Testing and commissioning services

Transformer Testing Services Australia

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

Comprehensive Power Transformer Testing and Diagnostics Across Australia

Power transformers are the single highest-value assets in any substation. A failure can cost millions in replacement, lost production, and consequential damage. Megavar provides comprehensive transformer testing for commissioning, routine maintenance, condition assessment, and post-fault investigation of power transformers from 11 kV distribution class through to 500 kV EHV transmission class.

Our testing methodology detects incipient faults at the earliest possible stage, enabling asset owners to make informed decisions about maintenance, refurbishment, or replacement.

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

Megavar engineer performing transformer testing with Omicron CPC 100 in Australian substation

Electrical Tests

Turns ratio (TTR) – Voltage ratio on all tap positions. Tested to IEC 60076-1 with accuracy better than 0.1%.
DC winding resistance – All phases and tap positions to detect poor connections, broken strands, and high-resistance joints. Includes OLTC contact resistance trending.
Insulation resistance (IR) – Winding-to-winding and winding-to-earth at standard test voltages. Includes polarisation index (PI) and dielectric absorption ratio (DAR).
Insulation power factor / tan delta – Dielectric dissipation factor to assess insulation condition, moisture, and contamination. Standard and elevated voltages with tip-up analysis.
Sweep frequency response analysis (SFRA) – Frequency-domain measurement to detect winding deformation, core displacement, and transport damage. Compared against factory baselines. Measured with the FRANEO 800 sweep frequency response analyser.
Capacitance measurements – Winding and bushing capacitance for condition trending and bushing serviceability.
Short-circuit impedance – Impedance measurement to detect winding displacement. Compared against factory certificates.
Excitation current – No-load excitation to detect core faults, shorted turns, and core insulation degradation.

Oil Testing

Dissolved gas analysis (DGA) – Insulating oil sampling for dissolved gas concentrations. Interpreted using Duval Triangle, Rogers Ratio, and Key Gas methods.
Standard oil tests – BDV, moisture, acidity, interfacial tension, colour, dissipation factor. Tested to AS 1767 and IEC 60422.
Furan analysis – Furanic compound measurement to estimate cellulose insulation degradation and remaining life.

Mechanical and Accessory Testing

OLTC testing – Dynamic resistance measurement (DRM), transition timing, motor current analysis, and compartment oil sampling.
Bushing testing – Tan delta, capacitance, and power factor. Comparison against factory values and trend data.
Cooling system – Fan/pump operation, oil flow, temperature gauges, and cooling control logic verification.

When Transformer Testing Is Required

New installation commissioning (site acceptance testing)
Routine maintenance programmes (condition-based or time-based)
Post-fault investigation following protection operation or through-fault
Condition assessment prior to asset acquisition or insurance renewal
Pre- and post-transport testing for relocated transformers
End-of-life assessment and remaining-life estimation

Standards

All testing per AS 60076, IEC 60076, IEEE C57.12.00, IEEE C57.12.90, CIGRE TB 761, and relevant NSP maintenance standards. Equipment calibrated with NATA-traceable certificates.

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.

Capability statement

High-Voltage Resonant Hipot Testing

AC withstand testing to 500 kV on Megavar-owned resonant test sets, with partial discharge measurement.

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 Transformer Testing Services Australia

What is SFRA and why is it important?

Sweep Frequency Response Analysis measures winding impedance across a wide frequency range. The unique frequency trace is compared against factory baselines. Any deviation indicates mechanical changes – winding deformation, core displacement, or loose clamping. Critical after transport, through-faults, or seismic events.

How often should power transformers be tested?

Common approach: annual DGA sampling, routine electrical testing every 4–6 years for modern units, and condition-based assessment for transformers over 30 years. Critical or defective units may need more frequent testing.

What is dissolved gas analysis (DGA)?

DGA analyses gases dissolved in transformer oil. Different fault types produce characteristic gas signatures. Measuring hydrogen, methane, ethylene, acetylene concentrations detects incipient faults before failure. Widely regarded as the single most important transformer monitoring tool.

What voltage classes does Megavar test?

We test transformers from 11 kV distribution through to 500 kV EHV transmission class. Our Omicron CPC 100 is rated for the full range.

Does Megavar provide condition assessment reports?

Yes. Detailed reports include all results, factory data comparison, DGA interpretation, trend analysis, and actionable recommendations for maintenance, monitoring, or further investigation.

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 book your transformer testing? Contact Megavar today on 1300 730 499 or visit our contact page to request a quote. To see what the testing involves first, read our transformer testing guide.

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

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