Electrical 路 Free
Testing and Maintenance of Transformers and Switchgear
Run, read and record the field tests that keep transformers, breakers, cables, motors and batteries in service: insulation resistance and PI, winding resistance, turns ratio and vector group, tan delta and SFRA, oil and DGA, breaker timing and contact resistance, switchgear thermography, VLF cable tests, motor tests, earth resistance and battery capacity, then turn the results into a maintenance plan.
Inside the course
From the lessons
Maintenance strategies: breakdown, preventive, predictive and RCM
Reliability Centered Maintenance
Transformer tests: winding resistance, turns ratio, vector group and magnetising current
ElectroQC Hub
Transformer oil: breakdown voltage and DGA interpretation (Duval triangle, IEC 60599)
Motwane Manufacturing
Switchgear and MCC preventive maintenance and torque checks
Electrical Code Academy, Inc.
Motors: insulation, winding resistance, surge test (concept) and bearings
OMICRONenergy
Battery and UPS maintenance
Electrical Superintendent
Lesson frames belong to the creators named in the Credits below and are shown from YouTube.
What you will learn
Choose a maintenance strategy for each electrical asset and set intervals from P-F intervals and condition; run and interpret insulation resistance, DAR and PI tests with temperature correction; test transformer winding resistance, turns ratio, vector group and magnetising current; explain tan delta, capacitance and SFRA results; interpret oil breakdown voltage and DGA with Duval Triangle 1 and the IEC 60599 ratios; test circuit breaker contact resistance, timing, coil current, SF6 and vacuum integrity; maintain switchgear and MCCs with torque checks and thermography; test cables with insulation resistance, VLF and tan delta; test motors and look after bearings; measure earth resistance by fall of potential; maintain batteries and UPS; and turn test records into trends, work orders and an annual maintenance plan.
- Choose a maintenance strategy for each asset and set test intervals from the P-F interval and condition
- Run insulation resistance tests and calculate DAR and PI with temperature correction
- Test winding resistance, turns ratio, vector group and excitation current on a transformer
- Interpret tan delta, capacitance and SFRA results against their baselines
- Interpret oil breakdown voltage and DGA with Duval Triangle 1 and the IEC 60599 ratios
- Test circuit breaker contact resistance, timing, coil current, SF6 and vacuum integrity
- Maintain switchgear and MCCs with torque checks and thermography, and test cables, motors, earthing and batteries
- Turn test results into trends, prioritised work orders and an annual maintenance plan
For you
Taking Testing and Maintenance of Transformers and Switchgear from the United States
- Free in the United States, as everywhere, and self-paced: lessons, notes and the final assessment are open at any hour, so your time zone and shift pattern do not matter.
- The optional certificate for learners in the United States is a one-off US$28.99. What you get for it
- Plants across the Americas most often run Allen-Bradley, Siemens and Inductive Automation; each has its own free course to take next.
- See automation and engineering jobs in the United States, and what the industry looks like in Houston, Detroit and Chicago.
- EDWartens also has a regional site for the United States, for classroom training and local support: edwartens.com/us.
The course project 路 about 8 hours
Condition review of a 2 MVA transformer and its 11 kV breaker from a year of test results
Read a year of oil, DGA and electrical test results for a 2 MVA, 11/0.433 kV transformer and the vacuum breaker that feeds it, flag what is degrading and why, write prioritised work orders, and set the next test intervals. The sample pack shows each document for a district cooling plant in Dubai.
Sample document pack, 5 documents, filled in for the scenario
- RegisterAsset and baseline register: TR-2 and CB-2
- Test report2026 test results: TR-2 oil, DGA and electrical tests, and CB-2
- ReportCondition assessment of TR-2 and CB-2, 2026
- Punch listWork-order list from the 2026 condition review
- PlanTest intervals for TR-2 and CB-2 from 2026
Read inside the course and download as a workbook. The project is optional practice, marked when you submit it; the certificate needs only the modules and the final assessment.
Course content
13 modules 路 55 lessons 路 19h 7m
In order, at whatever pace suits you. Each module ends with a practice task that builds on the last.
- 01Maintenance strategies: breakdown, preventive, predictive and RCM4 lessons33m
- 02Insulation resistance, PI and DAR with an insulation tester4 lessons1h 41m
- 03Transformer tests: winding resistance, turns ratio, vector group and magnetising current9 lessons1h 35m
- 04Tan delta and capacitance, and SFRA (concept)4 lessons2h 41m
- 05Transformer oil: breakdown voltage and DGA interpretation (Duval triangle, IEC 60599)4 lessons1h 31m
- 06Circuit breakers: contact resistance, timing, coil current, SF6 and vacuum checks7 lessons1h 41m
- 07Switchgear and MCC preventive maintenance and torque checks2 lessons1h 29m
- 08Cables: insulation resistance, VLF and HV withstand, partial discharge (concept)4 lessons56m
Requirements
- Who it is for
- Intermediate. For maintenance engineers and technicians, testing and commissioning engineers, and final-year electrical students. You should know how a transformer, a circuit breaker and an induction motor work and be able to read a single-line diagram. Protection relays are covered in the separate Protection Relays course.
- Software
- A spreadsheet (LibreOffice Calc is free) for test records, temperature corrections, Duval triangle percentages and trend lines. No test-set software is needed: every test is planned and its results worked on paper. What to download, and how
- Hardware
- None required. Access to an insulation tester, a micro-ohmmeter or a turns ratio tester at work or college makes the modules far more useful, but only under your site's safety rules and a permit to work.
Software you need
What to download, where from, what it costs and how to install it. Every link goes to the maker's own site, never a mirror.
Nothing to install
A spreadsheet is enough for the test records, temperature corrections, Duval triangle percentages and trend lines; free online Duval triangle calculators are useful for checking hand plots.
Optional
Useful, not needed to finish the course.
- 01Free
LibreOffice
The Document Foundation
- Runs on
- Windows 10 or 11, macOS 11 or newer (Intel or Apple silicon), Linux
- Account
- None needed
- Size
- up to 1.5 GB of disk space on Windows
LibreOffice is free, open-source software under the Mozilla Public License 2.0, for any use including business. Calc is its spreadsheet.
Steps
- 1.Open the LibreOffice download page.
- 2.Check the page has picked your operating system, then select Download.
- 3.Run the installer (administrator rights are needed on Windows).
- 4.Start LibreOffice Calc for spreadsheet work.
- 5.Save as .xlsx if you need to share files with Excel users.
- Choose the latest main version unless your organisation asks for the older, more conservative release.
Official download pagelibreoffice.org
Checked against each maker's own page on 27 September 2026. Trial lengths and editions change; the maker's page is the final word.
Testing and Maintenance of Transformers and Switchgear at a glance
Testing and Maintenance of Transformers and Switchgear is a free, self-paced online course from EDWartens for maintenance, testing and commissioning engineers and technicians who test and maintain transformers, switchgear, cables, motors and batteries. It has 13 modules and 19h 7m of video lessons by ElectroQC Hub, Megger, OMICRONenergy and others, with written notes and worked problems, a practical project with a document pack and a 15-question final assessment (pass mark 60%). Learning is free with an account; an optional certificate with a public verification code is issued when you pass. Last updated 27 September 2026.
All course factsHide course facts
- Price
- Free, for good. No trial, no card. The only paid item is the optional certificate, a small one-off fee.
- Who it is for
- Maintenance, testing and commissioning engineers and technicians who test and maintain transformers, switchgear, cables, motors and batteries
- Format
- 13 self-paced modules, 19h 7m of video, written notes, a practice task per module and one final assessment.
- Level
- Intermediate. Intermediate. For maintenance engineers and technicians, testing and commissioning engineers, and final-year electrical students. You should know how a transformer, a circuit breaker and an induction motor work and be able to read a single-line diagram. Protection relays are covered in the separate Protection Relays course.
- Brand
- Vendor-neutral
- Software
- A spreadsheet (LibreOffice Calc is free) for test records, temperature corrections, Duval triangle percentages and trend lines. No test-set software is needed: every test is planned and its results worked on paper.
- Hardware
- None required. Access to an insulation tester, a micro-ohmmeter or a turns ratio tester at work or college makes the modules far more useful, but only under your site's safety rules and a permit to work.
- Certificate
- Optional EDWartens Certificate of Completion, verifiable by code. Not a vendor credential.
- Video lessons by
- ElectroQC Hub, Megger, OMICRONenergy, AEMC Instruments, Safety+Health YouTube channel (independent creators, credited below)
- Language
- English
- Last updated
- 27 September 2026
A shareable EDWartens certificate
Finish every module and pass the final assessment, and the optional EDWartens certificate is yours. It carries a unique verification code on a public page anyone can check, so it stands up when a recruiter looks it up. See it below.
The course itself stays free whether or not you ever buy one.
Stuck? Ask a practising engineer
A free course usually means a comment section and hope. This one does not. Every module has an Ask-your-trainer panel that reaches the same engineers who teach our paid programme: people who commission panels for a living, not moderators.
Pairs well with
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PLC programming 路 FreeSiemens TIA PortalFrom zero electrical knowledge to a working, simulated S7-1200 program, for nothing.
PLC programming 路 FreeSiemens TIA Portal in Three HoursThe first three hours of the Siemens TIA Portal course, cut to end on a win: what a PLC is, how it is wired, a project configured in TIA Portal, and your first ladder program running in simulation. Finish it in an evening or two, earn a certificate, and carry straight on into the full course.
PLC programming 路 FreeTIA Portal: Build a MachineOne machine, start to finish. Take a bottle filling line from a written specification and an I/O list to a structured S7-1200 program with a fill station, a capper, a reject sorter and an operator screen with alarms, then test it against a written record and archive it for hand-over. The lessons are the reference; the machine is yours, and it is what you submit.More free courses: Free electrical design and control panel courses 路 Free power system and ETAP courses
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Common questions
Who is this transformer testing course for?
Maintenance engineers and technicians, testing and commissioning engineers, and final-year electrical students who test and look after transformers, switchgear, cables, motors and batteries. It suits people applying for testing and commissioning and electrical maintenance roles worldwide, notably in the Gulf, where these tests are everyday work.
What do I need to know before starting?
How a transformer, a circuit breaker and an induction motor work, and how to read a single-line diagram. No test-set experience is needed: each test is explained from what it measures to how its result is judged.
Do I need test equipment or software?
No. Every test is planned and its results worked on paper or in a free spreadsheet such as LibreOffice Calc. Access to an insulation tester, micro-ohmmeter or turns ratio tester at work makes the course more practical, but only under your site's safety rules and permit to work.
Which standards does the course use?
It works with IEEE 43 for insulation testing of machines, IEC 60076 for transformer tests, IEC 60156, IEC 60422 and IEC 60599 for oil and dissolved gas analysis, IEC 62271 for breakers, IEEE 400.2 for VLF cable testing, IEEE 81 for earth resistance, IEEE 450 for batteries and NFPA 70B for maintenance programmes. It paraphrases these standards rather than reproducing them; check the edition your client specifies.
How is this different from the Protection Relays course?
This course tests and maintains the primary equipment: transformers, breakers, cables, motors, earthing and batteries. Protection Relays: Settings, Testing and Commissioning covers the relays that protect them, with CTs, settings, secondary injection and trip checks. Taking both covers most of a testing and commissioning engineer's work.
How long does the Testing and Maintenance of Transformers and Switchgear course take?
About 25 hours of video lessons, notes and practice, taken at your own pace; the videos alone are about 19 hours. The optional project, a condition review of a transformer and its breaker from a year of test results, takes about 8 hours more.
Is the course free, and what certificate do I get?
Every module, the notes, the project and the final assessment are free. If you pass the 15-question final at 60 percent you can get an EDWartens Certificate of Completion, with a number anyone can verify on our site. It is a certificate of completion, not a NETA certification, a licence or a qualification from any test-equipment maker.
What jobs does it lead to?
Electrical maintenance engineer and technician, testing and commissioning engineer, substation maintenance and transformer service roles with utilities, plants, facilities contractors and testing companies. Employers will still expect hands-on time with test sets, which this course prepares you to use well.
What you walk away with
Your certificate for Testing and Maintenance of Transformers and Switchgear
Finish the course, pass the final, and this is the document with your name on it.
Verifiable by anyone
Adds to LinkedIn in one click
QR code on the certificate
Names what you can do
A permanent link
Earned, not attended
Learning is free. The certificate is optional.
Add it now and pay only when you have finished the course, or come back for it later. One-off, US$28.99, with a receipt.
Issued by EDWartens, the training division of Wartens, as a Certificate of Completion for this self-paced course. Sold by Wartens Ltd (England and Wales). It is not a vendor certification, a university award or a CPD-accredited activity, and it does not certify competence on live equipment. Delivered electronically; see the refund policy.
Credits
Who made the video lessons
The video lessons in this course were created by the people below, not by EDWartens. Every lesson streams from its creator's own YouTube channel; EDWartens neither hosts nor sells that footage, and the creators are not affiliated with EDWartens and do not endorse this course. What EDWartens wrote is the study plan, the notes, the practice tasks and the assessments.
- ElectroQC Hubthe Power Transformer Testing playlist on a 100 MVA transformer: nameplate, insulation resistance with and without the HV link, core insulation, winding resistance, turns ratio, vector group, excitation current, magnetic balance, short-circuit impedance, zero-sequence impedance, tan delta and capacitance, SFRA and dielectric frequency response
- Megger USwebinars on insulation resistance testing, transformer turns ratio best practice (https://www.youtube.com/watch?v=Q6dCoXA-xpc), power factor and DFR for insulation assessment (https://www.youtube.com/watch?v=kot_OkvL3F8) and practical VLF cable testing (https://www.youtube.com/watch?v=lDOwXagByV8)
- Meggermedium and high-voltage circuit breaker testing, VLF tan delta (https://www.youtube.com/watch?v=0aBUGgfNDIE) and partial discharge tests on cables (https://www.youtube.com/watch?v=U-UIcDAK3oM), partial discharge on surge testing with the Baker DX (https://www.youtube.com/watch?v=dBwVVWf_dR0), battery load testing practice (https://www.youtube.com/watch?v=INn6FO2WdUE) and running a battery discharge test (https://www.youtube.com/watch?v=XVqNf-Qrjjs)
- Megger Australiaa webinar on medium and high-voltage circuit breaker testing
- OMICRONenergycircuit breaker testing with CIBANO 500 on medium and high-voltage breakers (https://www.youtube.com/watch?v=COvybldgmWw, https://www.youtube.com/watch?v=vCcvDZCJ6Ik) and the Basics of Rotating Machine Testing series: insulation resistance and PI, tan delta, voltage withstand, partial discharge and the Energy Talks overview (https://www.youtube.com/watch?v=-7tjscOg08w)
- AEMC Instrumentsfall-of-potential earth resistance testing in full, and understanding ground resistance testing (https://www.youtube.com/watch?v=NP9Jbdi_k6s)
- Global Test Supplya webinar with Megger on how ground testing keeps people safe: fall of potential, clamp-on and continuity testing
- Safety+Health YouTube channelwebinars on NFPA 70B and the maintenance of electrical equipment, and on building an electrical maintenance programme (https://www.youtube.com/watch?v=B_bneVLRNLc)
- Vector Powerunderstanding the 2023 edition of NFPA 70B
- Electrical Code Academy, Inc.the NFPA 70B and NETA severity scales for electrical thermography
- GlobeCore companythe Duval triangle method for transformer diagnostics
- Oil Analysisdissolved gas analysis interpretation
- Gulf Bio Analytical Groupdissolved gas analysis with a transformer oil gas analyser
- Motwane Manufacturingthe transformer oil breakdown voltage test procedure, demonstrated
- The Electrical Guyvacuum circuit breaker maintenance and testing
- Electrical in IndustrySF6 gas testing for moisture, purity and decomposition products
- IPECLTDwhat partial discharge is
- BakerInstrumentCosurge tests on motor windings with the Baker DX
- TPC Traininga webinar on electric motor troubleshooting and maintenance techniques
- Electrical Superintendentmotor maintenance, and substation battery impedance testing (https://www.youtube.com/watch?v=q0RMYkSSFfE)
- ITM Instruments Inc.a webinar on UPS and battery maintenance
- Reliability Centered Maintenancewhat reliability-centred maintenance is
- Skill Torquereliability-centred maintenance explained
- Engineering Presentationsthe philosophy of reliability-centred maintenance
- Asset Insightsthe three main maintenance strategies compared, used as the revision lesson before the final
If you are one of these creators and would like a lesson removed or credited differently, write to info@wartens.com.