Checking System Tightness (Vacuum Pumping) With RHS 850

The following must be observed when performing the tightness check: Firstly, the national regulations In the particular country must be followed. Secondly, the following procedure must be followed.

Vacuum-pump system for approx. 50 minutes.

The main purpose of vacuum-pumping is to evacuate any moisture present in the system. The second purpose is to ensure that no leakage is present. When vacuum pumping has been completed and the system is completely tight, fill the system with the correct quantity of refrigerant.

Carry out a final check using leak detector 951 1207.


Caution: Check compressor oil level and top up as required before vacuum-pumping A/C system.





Set selector switch (2) to EVACUATION. Ensure that cocks (7) and (8) are closed and that HP connection (9) is sealed with brass cap to prevent entry of air into unit.

Continue vacuum-pumping for at least 50 minutes.
Vacuum will now be at least 0.7-1,0 bar (10.2-14.5 psi) as indicated on outer scale of gauge (16). Vacuum pumping must continue for at least 50 minutes to ensure that all moisture is extracted.

Press VACUUM CHECK pushbutton (6) and allow to remain depressed for 4 minutes.
Vacuum gauge indication (16) may fall by only 0.01-0.03 bar (0.15-0.43 psi) during this period

Press VACUUM CHECK pushbutton (6) again to release button and extinguish lamp. Reset selector switch (2) to TEST.