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Note: First and the largest capacity indoor unit
should always be connected to circuit A as primary.
4. If the manifold gauge set’s hoses have 1/4” SAE
connections, a 1/4” to 5/16” SAE port adapter will
be needed. (Sold Separately).
5. Connect the center hose of the gauge manifold
(usually yellow) to the vacuum pump.
6. Fully open the Low side valve on the low pressure
side of your gauge manifold. Assure that the High
side valve on the high pressure side of your gauge
manifold stays closed.
7. Start the vacuum pump and operate according to
pump manufacturer’s specifications. If your vacuum
pump has a valve, open it as well.
8. Perform vacuuming / evacuation for a minimum
period of 30 minutes and check that the low pressure
gauge indicates a vacuum of 30 in/hg (500 microns).
(A more sensitive vacuum gauge should be used if
available).
9. If the proper vacuum cannot be achieved within
30 minutes, the vacuum pump should be kept
running for an additional 15 minutes. If after the
additional 15 minutes of operation, the vacuum still
cannot be achieved, there could be a leak at one or
more of the flare pipe connections at either end of
a refrigerant pipes. Leak must be located and the
leaking nut must be tightened properly before
re-vacuuming the circuit.
10. If the vacuum is achieved, close the low side
valve at the low pressure side on your gauge manifold
first and shut the vacuum pump off. Leave the gauge
manifold set and the hoses connected and recheck
the vacuum reading 15 minutes later to assure there
is no vacuum loss. (Very small increase in vacuum level
is normal).
11. Circuit A is now dry and free of contaminants. Do
not remove the hose of your gauge manifold set from
the service port.
12. Remove the 2-way (Liquid) Common (Master) Valve’s
brass dust cap. Insert proper size Allen wrench into the
valve core and turn it until it is back seated. Do not force
it once it stops turning.
Cap
Valve body
Valve stem
Flare nut
2-way (Liquid) Valve
of the Common (or the
master) service valve
13. Remove the 3-way (Gas) Common (Master) Valve’s
brass dust cap. Insert proper size Allen wrench into the
valve core and turn it until it is back seated. Do not
force it once it stops turning.
Flare nut
Cap
Valve body
Valve stem
3-way (Gas) Valve of the
Common (or master
Service Valve)
14. Remove the 2-way (Liquid) Valve’s brass dust cap
of circuit A. Insert proper size Allen wrench into the
valve core and turn it counter clockwise for 1 turn,
wait for 3 seconds and quickly close the valve by
turning it in reverse direction. Check your low pressure
gauge on the manifold to assure it now indicates
positive pressure of approximately 80 to 120 PSI in
your lines.
Cap
Valve body
Valve stem
Flare nut
2-way (Liquid) Valve
of the a circuit
15. Apply soap-water mixture on both the indoor unit
connections and the outdoor unit connections for
circuit A with a soft brush to check for leakage at the
connecting points of the piping. If you notice air
bubbles, the specific connector has leakage and must
be tightened to stop the leakage.
(An electronic leak detector will be more efficient to
use for this if available).
16. Re-insert proper size Allen wrench into the valve
core of the Liquid Valve (2 way) valve for circuit A and
turn it counter clockwise until it is fully back seated.
Do not force it, once it stops turning. Repeat the leak
checking procedure entirely at all connections of
circuit A. If you find a new leak, close the 2-way (Liquid)
valve you just opened first and tighten the flare nut
at the leaking connection until the leak is sealed.
Reopen the 2-way (Liquid) valve and check again.
17. Remove the 3-way (Gas) Valve’s dust cap for
circuit A. Insert proper size Allen wrench into the
valve core and turn it counter clockwise until it is
fully back seated. Do not force it, once it stops turning.
