Operation
24
4.3
Security Mechanisms
The safety circuit of the system permanently tests all security-related parameters and
switching operations on the system as soon as an operating mode is selected that
activates the HV output. Should the safety circuit detect a deviation from the monitored
conditions while in high voltage mode, high voltage is immediately switched off and the
HV output is discharged. The fault that occurred is shown in the display and must be
eliminated before operation can be resumed.
The following conditions must be fulfilled in order to perform tests under high voltage:
•
The HV “interlock” key switch
must be in the position.
•
The EMERGENCY OFF switch
must not be pressed.
•
F-Ohm: The transfer resistance between protective earth and operational earth
must not exceed a certain threshold (possible fault sources: missing protective
earth connection, poor earthing conditions or HV plugs that are not securely
bolted).
•
The HV connection cable must be correctly connected (see below).
If activated in system settings (see page 25), an automatic connection check takes
place upon activation of the test and prelocation operating modes. In order to get the
mode started, the check must result in reasonable resistance values between the
individual connections.
In the case of any deviations, the wiring diagram corresponding to the selected
operating mode is displayed. The following figure shows the screen view after a failed
connection check:
In this case, the system should be turned off and the connections should be checked
and corrected.
If the check keeps failing even after the connections have been verified and
corrected, this may be due to the characteristics of the cable under test (e.g. very
high capacity, low resistance cable faults or small cross section). In such a case,
the function should be turned off in the system settings (see page 25).
Introduction
The safety circuit’s
conditions
Check of connections
Check of Connections:
Cancel
2 - black
3 - red/brown
5 - blue
