News

July 2026

What Is an External Maintenance Bypass Switch and Why Do I Need One?

In today’s world, where downtime can cost businesses thousands, or even millions of dollars per hour, reliable power protection is non-negotiable. Uninterruptible Power Supplies (UPS) play a critical role in keeping servers, data centres, manufacturing equipment, and essential operations running during power disturbances. But what happens when the UPS itself needs maintenance, repair, or replacement? That’s where an External Maintenance Bypass Switch becomes essential.

What Is an External Maintenance Bypass Switch?

An External Maintenance Bypass Switch (EMBS) or Bypass Switch for short, is a specialised switchgear device installed in the power path between the mains supply, the UPS system, and the critical load. It allows operators to safely divert power directly from the utility mains to the connected equipment, completely isolating the UPS unit.

Unlike internal bypass functions built into some UPS units, an external bypass is a standalone solution, typically housed in its own enclosure or panel using quality German made Sontheimer rotary cam switches and mechanically interlocked for safe operation

At ASN Switchgear in Derrimut, Victoria, we design and manufacture high-quality bypass switches tailored to Australian standards and specific site requirements. These provide robust isolation and seamless transfer capabilities for a wide range of UPS systems.

How Does It Work?

In normal operation, power flows from the mains → UPS → critical load. When maintenance is required:

The operator manually transfers the load to the bypass mode.
The UPS is electrically isolated (input and output disconnected).
Power flows directly from the mains to the load without interruption (make-before-break).
Service technicians can then work on the UPS safely, with all internal power removed.

Once maintenance is complete, the process is reversed to bring the UPS back online.

This external approach ensures complete isolation, unlike some internal bypasses that may leave parts of the UPS energised.

Why Do You Need One? Key Benefits

Zero Downtime During Maintenance Critical facilities (data centres, hospitals, manufacturing plants, telecommunications) cannot afford to shut down operations for UPS servicing. An external bypass keeps the load powered directly from the mains while the UPS is offline.
Enhanced Safety for Technicians Full isolation removes all AC power from inside the UPS, reducing arc flash risks and allowing safe internal work, battery replacement, or full unit swap-outs.
Longer UPS Lifespan and Better Performance Regular maintenance without operational pressure means technicians can perform thorough inspections, cleaning, and component replacements, extending the life of your UPS investment.
Flexibility for Upgrades and Replacements Need to upgrade to a larger UPS or replace a faulty unit? The external bypass makes this possible without a full site shutdown.
Compliance and Risk Management Australian standards and industry best practices often recommend or require proper bypass arrangements for critical power systems. It demonstrates due diligence in business continuity planning.
Cost Savings The cost of installing a quality external bypass is minimal compared to the potential losses from unplanned downtime or emergency after-hours service calls.

When Should You Consider Installing One?

Your facility relies on continuous power for IT, industrial processes, or life-safety systems.
You have a single UPS without built-in bypass or where the internal bypass is insufficient.
You perform (or plan to perform) regular preventive maintenance.
You operate in high-reliability environments such as mining, rail, data centres, telecommunications, Government, healthcare, defence, finance & banks or 24/7 manufacturing in Melbourne, regional Victoria, or across Australia.

Why Choose ASN Switchgear?

Located in Derrimut, Victoria, ASN Switchgear is an Australian manufacturer specialising in premium UPS bypass switches, maintenance bypass panels, rotary cam switches, and custom low voltage switchgear for critical power applications.

Our solutions are:

Built to Australian standards
Customisable to your exact power requirements (single-phase, three-phase, various amperages)
Designed for reliability with proper interlocking and safety features
Supported by local expertise and service

Whether you need a wall-mounted unit, rack-integrated solution, or a full custom panel, our team can design and deliver the right external maintenance bypass switch for your setup.

Conclusion

An External Maintenance Bypass Switch is more than just an accessory, it’s a vital component of a resilient power protection strategy. It ensures your UPS can be serviced safely and efficiently while your critical operations continue uninterrupted.

Don’t wait for your next UPS service outage to highlight the need. Contact the team at ASN Switchgear today to discuss your requirements.

ASN Switchgear

4/72 Makland Drive, Derrimut VIC 3026

Phone: (03) 8390 6790 or 0417 104 698

Email: asn@asn-switchgear.com.au

www.asn-switchgear.com.au

Stay Switched On

May 2026

Critical Power Demand Driving Growth in Australia’s Data Centre Industry

Australia’s data centre industry continues to experience rapid growth as demand for cloud computing, artificial intelligence (AI), and critical digital infrastructure accelerates across the country.

Industry reports forecast significant increases in data centre capacity over the coming years, with Sydney and Melbourne remaining major hubs for hyperscale and critical infrastructure development. Growing demand for reliable power distribution and uptime is placing greater importance on high-quality critical power equipment and maintenance bypass solutions.

ASN Switchgear continues to support the Australian critical power sector through the manufacture and supply of Australian-made UPS bypass switches, maintenance bypass panels and custom switchgear solutions designed for reliable operation in mission-critical environments.

As Australia’s digital infrastructure expands, dependable power switching and isolation solutions remain essential to supporting uptime, service continuity and infrastructure resilience.

July 2022

Quality Onload Switches in stock and available for you now.