High Energy Testing of varistors
Our High Energy Test Laboratory (HETL) assures protection engineers worldwide.
HETL is rated up to 2,000 Volts, 8,000 Amps and 2 Megajoules.
HETL is unique – no other varistor manufacturer can offer Metrosil’s standard of high energy testing. From concept to design, HETL illustrates our commitment to innovation and reliability.
One-of-a-Kind High Energy Test Laboratory
HETL was commissioned for two reasons. Firstly, relying on off-site laboratories to test our varistor disc assemblies was proving impractical due to large production volumes. Secondly, even the best test laboratories in the world could not offer the testing accuracy that we required.
To handle thousands of Metrosils per year, we required a facility that could subject varistor assemblies to their rated currents and energies with a high degree of precision. Therefore, we introduced HETL in 2016, which is rated up to 2,000 Volts, 8,000 Amps and 2 Megajoules. With a choice of test waveforms (square, voltage controlled; square, current controlled; and inductive discharge) we are able to offer 100% testing of Metrosil varistor discs in-house.
HETL is the last stage of our manufacturing process. After mixing silicon carbide with a ceramic binder we press the resulting mix into discs. These discs are then sintered and metal-sprayed before being tested and assembled as varistors. Once assembled, each varistor is high energy tested by HETL. HETL administers maximum voltage, current and energy values through every single assembly. A test certificate is produced upon completion, containing key statistics to assure OEMs and end users that their assets will be fully protected.
Another key benefit of HETL is that it enables our technical team to carry out a wide range of controlled tests on Metrosil products, no matter their stage of development or production. This means that our customers can be confident that their valuable assets will always be protected.
In summary, HETL offers the following:
- Extreme high energy testing capabilities
- All Metrosil assemblies are tested to maximum voltage, current and energy before installation
- Enables OEMs to realise the benefits of using silicon carbide varistors within their excitation systems as per IEEE 421.6 and DLT 843-2010