HBM Genesis series Technical Note page 19

GN610, GN611 Isolation and type testing
Every one of the automatic range changes will be identified within the
measurement data. Not only will the measured input be scaled correctly with
the adapted input range, but also the exact moment the automatic range
change happens is identified within Perception software.
As the highest selectable range is ± 1 kV the ultimate protection for the system
will be to disconnect the input from the external signal source. This step will
only be executed if the system is in the ± 1 kV range and local temperature is
still outside maximum operating limits. Disconnecting from the external signal
source is done by grounding the input. When inputs are grounded, the only
connections to the external signal are the input connectors and the input pin of
the ground relay.
Thermal shutdown in critical conditions
This protective scheme allows for any overload condition the input would be
confronted with during normal operation. For any other failure condition that
would result in excessive heat dissipation, the GEN series mainframe has a last
protective stage built in. When local temperatures reach a critical condition the
system will turn-off the mains power automatically to prevent damage to the
system or other systems near the GEN series system. Maximum and critical
temperature conditions are defined as such that it is very unlikely the system
will ever reach this critical condition when operating within its specified
conditions.
HBM public 19