INFICON VSC150A absolute switch, passiv - Manual (Page 17)

2.5.2 In a Vacuum System it must be Prevented
that in Case of Failure Gas Flows into the
Vacuum Chamber
Assembly as shown in the diagram, Fig. 7.
Also in this case, as in 2.5.1, the contact setting of the
Vacuum Switch should correspond to the basic adjust-
ment. Control the electrically operated valve (normally
closed) via the break-contact, terminals 12 and 13 (see
Fig. 5), of the SV switching amplifier. In case of power
failure this valve closes. When the power returns the
valve is not opened before the pressure in the sensing
volume and the reference volume of the Vacuum Switch
has become equal.
2.5.3 Automatic Venting of a Vacuum Chamber
End of venting at a minimum pressure of 20 mbar below
atmospheric pressure, max. at atmospheric pressure.
Assembly as in Fig. 8.
The venting valve (normally closed) is controlled via the
make-contact of the switching amplifier relay, terminals
11 and 12 (see Fig. 5). For venting up to atmospheric
pressure the basic adjustment of the Vacuum Switch
contact applies. If venting should end before, the swit-
ching pressure can be continuously lowered by 20 mbar
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tina42e1 (2005-03) VSC150.ga
tina42e1 (2005-03) VSC150.ga
2.5.2 In a Vacuum System it must be Prevented
that in Case of Failure Gas Flows into the
Vacuum Chamber
Assembly as shown in the diagram, Fig. 7.
Also in this case, as in 2.5.1, the contact setting of the
Vacuum Switch should correspond to the basic adjust-
ment. Control the electrically operated valve (normally
closed) via the break-contact, terminals 12 and 13 (see
Fig. 5), of the SV switching amplifier. In case of power
failure this valve closes. When the power returns the
valve is not opened before the pressure in the sensing
volume and the reference volume of the Vacuum Switch
has become equal.
2.5.3 Automatic Venting of a Vacuum Chamber
End of venting at a minimum pressure of 20 mbar below
atmospheric pressure, max. at atmospheric pressure.
Assembly as in Fig. 8.
The venting valve (normally closed) is controlled via the
make-contact of the switching amplifier relay, terminals
11 and 12 (see Fig. 5). For venting up to atmospheric
pressure the basic adjustment of the Vacuum Switch
contact applies. If venting should end before, the swit-
ching pressure can be continuously lowered by 20 mbar
SV
VSC 150
M
R
Fig. 7 Differential pressure monitoring of a valve
M
SV
VSC 150
R
Fig. 8 Automatic venting between -20 mbar and
atmospheric pressure
SV
VSC 150
M
R
Fig. 7 Differential pressure monitoring of a valve
M
SV
VSC 150
R
Fig. 8 Automatic venting between -20 mbar and
atmospheric pressure