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 ow. 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.
(Continued Next Page)
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 ow
rate.
COM
A
A
Upper coil
COM
B
B
Lower coil
Each coil contains a CW winding and a CCW
winding:
• A and B are CW.
• A and B are CCW.
— —
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
#3 Red
#4 Black
#5 Gray
#2 Yellow
#1 Orange
#3 Red
#4 Black
#5 Gray
#2 Yellow
Control Board J603
To Next Page
Loading...
Need help?
General
