3-9
Refrigeration System
Equipment Needed for Evacuation &Recharging:
• Heated charging cylinder
• Standard 3-port manifold gauge set:
- 4 charging hoses
- Tee fitting with valve core stem removed
(Robinair No. 40396)
- Hand shut-off valve (Robinair No.40380)
• Two stage vacuum pump
• Process tube adapter kit (Robinair No.12458)
• Tubing cutter
• Pinch-off tool capable of making leak proof seal
• Complete brazing torch set
• Small 3-corner file
• Gritcloth or Scotch-Brite
• 45% silver solder and flux
• Heat Gun
Installing Evacuation and RechargingEquipment
1. Disconnect freezer from electrical supply.
2. If compressor was replaced, install correct sized
process tube adapter on process tube.
If compressor was not replaced, cut process tube
with tubing cutter leaving as much tube as possible
and install correct size process tube adapter.
3. Install correct sized process tube adapter on
high-side process tube.
4. Attach refrigeration service gauge manifold to
system in following order:
• Low-side (compound gauge) hose to suction
side process tube adapter.
• High-side (pressure gauge) hose to high-side
process tube adapter.
• Center port manifold hose before hand shut-off
valve to charging cylinder.
• Center port manifold hose after hand shut-off
valve to vacuum pump.
Check the serial plate for the correct refrigerant
type. It is extremely important to verify the type
of refrigerant in the system before starting any
sealed system repairs.
With the possible exception of the vacuum pump,
all service equipment that comes in contact with
R-134a during evacuation and recharging must be
dedicated. Accordingly, R-134a will require a
dedicated charging cylinder, manifold gauge set,
process tube adapters, and hoses. Any residual
mineral oil on other tools (tubing cutter, etc.) must
be thoroughly cleaned off before using on
R-134a/Ester oil systems. It will be necessary to
check with the manufacturer of your vacuum
pump for refrigerant and oil compatibility issues.
If you use a vacuum pump with mineral oil to
evacuate an R-134a system, it is ABSOLUTELY
ESSENTIAL to have a shut-off valve between the
pump and your manifold gauge set as shown on
page 4-11. The hand valve must be closed during
all times when the vacuum pump is not operating.
This will prevent the migration of mineral oil vapor
into the R134a/Ester oil system. If the vacuum
pump should stop during evacuation for any
reason, the hand pump shut-off valve must be
closed immediately.
Insure that your refrigeration hoses are specified
for use with R-134a refrigerant. Research has
shown that compounds in standard refrigeration
hoses may enter sealed systems and ultimately
restrict the cap tube in an R-134a system.