Carrier PrimeLINE - Valve Override Controls

T-362 7–32
3. Loosen the bolt on top of the DUV and remove the coil assembly.
NOTE
There is a small spacer tube between the top of the valve and the 12 VDC coil that needs to be
reinstalled 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 Figure 7.17).
Alternatively, use a wet rag to keep valve cool. Heat outlet connection to valve body and remove valve.
Figure 7.17 View of Digital Unloader Valve (DUV) Assembly
1) Screen Valve Strainer
2) Tube
3) Solenoid Valve Body
4) Hex Nut, 1/2 OD
5) Sleeve
6) O-ring (hidden)
- - - - -
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.
NOTE
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. See Section 7.6.1.
8. Open the service valves.
7.25 Valve Override Controls
Controller function code Cd41 is a configurable code that allows timed operation of the automatic valves for
troubleshooting. Test sequences are provided in Table 7–1. Capacity mode (CAP) allows alignment of the
economizer solenoid valve in the standard and economized operating configurations. DUV Capacity Modulation%
Setting (PCnt) and Electronic Expansion Valve (EEV) allows opening of the digital unloader valve and electronic
expansion valve, respectively, to various percentages. If the unit is equipped with an LIV, the Liquid Valve Setting
allows the LIV to be automatically controlled, or manually opened and closed.
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