Carrier 69NT40-561-201, Руководство по эксплуатации и обслуживанию, Страница: 94 / 117

6 − 13 T-364
6. VALVE REMOVAL: The preferred method of remov-
ing the valve is to cut the connection between the
brazed section and the valve, using a small tube cut-
ter. Remove valve.
Alternately, use a wet rag to keep valve cool. Heat in-
let and outlet connections to valve body and remove
valve.
7. Clean the valve stem with mild cleaner, if necessary.
b. Installing the Economizer Expansion Valve:
1. The economizer expansion valve should be
wrapped in a soaked cloth for brazing.
2. Braze inlet connection to inlet line.
3. Braze outlet connection to outlet line.
4. Reinstall the cushion clamps on inlet and outlet
lines.
c. Replace filter drier, (Refer to Section 6.12).
d. Evacuate to 500 microns by placing vacuum pump on
liquid line and suction service valve.
e. Check economizer expansion valve superheat (see
Section 2.2).
6.19 DIGITAL UNLOADER VALVE
a. Removing the DUV:
1. Pump down the compressor (refer to paragraph
6.4) and frontseat both suction and discharge
valves. In the event the DUV is stuck open and com-
pressor cannot pump down, remove charge.
CAUTION
The scroll compressor achieves low suc-
tion pressure very quickly. Do not use the
compressor to evacuate the system below
0 psig. Never operate the compressor with
the suction or discharge service valves
closed (frontseated). Internal damage will
result from operating the compressor in a
deep vacuum.
2. Turn unit power off and remove power from the unit.
3. Loosen bolt on top of the DUV and remove coil
assembly.
NOTE
There is a small spacer tube between the top of
the valve and the 12 VDC coil that needs to be re-
installed into the solenoid valve coil. When re-
moving 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 clamps holding the DUV to the discharge
line.
5. Loosen the nuts attaching the DUV to the top of the
compressor.
6. VALVE REMOVAL: The preferred method of re-
moving the solenoid valve is to cut the connection
between the brazed section and the valve, using a
small tube cutter. Remove valve. (See
Figure 6 − 12).
Alternately, use a wet rag to keep valve cool. Heat
outlet connection to valve body and remove valve.
1
2
3
4
5 6
1. Sleeve
2. O − ring (hidden)
3. Screen Valve
Strainer
4. Tube
5. Solenoid Valve
Body
6. Hex Nut, 1/2 OD
Figure 6 − 12 View of Digital Unloader Valve (DUV)
Assembly
7. Examine 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 connec-
tion.
b. Installing the DUV:
1. Lubricate the gland shoulder area and o − ring with
refrigerant oil.
2. Fit new valve in position and hand − tighten the
o − ring nut.
3. Use a wet rag to keep valve cool while brazing.
Braze DUV to service valve connection.
4. Reinstall and tighten the brackets that secure the
valve body to the discharge line.
5. Torque o − ring face seal connections to 18 to 20 ft −
lbs.
6. Install the coil onto the valve body and tighten the at-
tachment 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 low side of unit as applic-
able. Refer to paragraph 6.6.1.
8. Open service valves.