Installing R--134A Manifold Gauge/Hose Set - Carrier AC310 Operation And Service Instructions Manual

CAUTION
The AC310 & AC350 Rooftop Systems have
R134a service port couplings installed on
the compressor and 1/4 inch flare (Acme)
fittings installed on the unit piping.
5.4.1 Installing R- -134a Manifold Gauge/Hose SET
An R--134a manifold gauge/hose set with self--sealing
hoses is pictured in Figure 5--1. The manifold
gauge/hose set is available from Carrier Transicold.
(Carrier Transicold P/N 07--00294--00, which includes
items 1 through 6, Figure 5--1). To perform service using
the manifold gauge/hose set, do the following:
a. Preparing Manifold Gauge/Hose Set for use.
1. If the manifold gauge/hose set is new or was ex-
posed to the atmosphere it will need to be evacuated
to remove contaminants and air as follows:
2. Back--seat (turn counterclockwise) both field service
couplers (see Figure 5--1) and mid--seat both hand
valves.
3. Connect the yellow hose to a vacuum pump and an
R--134a cylinder.
4. Evacuate to 10 inches of vacuum and then charge
with R134a to slightly positive pressure of 1.0 psig.
5. Front--seat both manifold gauge set hand valves and
disconnect from cylinder. The gauge set is now
ready for use.
T-304
SUCTION
PRESSURE
GAUGE
OPENED
(Backseated )
HAND VALVE
To Low Side
Access Valve
3.
BLUE
2.
4.
6.
To Refrigerant Tank
or Vacuum Pump
Blue Knob
Figure 5- -1 Manifold Gauge Set (R- -134a)
1. Manifold Gauge Set
2.. Hose Fitting (0.5-16 Acme)
3.. Refrigeration and/or Evacuation Hose
. (SAE J2196/R-134a)
4.. Hose Fitting w/O-ring (M14 x 1.5)
5.. High Side Field Service Coupling
6.. Low Side Field Service Coupling
b. Connecting the Manifold Gauge Gauge/Hose Set.
To connect the manifold gauge/hose set for reading
pressures, do the following:
1. Connect the field service couplers (see Figure 5--1)
to the high and low in--line service ports.
2. Turn the field service coupling knobs clockwise,
which will open the system to the gauge set.
3. Read the system pressures.
c. Removing the Manifold Gauge Set.
1. While the compressor is still ON, mid--seat 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.
To prevent trapping liquid refrigerant in the
manifold gauge set be sure set is brought to
suction pressure before disconnecting.
2. Back--seat both field service couplers and front--seat
both manifold set hand valves. Remove the couplers
from the in--line access valves.
3. Install both in--line access valve caps.
5--2
DISCHARGE
1.
PRESSURE
GAUGE
CLOSED
(Frontseated)
HAND VALVE
2.
To High Side
Access Valve
3.
RED
3.
YELLOW
4.
5.
Red Knob
CAUTION
04/08