In many communications and computer installations separate earth systems are often specified for three reasons - noise,security and local regulations can determine that separate earth systems are to be employed.

It is not uncommon for separate earths for lightning, mains power, computer (quiet earth) and communications to be installed.

ILSE's Transient Earth Clamp (TEC) prevents earth potential differences by operating only under transient conditions to effectively clamp all connected earths together.

Under normal condition the TEC presents an effective open circuit, once the earth potential difference exceeds the breakdown voltage of the TEC, conduction immediately occurs and the earth potentials are equalised. The TEC is a self-restoring device and has a life of over ten thousand operations.Equipotential Bonding Transient Earth Clamp

ILSE Transient Earth Clamp: ILSE TEC100
Technical Data
Application: Prevents earth potential differences
Ordering Code: TEC100
Rated DC Sparkover Voltage (100V/s): 350V
Tolerance: +/-20%
Impulse sparkover voltage (1kV/μs): 1000V
Arc Voltage: >80V
Insulation Resistance (at 100 Vdc) >1G Ohms
Capacitance @ 1MHz: 10pF
AC discharge current (50Hz; 1s; 5 times): 100A
Rated Impulse discharge current (8/20μs): 100kA
Max. Discharge current (8/20μs; 1 time): 150kA
Max. Discharge current (10/350μs; 1 time): 60kA
Dimensions: 175mm (L) x 25mm (D) Cable Leeds: 300mm on each end