Charging And Commissioning - Emerson ZX User Manual

Note that the following procedure is based upon achieving an actual system vacuum standard and
it is NOT TIME DEPENDENT!
Step-by-Step :
•
Check Suction Capability of the Vacuum Pump with a Gauge before commencing
Evacuation Process. The Vacuum Pump must be rated to achieve at least 300 microns
vacuum levels.
•
Connect the Vacuum Gauge to the system. We have included a convenient point for this
on the ZX unit (See Fig.16).
•
It is recommended to carry out a Three Time Evacuation Process as detailed as follows :
•
Start the Vacuum Pump and then open the main valve. It is assumed that the items
mentioned in Section 10.1 are still energized and the compressor cannot start
Note : Ensure that the Vacuum Pump Cannot be Switched Off during the
Evacuation Process – otherwise the pump may lose its lubrication oil to the system
and contaminate it. Therefore the pump must have a Vacuum Breaker fitted to it.
• st
1 Time Vacuum : Bring system down to 1500 microns and then Break Vacuum to 2 psig
with the same refrigerant.
• nd
2 Time Vacuum : Same as the 1
rd
•
3 Time Vacuum : Leave the pump running while checking the vacuum regularly. The
target system vacuum is 500 microns.
•
Once the target vacuum level is reached , the quality of the vacuum within the system
must be tested. This is achieved by shutting off the main pump valve, allowing the internal
system pressure to rise and recording the time taken for the vacuum to rise by no more
than 300 microns within 30 minutes. (ie; to 100 microns.)
• This process is only complete once the vacuum quality is achieved. Then close the two
manifold valves tightly. Close the pump main valve, switch off and remove the vacuum
pump.
Proceed to the step 10.4
10.4

Charging and Commissioning

st
Time Vacuum
30