Carrier 69NT40-541-505, Руководство по эксплуатации и обслуживанию, Страница: 94 / 143

T-368 7–2
Figure 7.2 R-134a Manifold Gauge/Hose Set
1. RED Refrigeration and/or Evacuation Hose (SAE
J2196/R-134a)
2. Hose Fitting (0.5-16 Acme)
3. YELLOW Refrigeration and/or Evacuation Hose
(SAE J2196/R-134a)
4. Hose Fitting with O-ring (M14 x 1.5)
5. High Side Field Service Coupling (Red Knob)
6. BLUE Refrigeration and/or Evacuation Hose (SAE
J2196/R-134a)
7. Low Side Field Service Coupling (Blue Knob)
- - - - -
7.3 SERVICE VALVES
Compressor suction, compressor discharge, and liquid
line service valves (see
Figure 7.3 ) are provided with a
double seat and a gauge connection, which enables
servicing of the compressor and refrigerant lines.
Turning the valve stem clockwise (all the way forward)
will frontseat the valve to close off the suction, dis-
charge or liquid line and open the gauge port to the
compressor or low side. Turning the stem counter-
clockwise (all the way out) will backseat the valve to
open the connections and close off the port.
With the valve stem midway between frontseat and
backseat, both of the service valve connections are
open to the access valve path.
For example, the valve stem is first fully backseated
when connecting a manifold gauge to measure pres-
sure. Then, the valve is opened 1/4 to 1/2
− turn to mea-
sure the pressure.
Figure 7.3 Service Valve
1. Line Connection
2. Access Valve
3. Stem Cap
4. Valve stem
5. Compressor or Filter Drier Inlet Connection
6. Valve (Frontseated)
7. Valve (Backseated)
- - - - -
Connection of the manifold gauge/hose set (see Fig-
ure 7.4 ) is dependent on the component being ser-
viced. If only the compressor is being serviced, the
high side coupling is connected to the discharge ser-
vice valve.
For service of the low side (after pump down), the high
side coupling is connected to the liquid line service
valve. The center hose connection is brought to the
tool being used (vacuum, tank, etc.).
Connecting the manifold gauge set:
a. Remove service valve stem cap and make sure
the valve is backseated.
b. Remove service port cap (See Figure 7.3 ).
c. Connect the high side field service coupling (see
Figure 7.2 ) to the discharge or liquid line valve
service valve port.
d. Turn the high side field service coupling knob
(red) clockwise, which will open the high side of
the system to the gauge set.
e. Connect the low side field service coupling to
the suction service valve port.
f. Turn the low side field service coupling knob
(blue) clockwise, which will open the low side of
the system to the gauge set.
g. To read system pressures, slightly midseat the
high side and suction service valves.
CAUTION
!
To prevent trapping liquid refrigerant in
the manifold gauge set, be sure set is
brought to suction pressure before dis-
connecting.
To Low Side
Access Valve To High Side
Access Valve
1
2
3
2
4
5
6
4
7
1
2
3
4
5
6
7
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