Refrigeration Service Operations
151
4. If the complete ETV assembly is being
replaced, unsolder and remove the valve body.
It may be necessary to unsolder the tubes
above or below the valve body to obtain
enough clearance to remove the valve body.
Note the position of the valve body so the new
one will be placed in the same position. The
new ETV could interfere with other
components if it is not placed in the same
position as the old one.
Installation of Service Kit
NOTE: Do not connect the ETV harness to main
wire harness and turn the unit on before the
stepper motor and piston assembly is installed in
the valve body. The controller is programmed to
close the ETV when the unit is turned on. If the
unit is turned on with the ETV harness
connected to main wire harness, the controller
will attempt to close the ETV. This will cause the
piston to be turned (screwed) off the threaded
shaft of the stepper motor because the valve body
is not present to stop it. Further disassembly is
required to reassemble the piston and stepper
motor. See “Reassembly of Piston and Stepper
Motor”.
1. The new stepper motor and piston assembly is
supplied with the piston in the open position.
In the open position the bottom edge of the
piston is 0.3 to 0.7 in. (8 to 18 mm) from the
bottom edge of the brass nut. The piston
retracts to open and extends to close.
1.
Small Hex on Stepper Motor
2.
Large Nut
3.
Valve Body
Figure 234: Electronic Throttling Valve
1.
Unscrew Large Nut
2.
Backup Wrench
Figure 235: Removing Electronic Throttling Valve
1
2
3
1
2
1.
Bottom Edge of Brass Nut
2.
Bottom Edge of Piston
Figure 236: Stepper Motor and Piston Assembly
with Piston in Fully Open Position
1
2
0.3 in.
(8 mm)
