Lineman's Reference - XFMR LAB

Lineman's Reference - XFMR LAB

Interactive Transformer Lab

123 ratings
42 reviews
$19.99

Details

  • Released
  • Updated
  • September 12, 2021
  • July 4, 2026

Features

Lineman's Reference - XFMR LAB screenshot #1 for iPhone
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About

This interactive simulator allows users to study and learn transformer connections. Test your wiring with various meters, and experience consequences of improper connections. Includes reference diagrams, informational material, and a quiz mode to test knowledge.

Transformer connection simulation
Volt, ohm, and rotation meters
Abnormal voltage and fuse explosion simulation
Transformer nameplate and coil inspection
Quick reference diagrams
Informational reading material
Quiz and advanced quiz modes
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What's New in Lineman's Reference

2.0.3

July 4, 2026

XFMR Lab 2.0 — the biggest update since launch. NEW: Built-in Transformer Training (replaces XFMR Info). Six guided lessons take you from "what's a transformer?" to wiring a 3-pot bank — Start Here, Dual H Bushings, The Tap Changer, Three-Phase, Bank Identification, and Your First Bank: Delta-Wye Closed. More lessons on the way. More lessons on the way soon! NEW: The Sandbox (Beta) — wire anything from scratch in a fully customizable lab, with live, vector-based voltage and fault logic baked in. NEW: Death Traps — scenario-based transformer traps linemen run into, and how to navigate them safely (3 scenarios with more on the way). NEW: User Customizations — set the spec of your own labs: grounding, parallel coil cutover direction, requiring the 4th cutout, tap changers, and more. NEW: Bank ID quiz — a beginner quiz tied to the Training lessons; identify primary and secondary wirings on sight. NEW: Stats — track lab completions, quiz scores, and for-fun numbers like how many fuses you've blown. ALSO: • A brand-new look across every lab — new graphics, sharper and easier to read in the field. • Tap changer, nameplate, and secondary coil animations. • Parallel the secondary coils by hand in wye-secondary labs. • Advanced labs can now be wired Wye OR Delta on the topside. • Voltmeter now drags with two fingers; readings update as the leads move. 2.0 is FREE for everyone who already owns XFMR Lab — and every future update is free, too. One-time purchase. Thank you for years of feedback and encouragement.

More

Charts

Top Paid

🥉 3

Education

The app has maintained its position at 3 recently.

Last updated on July 23, 2026.

Top Paid

📉 89-8

Global

This app dropped -8 positions in Global chart.

Last updated on July 23, 2026.

User reviews

Very useful!!!

I’m a co-op student and I play around with this app a lot! It’s definitely going to help a lot in the future!!

Good app

Learning a lot from this app. Only problem I’ve come across is how to tie the H1/H2 bushings to the tank ground and neutral

WYE Delta is wrong

Your eye delta is wrong. Other than that good app.

Needs a bug fix

Great app just noticed that on some of the banks you can’t bus the secondary x2 to x2 bushing for delta secondary’s. It use to work but if the developers can fix that then it would get that 5th star in my book

Response from developer

Why would you want to bus Delta secondaries across X2's? Delta secondary connections can only have one neutral reference. Unless I am misunderstanding you, which may be the case. Please reach out to me at info@digitalapprentice.net!

Very helpful

The app has some flaws but nothing you can’t work around. Helped me a lot on learning transformer configurations.

Response from developer

Please reach out to me at info@digitalapprentice.net with any issues so I can get them corrected. Thanks!

Developer apps

FAQ

What does the Lineman's Reference - XFMR LAB app do?

This app is a fully functional transformer lab simulator designed for linemen and apprentices. It allows users to study and learn various transformer connections, test their wiring with meters, and understand the consequences of improper connections. It also provides reference materials and quiz modes.

What are the key features of this transformer simulator?

Key features include interactive simulation of single-phase and three-phase transformer banks, testing connections with volt, ohm, and rotation meters, simulating abnormal voltages and exploding fuses, inspecting transformer nameplates and secondary coils, quick reference diagrams, informational reading material, and quiz modes to test knowledge.

Is this app free to use?

Yes, based on the provided information, the app is free to use and does not have in-app purchases or ads. The company also offers a 'Company Customized Experience' which may involve separate arrangements.

What kind of transformer configurations can I learn and test?

The app includes labs for various configurations such as Single Bushing Topside, Dual Bushing Topside, Delta Delta Closed, Delta Wye Closed, Wye Delta Closed, Wye Wye Closed, Delta Delta Open, Wye Delta Open, Paralleling, 4th Cutout, Troubleshooting, Tutorial, Straight 480, 240/480, 277/480, Corner Grounded 240 or 480, and Wye Wye 5 Wire (120/240 & 120/208).

How does the quiz mode work?

The quiz mode allows you to test your transformer wiring knowledge by completing a predetermined assortment of labs at random. Blowing fuses and attempting to check work will subtract from your overall score out of 100. There is also an 'Advanced Quiz' where you receive job-site information and must choose the correct transformer configuration.