Commercial Electrical Systems & Math
Bridge the gap between roughing-in conduit and passing commercial certification. Master three-phase power, precision voltage calculations, transformer connections, and motor circuit sizing.
Like Duolingo, but for Commercial Electrical Systems & Math. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
A short one: 11 levels across 2 sections, about 22 minutes end to end, roughly 4 days at five minutes a day. It moves through Conductor Math & Three-Phase Power and Commercial Equipment & Protective Devices. It assumes you already know the basics.
Free forever · No credit card · iPhone & Android
Key ideas in Commercial Electrical Systems & Math
- Single-phase circuits double length to account for the return path.
- Three-phase line-to-line current vectors cancel out, using sqrt(3) (1.732).
- Using the 2 multiplier on three-phase overestimates conductor gauge.
- Continuous loads must be multiplied by 125% to find min conductor ampacity.
- Ambient temp and conduit fill factors adjust wire's baseline table ampacity.
- Overcurrent breaker size is set after conductor derating meets demand.
- Upsizing phase conductors lowers circuit impedance over long runs.
- Grounding conductors must be upsized proportionally by circular mil area.
- A undersized ground conductor risks inadequate fault current to trip breakers.
- Inductive coils create magnetic reactance that shifts current out of phase.
- Lagging power factor drives higher voltage drop than DC resistance alone.
- Commercial motor feeders require impedance tables rather than pure Ohm's law.
- Line-to-line voltage in a wye system equals phase voltage times 1.732
- A 480Y/277V distribution panel delivers 480V across phases
- The 120-degree angular separation prevents simple direct addition
- The high-leg phase sits at 208V to ground due to center-tapped winding geometry
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Commercial Electrical Systems & Math the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
When calculating voltage drop for a balanced three-phase circuit, what multiplier replaces the single-phase factor of 2?
Get it right to open this lesson and 10 more in the app.
Where Commercial Electrical Systems & Math takes you
- 1
Conductor Math & Three-Phase Power
- Field Calculations for Voltage Drop and Derating
- Three-Phase Distribution: Wye vs. Delta
- 2
Commercial Equipment & Protective Devices
- Commercial Transformers: Sizing, Taps, and Grounding
- Motor Circuits and Fault-Current Coordination
2 sections · 4 units · 11 levels. Built to play, not to enroll.
You pick the voice
Commercial Electrical Systems & Math is taught in the The Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
More Technology on Tomo
Electrical Power Systems
Analyze complex power distribution networks, diagnose high-frequency transients and harmonics, and design resilient protection schemes. Built for experienced electricians and engineers ready to tackle industrial-scale electrical engineering challenges.
Electricity and Practical Circuits
Move beyond basic textbook formulas to build a working intuition for real circuits. Learn how components behave under load, diagnose tricky faults, and master the forces shaping electrical systems.
How Electrical Circuits Work
Demystify electricity by building, measuring, and troubleshooting real circuits. Learn how voltage, current, and resistance interact to power everyday devices safely.
Electrical Systems for Boats and Audio
Learn to wire clean, reliable direct-current systems built for harsh marine environments and high-output audio gear. Master safe terminations, noise-free sound circuits, and battery management from the ground up.
Ohm's Law in Circuit Design
Bridge the gap between textbook formulas and reliable hardware. Learn how professional engineers apply Ohm's law to size real loads, account for parasitic resistance, troubleshoot ground drops, and manage thermal limits.
Practical Electronics: From Circuits to Chips
Learn how electricity is harnessed, amplified, and programmed to power modern hardware. Explore real-world circuits from basic LEDs and transistors up to microcontrollers, op-amps, and commercial silicon chips.
Start Commercial Electrical Systems & Math today.
Download Tomo, search Commercial Electrical Systems & Math, and play your first lesson in under a minute.