6--1
T-334
SECTION 6
SERVICE
NOTE
To avoid damage to the earth’s ozone layer, use a refrigerant recovery system whenever removing refriger-
ant. When working with refrigerants you must comply with all local government environmental laws. In the
U.S.A., refer to EPA section 608.
WARNING
Never use air or gases containing oxygen
for leak testing or operating refrigerant
compressors. Pressurized mixtures of air
or gases containing oxygen can lead to ex-
plosion.
6.1 SECTION LAYOUT
Service procedures are provided herein beginning with
refrigeration system service, then refrigeration system
component
service,
electrical
system
service,
temperature recorder service and general service. The
refrigeration section divided into standard unit (with
service valves) and semi-hermetic systems (equipped
with service fittings). Refer to the Table of Contents to
locate specific topics.
6.2 MANIFOLD GAUGE SET
The manifold gauge set (see Figure 6--1) is used to
determine system operating pressure, add refrigerant
charge, and to equalize or evacuate the system.
1
2
3
4
5
6
7
1. Opened (Backseated) Hand Valve
2. Suction Pressure Gauge
3. Discharge Pressure Gauge
4. Closed (Frontseated) Hand Valve
5. Connection to high side of system
6. Connection to either:
a. Refrigerant cylinder OR
b. Oil Container
7. Connection to low side of system
Figure 6--1 Manifold Gauge Set
When the suction pressure hand valve is frontseated
(turned all the way in), the suction (low) pressure can be
checked. When the discharge pressure hand valve is
frontseated, the discharge (high) pressure can be
checked. When both valves are open (all the way out),
high pressure vapor will flow into the low side. When the
suction pressure valve is open and the discharge
pressure valve shut, the system can be charged. Oil can
also be added to the system.
A R-134a manifold gauge/hose set with self-sealing
hoses (see Figure 6--2) is required for service of the
models covered within this manual. The manifold
gauge/hose set is available from Carrier Transicold.
(Carrier Transicold part number 07-00294-00, which
includes items 1 through 6, Figure 6--2.) To perform
service using the manifold gage/hose set, do the
following:
a. Preparing Manifold Gauge/Hose Set For Use
If the manifold gauge/hose set is new or was
exposed to the atmosphere, it will need to be eva-
cuated to remove contaminants and air as follows:
1. Back seat (turn counterclockwise) both field service
couplings (see Figure 6--2) and midseat both hand
valves.
2. Connect the yellow hose to a vacuum pump and re-
frigerant 134a cylinder.
To High Side
Access Valve
1
5
2
5
6
8
4
To Low Side
Access Valve
3
3
7
1. Manifold Gauge Set
2. RED Refrigeration and/or Evacuation Hose
(SAE J2196/R-134a)
3. Hose Fitting (0.5-16 Acme)
4. YELLOW Refrigeration and/or Evacuation Hose
(SAE J2196/R-134a)
5. Hose Fitting w/O-ring (M14 x 1.5)
6. High Side Field Service Coupling (Red Knob)
7. BLUE Refrigeration and/or Evacuation Hose
(SAE J2196/R-134a)
8. Low Side Field Service Coupling (Blue Knob)
Figure 6--2 R-134a Manifold Gauge/Hose Set
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