16
Service Information
To achieve the required levels of evacuation, a
properly maintained two stage vacuum pump in
good condition is required. It is absolutely essential
to maintain your vacuum pump according to the
manufacturer’s instructions including required
oil changes at the recommended intervals.
Vacuum pump oil should always be changed after
evacuating a contaminated system.
Vacuum pump performance should be checked
periodically with a micron gauge.
1. Make certain that charging cylinder valve,
hand shut-off valve, and manifold gauge
valves are closed.
2. Start vacuum pump.
3. Open hand shut-off valve and slowly
open both manifold valves, turning
counterclockwise, for two full rotations.
WARNING
R-134a systems are particularly susceptible
to moisture contamination which can only
be prevented by evacuating the system for a
minimum of 30 minutes to attain a minimum
29.9 inch (500 micron or lower) vacuum.
4. Operate the vacuum pump for a minimum
of 30 minutes to a minimum of 29.9” (500
micron) vacuum.
NOTE
On products with Low side leaks you must heat
the crankcase area of the compressor though
out the 30 minutes you are running your vacuum
pump to pull a vacuum on the system. Every 4
to 5 minutes while you are running your vacuum
pump and heating the crankcase area shake
the compressor. By heating the crank- case you
are heating the oil in the compressor. This will
drive the moisture out of the oil. By shaking the
compressor this will allow the moisture to come to
the top of the oil faster so the vacuum pump can
remove the moisture from the system.
CAUTION
If high vacuum equipment is used, just
crack both manifold valves for a few minutes
and then open slowly for the two full turns
counterclockwise. This will prevent the
compressor oil from foaming and being drawn
into the vacuum pump.
Evacuating 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
• Grit cloth or Scotch-Brite
• 45% silver solder and flux
• Heat Gun
Installing Evacuation and Recharging
Equipment
1. Disconnect refrigerator from electrical supply.
2. If compressor was replaced, install correct
sized process tube adaptor 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 adaptor.
3. Install correct sized process tube adaptor 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 adaptor.
• High-side (pressure gauge) hose to high-side
process tube adaptor.
• Center port manifold hose before hand shut-
off valve to charging cylinder.
• Center port manifold hose after hand shut-off
valve to vacuum pump.
