Medium-voltage distribution networks operate in some of Australia’s most demanding environments. Lightning, switching events, bushfire risk, heat, moisture, pollution and remote operating conditions can all place additional demands on network equipment.
For energy network operators and electrical engineers, selecting the right medium-voltage surge arrestors, load break switches and other switchgear components is therefore about more than equipment ratings. Solutions need to provide dependable protection and switching performance while aligning with applicable Australian and international standards and the practical requirements of local network environments.
Insulect provides a range of surge arrestors and load break switches designed for Australian distribution applications, supported by local technical expertise, engineering and project services.
Overvoltage transients can result from lightning strikes and switching operations, potentially placing distribution equipment and connected assets under significant electrical stress.
Insulect’s Class A surge arrestors are designed for primary protection of high-voltage equipment in overhead distribution and substation networks. They are intended for demanding applications including critical infrastructure, rural feeders and exposed overhead lines, where protection against high-energy overvoltage events is particularly important.
The Class A range is designed to meet IEC 60099-4 and is available across voltage ratings from 3 kV to 64 kV, with 5 kA and 10 kA discharge current ratings. The arrestors are also certified to AS 1307.2-1996 (R2015) for zero spark production, supporting applications where ignition risk is an important consideration.
Australian distribution infrastructure can be exposed to harsh environmental conditions, including high UV exposure, moisture, pollution and bushfire-prone areas.
Insulect’s Class A surge arrestors use HTV silicone rubber housings with fibreglass cores. The housing is designed to provide weather and pollution resistance, while the compact, lightweight construction supports installation in a range of applications.
The arrestors are suitable for indoor, outdoor and high-risk bushfire environments and are designed to withstand high-stress overvoltage conditions associated with Rapid Earth Fault Current Limiter (REFCL) networks.
For distribution applications where a spark-free design is required, these characteristics can help network operators address both equipment protection and site safety considerations.
Surge protection is only one part of a reliable medium-voltage network. Operators also need dependable equipment for isolating circuits, sectionalising feeders and switching loads during routine operations, maintenance and network events.
Insulect’s range of load break switches is designed for medium-voltage distribution applications, with configurations suited to different network layouts and operating requirements.
Air Break Switches (ABS), for example, provide visible isolation and switching for overhead applications. The range is designed and tested in accordance with AS 62271.102 / IEC 62271.102 and includes side-break and vertical-break configurations, with pole-top and mid-pole mounting options.
Visible isolation can provide operators with clear confirmation of circuit status during switching and maintenance activities. The switches can also be supplied with or without load-break functionality, depending on the application.
Network configurations and operating requirements vary considerably across Australia. Equipment may need to be installed on distribution poles, within substations or in constrained locations, while operating requirements may range from manual field switching to remote SCADA control.
Insulect’s air break switches can be configured for different mounting arrangements, including vertical, underhung and pole-top installations. Blade types, contact configurations and actuation methods can also be tailored to specific installation requirements.
For applications requiring load-break operation, the range includes integrated load-break capability up to 36 kV and 630 A. The switches are also available in different voltage and current configurations, including ratings up to 72.5 kV and current ratings from 630 A to 1250 A for applicable designs.
Manual and motorised operating options can also support SCADA integration and future network automation.
For networks requiring load switching in demanding outdoor environments, Insulect also offers gas-insulated load break switch solutions.
The Gas Load Break Switch range is designed for medium-voltage overhead distribution and rail applications, with ratings from 12 kV to 36 kV. Options include manual or remote operation, integrated protection and custom enclosures to suit network requirements.
For applications where eliminating SF₆ is a priority, Insulect’s Epoxy Insulated Load Break Switch provides an alternative based on solid epoxy insulation and vacuum interruption technology. The design eliminates the need for SF₆ gas while providing high dielectric strength and dependable switching performance.
The SF₆-free switch is designed for 12 kV and 24 kV systems with up to 630 A breaking current. It can be operated manually or fitted with a remotely controlled actuator for SCADA and automated distribution applications.
Its sealed construction and maintenance-free design are intended to support long-term operation in demanding outdoor environments, while the product can be installed at feeder lines, sectionalising points and connection points for renewable generation or industrial loads.
For Australian energy network operators, compliance with relevant standards is an important consideration when specifying power distribution equipment.
Insulect’s Class A surge arrestors are specified against AS 1307.2-1996 (R2015), IEC 60099-4 and ANSI/IEEE C62.11, while applicable air break switch designs are designed and tested to IEC 62271.102 / AS 62271.102.
The Epoxy Insulated Load Break Switch is tested in accordance with IEC 62271-103, with a 12 kV / 24 kV voltage rating and up to 630 A rated current.
Standards alignment is an important part of equipment selection, but the appropriate specification still depends on the network, installation environment, operating requirements and applicable project standards.
Surge arrestors and load break switches perform different but complementary roles within distribution networks.
Medium-voltage surge arrestors help protect equipment from transient overvoltages, including lightning and switching-related events. Load break switches provide controlled switching, isolation and sectionalising capability, helping operators manage network configuration and maintenance activities.
When these switchgear components are correctly selected and integrated, they can contribute to a more robust medium-voltage network protection strategy.
For Australian distribution environments, considerations can include:
A technically appropriate solution needs to account for the complete operating environment rather than focusing on a single equipment specification.
Selecting suitable surge arrestors and load break switches is only part of a successful network project. Equipment configuration, procurement, installation, testing and commissioning can also influence project outcomes.
Insulect provides local technical support and engineering services for high-voltage switchgear solutions. Its services include engineering design, procurement and logistics, testing and commissioning, turnkey project delivery and factory visits for inspection and factory acceptance testing.
This local support enables network operators and electrical engineers to work with a team that understands the practical requirements of Australian projects while coordinating with established equipment partners and manufacturing facilities.
Australia’s distribution networks continue to evolve, with increasing requirements for network reliability, renewable generation connections, automation and resilient infrastructure.
Selecting the right medium-voltage surge arrestors and load break switches can help address the protection, switching and operational requirements of modern distribution networks.
Insulect’s range provides options for overhead distribution, substations, renewable connections, industrial applications and demanding environmental conditions, with configurations available to suit different voltage, current, mounting and operating requirements.
For energy network operators and electrical engineers, the key is to select equipment based on the specific electrical, environmental and operational requirements of each application, and to ensure the selected power distribution equipment aligns with applicable Australian and international standards.
Insulect supports Australian energy network operators and electrical engineers with surge arrestors, load break switches and other medium-voltage switchgear components, backed by local engineering and technical support.
Contact Insulect to discuss the right solution for your medium-voltage distribution network.