Testing and commissioning services

Circuit Breaker Testing Services Australia

Request a quote Capability statement (PDF)

Talk to an engineer: 1300 730 499 or service@megavar.com.au

Last reviewed: July 2026 by Matt Geoghegan, CEO, Megavar

Megavar tests high voltage and medium voltage circuit breakers across Australia, at commissioning and through service life, to confirm they will open and close correctly and interrupt fault current within their rated time. Testing covers timing analysis, contact and dynamic resistance, insulation, and gas or vacuum integrity, with every result captured in a clear diagnostic report. Because Megavar also commissions the switchgear and protection around the breaker, circuit breaker testing fits into a single tested and energised outcome rather than a standalone check.

ISO 9001, 14001 and 45001 certifiedLicensed in every Australian stateTeams in Hobart, Launceston, Adelaide and Newcastle

Megavar engineer testing an HV circuit breaker with a CIBANO 500

What is circuit breaker testing?

Circuit breaker testing is the measurement and verification of a circuit breaker's mechanical and electrical performance to confirm it operates within its design limits. It checks how fast the breaker opens and closes, whether the poles operate together, the resistance across the main contacts, the condition of the insulation, and the integrity of the SF6 gas or vacuum interrupter. The results show whether the breaker can clear a fault safely and reliably.

Field

Value

Tests

Timing, contact and dynamic resistance, insulation, SF6/vacuum integrity, mechanism

Breaker Types

SF6, vacuum, oil and air; MV and HV

Equipment

Omicron CIBANO 500 and TM-series analysers

Standards

IEC 62271 and IEEE C37 series

Coverage

Australia-wide, five offices

Tests We Perform

Megavar performs the full circuit breaker test suite on a single visit:

Timing analysis: open, close and trip times, and pole simultaneity
Dynamic contact resistance measurement (DRM) to assess contact and arcing-contact condition
Static contact resistance (micro-ohm) across the main contacts
Insulation resistance and, where required, power factor / tan delta
SF6 gas analysis or vacuum bottle integrity, by interrupter type
Coil current and mechanism / travel analysis
Secondary injection of associated protection where in scope

Breaker Types We Test

Megavar tests every common interrupter and construction type across the medium and high voltage range, including SF6, vacuum, minimum-oil and air-blast breakers, in both live-tank and dead-tank configurations.

When Circuit Breaker Testing Is Required

Circuit breaker testing is required at key points in an asset's life:

Commissioning of new or refurbished breakers
Routine condition-based maintenance
After a breaker has cleared a significant fault
Before return to service following repair
As part of substation maintenance and asset management programs

Standards

Megavar tests circuit breakers in line with the relevant international standards, including the IEC 62271 series for high voltage switchgear and circuit breakers and the IEEE C37 series, within the substation framework of AS 2067.

Why Choose Megavar

Practising HV test engineers using the Omicron CIBANO 500 and TM-series analysers
Testing and commissioning under one roof, so breaker results tie into the wider substation outcome
Five offices: Hobart, Launceston, Adelaide, Newcastle and Gladstone
ISO 9001, ISO 14001 and ISO 45001 certified, licensed in every Australian state
Clear diagnostic reports with pass/fail against rated values

Take it to your team

Capability statement

High-Voltage Testing, Commissioning and Maintenance Services

Primary plant testing, protection and SCADA commissioning, substation maintenance and the design capability behind them.

Clients

What our clients say

Megavar are industry leaders in HV commissioning services, offering high quality commissioning services. They are experts in high voltage commissioning services, and their work is always on time, on budget and to the highest quality.

Shaun ColtonEngineering Manager Substations & BESS, Downer Group

Megavar has repeatedly demonstrated their ability to quickly mobilise their highly skilled technicians to meet project demands and effectively develop solutions in a highly proficient and professional manner.
Megavar have been a pleasure to deal with, and we look forward to continuing to work closely on future projects for years to come.

Matt LawlessDirector – High Voltage Contracting

FAQ

Frequently Asked Questions: Circuit Breaker Testing

What is circuit breaker testing?

Circuit breaker testing measures and verifies a breaker's mechanical and electrical performance, covering timing, contact resistance, insulation and gas or vacuum integrity, to confirm it can open, close and interrupt fault current safely within its rated limits.

What tests are performed on a circuit breaker?

A full test covers timing analysis (open, close and trip times and pole simultaneity), dynamic and static contact resistance, insulation resistance, SF6 gas or vacuum integrity, and coil current and mechanism analysis. Associated protection can be secondary-injection tested where in scope.

Why is circuit breaker timing important?

Timing confirms the breaker opens fast enough to interrupt a fault within its rated time and that all three poles operate together. Slow or unsynchronised operation can leave a fault uncleared or stress the system, so timing is a core acceptance and maintenance measurement.

What is dynamic contact resistance measurement?

Dynamic contact resistance measurement (DRM) records resistance across the contacts as the breaker operates, revealing the condition of the main and arcing contacts that a static reading alone cannot show. It is a key diagnostic for ageing or heavily duty-cycled breakers.

How often should circuit breakers be tested?

Breakers are tested at commissioning, at routine maintenance intervals set by the asset owner, after clearing a significant fault, and before return to service following repair.

What standards apply to circuit breaker testing?

Circuit breaker testing aligns with the IEC 62271 series for high voltage switchgear and circuit breakers and the IEEE C37 series, within the substation framework of AS 2067.

Can Megavar test SF6 and vacuum circuit breakers?

Yes. Megavar tests SF6, vacuum, oil and air breakers across the MV and HV range, selecting the right interrupter-specific checks such as SF6 gas analysis or vacuum bottle integrity.

ISO Certified and Licensed in Every State

Megavar is certified to ISO 9001 (quality), ISO 14001 (environment) and ISO 45001 (safety), and holds electrical contractors licences in every Australian state.

Ready to commission your substation? Contact Megavar today on 1300 730 499 or visit our contact page to request a quote.

Request a quote

Tell us about the job

An engineer replies by the end of the next business day (Monday to Friday, 8:30 am to 5:00 pm). Scope still forming? Send what you have. Outage or urgent fault? Call to discuss the site, access window and mobilisation.

find Attach substation

Name

Company

Phone

Site or substation

Required dates or outage window

Enquiry type

Quote needed by

How did you find us?

Scope, assets and voltage (attach your RFQ if you have one)

Scope status

Scope not finalised yet

Attach RFQ or drawings (optional)

Drag & Drop Files, Choose Files to Upload

* Required.

Megavar Pty Ltd (ABN 88 104 344 765) collects these details, and any file you attach, to prepare your quote, respond to your enquiry and keep a record of it, and to understand how enquiries reach us. If you do not provide them we may not be able to quote. We may share them with our IT, email and business system providers and, where relevant, our insurers and professional advisers, and some of those providers store or process information outside Australia, including in the United States. Our Privacy Policy explains how we handle your information and how to access or correct it or make a complaint.

Talk to us now

1300 730 499 service@megavar.com.au Hobart · Launceston · Adelaide · Newcastle · Gladstone

Doing it in-house?Hire circuit breaker test sets

Explore Our other services

Transformer Testing Services

Power transformer testing and commissioning across Australia. Ratio, winding resistance, SFRA, tan delta and oil diagnostics with a 200+ item test fleet.

Partial Discharge Testing

Partial discharge testing for HV cables, switchgear, transformers, and GIS across Australia. Online and offline PD identifies insulation defects before failure.

Wind Farm EBoP Maintenance and Testing

Wind farm EBoP maintenance and testing by Megavar – relay testing, transformer condition assessment, switchgear servicing, and DGA monitoring. Australia-wide.