Nanometrics Trillium Compact User Manual page 93

Appendix B - Grounding guidelines
B.4 Grounding the Sensor in a Vault or Test Lab Installation
Use the guidelines in this section to ground a Trillium Compact Vault that is installed in a vault
or in a test lab.
In a vault installation, connect the case of the digitizer to a suitable earth ground such as a
ground stake or buried screen. Connect the case ground of the seismometer and other
equipment to case ground of the digitizer via shielded cables as provided by Nanometrics. See
Figure B-3.
In a test lab or other building with mains power, connect the case of the digitizer to the safety
ground of the mains power system (typically via the case ground of an AC-DC power supply).
Connect case ground of the seismometer and all other equipment to case ground of the
digitizer via shielded cables as provided by Nanometrics.
In a dry vault or test lab installation it is possible (but not recommended) to keep the entire
instrument system isolated or with only a high-impedance connection to earth ground. The
equipment can perform well in this configuration, however this is not recommended for safety
reasons. Connecting the case ground of all equipment to earth ground will maintain a safe
ground potential on accessible parts of the equipment.
Figure B-3 - System grounding for a vault or test lab installation
16889R10 • 2020-11-12 Page 93