Connecting The Manifold Gauge Set; Removing The Manifold Gauge Set; Figure 7.3 Service Valve - Carrier Transicold 69NT40-561-001 Operation And Service Manual

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 pressure.
Then, the valve is opened 1/4 to 1/2 turn to measure the pressure.
1) Line Connection
2) Access Valve
3) Stem Cap
4) Valve stem
Connection of the manifold gauge/hose set (see
the compressor is being serviced, the high side coupling is connected to the discharge service 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.).
7.3.1

Connecting the Manifold Gauge Set

1. Remove service valve stem cap and to make sure the valve is backseated.
2. Remove access valve cap (see
3. Connect the field service coupling (see
4. Turn the field service coupling knob clockwise, which will open the system to the gauge set.
5. To read system pressures, slightly midseat the service valve.
6. Repeat the procedure to connect the other side of the gauge set.
To prevent trapping liquid refrigerant in the manifold gauge set be sure set is brought to suc-
tion pressure before disconnecting.
7.3.2

Removing the Manifold Gauge Set:

1. While the compressor is still ON, backseat the high side service valve.
2. Midseat both hand valves on the manifold gauge set and allow the pressure in the manifold gauge set to be
drawn down to low side pressure. This returns any liquid that may be in the high side hose to the system.
3. Backseat the low side service valve. Backseat both field service couplings and frontseat both manifold hand
valves. Remove couplings from access valves.
4. Install both service valve stem caps and service port caps (finger-tight only).

Figure 7.3 Service Valve

1
6
5
Figure
Figure 7.3).
Figure
CAUTION
!
2
4
5) Compressor Or Filter Drier Inlet Connection
6) Valve (Frontseated)
7) Valve (Backseated)
- - - - -
7.4) is dependent on the component being serviced. If only
7.2) to the access valve.
7–3
3
7
T-340