XFMR Lab Enterprise
Classroom Transformer Trainer
Free
The classroom edition of XFMR Lab, for utilities and lineman training programs.
Wire it. Energize it. Find out what went wrong before you do it on a pole. XFMR Lab simulates utility distribution transformer banks with the meters, fuses and fault behavior you would see on the real thing. Built by a working journeyman lineman for apprentices and crews who would rather make their mistakes in an app than in the field.
This edition is for organizations. Licensed Code Access Only: your school or employer gives you a code, and the app opens. There is nothing to buy inside the app. Individuals can find the public edition on the App Store as Lineman's Reference - XFMR Lab.
FOR INSTRUCTORS:
The Instructor Board creates a class you run from an iPad or phone. Start a session, give students the join code, and assign labs to the whole class, a group or one student. As they work you see each student's wiring live on your screen, along with failed checks, blown fuses, hazards and their score. Students can raise a hand, skip a lab for a second look, or say I don't know; you can mark a lab assisted when you walked them through it. Homework sessions stay open for days with a due time. At the end, the results are on your board and export cleanly as a CSV you can download or email.
FOR STUDENTS
Join a session with a code and a nickname. Your instructor sees your progress while a lab is open, and the card on your screen says exactly what they can and cannot see. Outside a session, every lab and reference below is yours to practice on.
THE LABS
Single Phase: Single Bushing Topside, Dual Bushing Topside.
Three Phase, closed banks: Delta-Delta, Delta-Wye, Wye-Delta, Wye-Wye.
Three Phase, open banks: Open Delta-Delta, Open Wye-Delta.
Misc: Paralleling, 4th Cutout, Death Traps.
Advanced: Straight 480, 240/480, 277/480, Corner-Grounded 240/480, Wye-Wye 5-Wire (120/240 plus 120/208).
Sandbox Lab (Beta): free-form wiring with a live phasor solver.
TOOLS AND REFERENCE
Volt, ohm and rotation meters with real fault behavior. Nameplate and secondary coil inspection. Reference Diagrams, Basics and the Advanced Transformer Reference. A rebuilt Tutorial of 8 hands-on chapters, and the Training track of lessons.
Classic Quiz grades all 14 quiz-eligible labs: blowing fuses and failing Check Work subtract from your score. Advanced Quiz gives you job-site information, has you pick the nameplate and coil configuration, then wire it. Learning Mode walks apprentices through every wrong-connection check one at a time; journeymen turn it off for the test.
Class sessions send a student's nickname, results and live wiring to the instructor's board. The nickname is erased from our server when the class ends; results stay with the seat, not a name, and live wiring is never stored. Nothing is used for tracking or advertising.
Built for linemen, by a lineman.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
What's new in 2.0.7
- Instructor Board: a hand going up now drops a banner over whatever you are looking at, and the open card shows that student's hand and wait.
- Instructor Board: recalling the last student working an assignment ends the assignment.
- Students: the I don't know card, the ended-lab notice and the clear-log card lay out cleanly on every phone; an assisted lab reads "marked assisted: does not affect your score".
- The access code screen says plainly when a code was replaced, when a program is on hold, and how many hours a short licence has left.
- A privacy policy link in Settings, on the Join Session card and on the access code screen.
- Sandbox: the Wye 5-Wire bank's series pot is a 50, and the ratings panel knows what each of its coils can carry.
The developer, Digital Apprentice LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Contact Info
- Identifiers
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Digital Apprentice LLC
- Size
- 69.3 MB
- Category
- Education
- Compatibility
Requires iOS 16.0 or later.
- iPhone
Requires iOS 16.0 or later. - iPad
Requires iPadOS 16.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Digital Apprentice LLC