NOJA Power

Technical Article

Published 09/2019

Is your Outdoor Switchgear an Arc Flash Risk?

Arc Flash Test without Arc Fault Venting
Arc Flash Test without Arc Fault Venting

Arc faults in medium voltage electrical equipment can be devastating. One of the most feared hazards of the electrical industry, a failure of electrical equipment causing an arc causes astronomical releases of energy, with temperatures exceeding 35,000 degrees.

If this arc occurs in a device or location with no dedicated pressure release, the equipment becomes a bomb, rupturing under the massive energy and spraying molten metal and shrapnel in the vicinity.

The only way to prevent catastrophic arc fault’s from causing an explosion is to design equipment to safely vent the pressure. This design should be type tested and compliant to standards ensuring public safety.

For electricity distribution equipment such as pole mounted reclosers, the priority becomes even higher. No longer is the risk of explosion contained within the substation, but the risk occurs in the city, out in suburbia and the countryside. If your pole mounted equipment is not arc fault vented, the consequences of an explosion can be disastrous.

Fortunately, modern technology designs of switchgear make arc fault vented designed pole mounted equipment an accessible technology for electricity distribution network providers and private industry.

The NOJA Power OSM Recloser is the worlds only solid dielectric insulated recloser with type tested arc fault venting.

“Every medium voltage switchgear product NOJA Power has ever designed has considered the importance of arc fault containment and venting and has been type tested to meet the requirements of arc fault containment and venting Standards,” reports NOJA Power Group Managing Director Neil O’Sullivan. “In my view this applies to all medium voltage switchgear, whether the 3 poles are enclosed a single metal tank or whether each individual pole utilises outdoor epoxy in all cases there is potential for both phase-to-phase and phase-to-ground insulation system failures and an IAC rating is essential for safety."
NOJA Power’s Patented Arc Fault design prevents catastrophic arc fault energy from reaching operators
NOJA Power’s Patented Arc Fault design prevents catastrophic arc fault energy from reaching operators

If an arc fault occurred on distribution switchgear resulting in loss of property or life, it would be challenging to justify the choice not to select arc fault venting when investments are essentially equal.”

“The arc fault standards are regularly being reviewed and updated to reflect the changes occurring in the industry, particularly as these standards are directly related to safety,” reports David Dart, the chair of the arc fault venting standards committee IEC62271-214 and NOJA Power’s Director of Research and Development. “It is important to utilise the benefits of the standards through type testing to ensure the products delivered to the consumer meet the industry standards in safety and reliability.”

NOJA Power are dedicated to making the safest, most reliable switchgear to modernise the electricity distribution grid. The OSM Recloser is the benchmark for safety in outdoor medium voltage distribution switchgear.

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