Emerson ZX, User Manual

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installation. Start the vacuum pump. The liquid line solenoid should be energized at this point,
the cabinet (evaporator) fans run and compressor crankcase heaters energized. This will
involve powering up the unit so it is important to disconnect the live feed wire to the
compressor contactor (so the compressor cannot run and the crankcase heaters can be
energized).
•
Then open both valves on the manifold then open the main vacuum valve on pump and run
the system until the vacuum level is at around 0.85 bar (as read on the manifold suction
gauge.)
•
Shut off the main vacuum pump valve. Check for vacuum rise – use the manifold compound
gauge. A rise would indicate a large leak.
•
If vacuum holds for 10 minutes, break vacuum with nitrogen and pressurize to 10 bar. Check
for leaks by feel and sound. (This step is to look for large leaks only.) Repair leakage if leak is
detected.
Proceed to step 10.2.
10.2 Leak Test (by refrigerant with nitrogen pressurization)
Step-by Step :
•
Release nitrogen from system, start vacuum pump and open main pump valve.
•
Then evacuate for a second time to 0.85 bar (as read on the manifold gauge.)
•
Break this vacuum with R22, after shutting off the main pump valve and then stopping the
pump.
•
Allow the system to equalize with R22 cylinder pressure (to at least 1.7 bar)
•
Then remove the cylinder and increase system pressure, using nitrogen to 15 bar.
•
Leak test all joints (inside and outside the unit, ie; the complete system) using (at least) a
halide leak detector or (preferably) an electronic leak detector.
•
Repeat all previous steps in this section until the system is completely leakage free.
•
Release all pressure from the system, remove the nitrogen connections and reconnect
manifold service hose to vacuum pump main valve.
Proceed to step 10.3
10.3 Evacuation
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