Pfeiffer Vacuum A 1204H, Operating Instructions Manual

Page: 35 / 92

Advanced settings
35
7 Advanced settings
This chapter describes the available functions and their respective operating modes to
help the user configure the parameters according to the operating specifications during
processes.
7.1 Nitrogen injection device
The nitrogen injection device is used to facilitate the evacuation of pollutants produced
by the process, to dilute harmful gases in the compression stages and to protect the me-
chanical parts of the pump.
7.1.1 Management modes
The management mode is selected when the pump is stopped:
– from HHR [DEFINITION] [PURGE CMD] (see 8.2) ,
– from serial link (see Serial link Operating instruction s).
DISABLED The purge operated automatically.
The stand-by (4) and purge (3) valves open/close when the pump is started/stopped.
When the pump stops, purging is extended by a time T (see 7.1.3) .
ENABLED
The
stand-by (4)
and
purge (3)
valves open/close simultaneously following a
PURGE
command independent of the pump being started/stopped:
– from HHR by pressing PURGE button (see 4.3) ,
– from remode control (see 8.3) .
To activate this mode, the coding wheel
S1
must be in position
1
.
Fig. 9: Nitrogen injection device
1 Pressure regulator Nitrogen flow adjustement
2 Mass flowmeter Nitrogen flow reading
3 Purge valve Nitrogen flow check
4 Stand-by valve
5 Injection manifold fitted with check valves and calibrated
injectors Nitrogen flow distribution in each stage
6 Exhaust pressure sensor Exhaust pressure check
BF Functional block
BF
3
4 1
2
5
6
Time
T
1
0
Purge valve
Stand-by valve
Pump
START STOP