Http://Splitoff.ru/Tehn-Doc.html - Daikin VRV System R-22 PLUS Series Manual

Si33-102.book Page 30 Tuesday, June 26, 2001 3:18 PM
Installation
Choosing a General
Vacuum Pump
Refrigerant piping content volume of the Plus Series is larger than the VRV Inverter Series, and
consequently takes more time for vacuum drying. If you have time to spare, you may use the same vacuum
pump, but if you want to save time, you will have to use a pump with higher exhaust velocity (exhaust
volume).
1. Vacuum pump performance
The 2 most import things for determining vacuum pump performance are as follows:
(1) Exhaust velocity
(2) Degree of vacuum
(1) Exhaust velocity
Exhaust volume is usually expressed as l/min or m³/h. The larger the number, the faster vacuum id
achieved.
Generally speaking, the faster the exhaust velocity, the larger and heavier the vacuum pump itself is.
Commercially available vacuum pumps (exhaust velocity of 20 - 30 l/min) usually take an extremely
long time to achieve vacuum. (We recommend a vacuum pump of approx. 60 - 100 l/min.)
(2) Degree of vacuum
Ultimate vacuum varies largely according to use of the vacuum pump. Vacuum pumps used for vacuum
forming cannot be used for vacuum drying. (A vacuum pump with a high degree of vacuum is required.)
When selecting a vacuum, you should select one which is capable of achieving 0.2 Torr of ultimate
vacuum.
Degree of vacuum is expressed in Torr, micron, nnHg, and Pascal (Pa). The units correlate as follows:
Gauge Pressure
Absolute Pressure
Torr
Micron
cmHg
Pa
Degree of vacuum must be within the range expressed by
0 Torr
0 Pa
76 cmHg
Perfect vacuum
30
Unit Standard atmospheric pressure
kg/cm²
kg/cm² abs 1.033
Torr 760
Micron 760000
cmHg
hPa 1013.33
5 Torr
667 Pa
75.5 cmHg
Vacuum target value

: http://splitoff.ru/tehn-doc.html

SiE33-102
Perfect vacuum
0 –1.033
0
0
0
0 76
0
760 Torr
1013.33 hPa
0 cmHg
Standard atmospheric pressure
General Information
(V0992)