Carrier CDII-184R1-0CTR4 Installation & Operation Manual page 53

Model
FCU Fan Motor
Quantity
Model
CDU Fan Motor
Quantity
9.6.7 EXV/EEV
The electronic expansion valve (EEV) operates with a much more sophisticated design.
EEVs control the flow of refrigerant entering a direct expansion evaporator. They do this in response
to signals sent to them by an electronic controller. A small motor is used to open and close the valve
port. The motor is called a step or stepper motor. Step motors do not rotate continuously. They are
controlled by an electronic controller and rotate a fraction of a revolution for each signal sent to them
by the electronic controller. The step motor is driven by a gear train, which positions a pin in a port in
which refrigerant flows. A cutaway of an EEV with step motor and drive assembly is shown in
reference Figure. Step motors can run at defined steps per second and can return to their exact
position very quickly. The controller remembers the number of step signals sent by the controller. This
makes it possible for the controller to return the valve to any previous position at any time. This gives
the valve very accurate control of refrigerant that flows through it.
Model
EXV Cam
EXV Motor
9.6.8 COMPRESSOR
Model
Compressor Model
number
Compressor part no
Compressor Motor
Winding resistance
Ω @ 20 ˚C
7 HP 11 HP
1026996 1026997
1 1
7 HP
1022298
2
7 HP
1021485
1021486
7 HP
TNB306FPNMT ANB52FKRMT
1029757
1.02 OHM 0.30 OHM
14 HP
1026997 + 1026994
1 + 1
11 HP 14 HP
1029818 1029818
2
11 HP 14 HP
1022536 1030873
1022537 1030874
11 HP 14 HP
ANB66FVAMT
1029758 1030715
0.23 OHM
53
22 HP
1031972 + 1031973
1 + 1
22HP
1029818
2 2
22 HP
1022536
1022537
22 HP
ANB52FKRMT+
ANB52FKRMT
1029758
0.30 OHM