NSG 438
18
4.2.5.
Interlock
The NSG 438 has an integrated interlock system in keeping with standard
practice for high voltage test equipment.
This system has the following functions:
Inputs:
1.
Input for external monitoring purposes of, for example, special
coupling networks and access control.
2.
Internal emergency off button opens the interlock.
Outputs:
1.
Operating mode: the NSG 438 can generate no high voltage as
long as the interlock is not closed. High voltage generation is
prevented if the interlock is opened during a test procedure.
2.
Warning lamps: when the interlock is closed the green lamp is
switched off and the red lamp is illuminated.
3.
Interlock output for other system devices.
The interlock system is common to all Schaffner instruments and hence
several devices can be connected together.
The instrument is equipped with two 15-way connectors for interlock input
and output. The interlock loop must always be correctly terminated at both
ends. In achieving this, the interlock wiring must connect all the safety
contacts together.
When using original Schaffner accessories this is achieved automatically
by using 15-way standard cables wired 1:1 to link the interlock connectors.
An arbitrary number of instruments or accessories can be incorporated in
this safety concept.
The high voltage supply can only be activated if the safety requirements in
all the associated devices are fulfilled (emergency off buttons released,
safety contacts closed).
