Digital Unloader Valve (Duv); Removing The Duv; Installing The Duv; Figure 7.17 View Of Digital Unloader Valve (Duv) Assembly - Carrier PrimeLINE 69NT40-561-200 Operation And Service Manual

7.24 DIGITAL UNLOADER VALVE (DUV)

7.24.1

Removing the DUV

1. Pump down the compressor (refer to
event the DUV is stuck open and compressor cannot pump down, remove charge.
The scroll compressor achieves low suction pressure very quickly. Do not use the compressor
to evacuate the system below 0 psig. Never operate the compressor with the suction or dis-
charge service valves closed (frontseated). Internal damage will result from operating the com-
pressor in a deep vacuum.
2. Turn unit power off and remove power from the unit.
3. Loosen the bolt on top of the DUV and remove the coil assembly.
There is a small spacer tube between the top of the valve and the 12 VDC coil that needs to be rein-
stalled into the solenoid valve coil. When removing the coil, it may fall out when lifted from the valve
body. Take care that the spacer is not lost; the valve will not function correctly without it.
4. Remove the clamps holding the DUV to the discharge line.
5. Loosen the nuts attaching the DUV to the top of the compressor.
6. Remove the valve. The preferred method of removing the solenoid valve is to cut the connection between
the brazed section and the valve, using a small tube cutter. Remove valve. (See
Alternatively, use a wet rag to keep valve cool. Heat outlet connection to valve body and remove valve.
O-ring (hidden)
Sleeve
7. Examine the compressor and service valves. Ensure that the o-ring is not stuck in the gland of the valve.
8. Discard the o-ring on the o-ring face seal connection.
7.24.2

Installing the DUV

1. Lubricate the gland shoulder area and o-ring with refrigerant oil.
2. Fit the new valve in position and hand-tighten the o-ring nut.
3. Use a wet rag to keep the valve cool while brazing. Braze the DUV to service valve connection.
4. Reinstall and tighten the brackets that secure the valve body to the discharge line.
5. Torque the o-ring face seal connections to 18 to 20 ft-lbs.
6. Install the coil onto the valve body and tighten the attachment bolt.
Confirm that the small spacer tube is inserted into the coil prior to attaching it to the valve body. The
valve will not function correctly without it.
7. Leak check and evacuate the low side of unit as applicable. Refer to
8. Open the service valves.
Section
!

Figure 7.17 View of Digital Unloader Valve (DUV) Assembly

Screen Valve Strainer
Hex Nut, 1/2 OD
7.4) and frontseat both suction and discharge valves. In the
CAUTION
NOTE
Tube
NOTE
Section
7–27
Figure 7.17).
Solenoid Valve Body
7.6.1.
T-362