PACD011001G2 / PACD011004G3
Installation 1
Urban Multi Inverter “MX1” Series
51
Vacuum Drying
Procedure
There are two vacuum drying methods and the appropriate one should always be chosen to conform with
individual local conditions.
[Normal vacuum drying]........The standard method
[Operational steps]
1. Vacuum drying (1st time): Connect a manifold gauge to the service port of the liquid or gas pipe and
operate the vacuum pump for at least 2 hours.
(The degree of vacuum produced should be in excess of 5 mmHg)
If after 2 hours the vacuum produced has not exceeded 5 mmHg then either there is moisture in the
pipe or there is a leak. Operate the vacuum pump for a further hour.
If, even after 3 hours, the vacuum has not reached 5 mmHg then check the system for a leak.
2. Carry out maintained vacuum test.
Produce a vacuum in excess of –755 mmHg and do not release it for an hour or more. Check the
vacuum gauge to make sure that it has not risen. (If the gauge does rise then there is still moisture in
the pipe or there is a leak somewhere.)
3. Additional charge of refrigerant.
Connect the charging cylinder to the liquid pipe service port and charge with the required amount of
refrigerant.
4. Open stop valve to the full.
Open the stop valves on the liquid and the gas pipes to the full.
Note:
Vacuums should be produced in both the liquid and the gas pipes.
(Because there are a large number of functional components in the indoor unit which cut off the vacuum
mid–way through)