Professional Training Programs
49Applied Electrical Engineering Professional Program
โจ Premium ContentPractical electrical engineering from an engineering perspective โ without the unnecessary university math. 16 modules from fundamentals through certification, 9 complete real-project design packages (home, apartment, office, school, hospital, industrial plant, pump station, data center, substation), a 12-template documentation kit, and a certificate of completion. One-time purchase, no account required.
Explore the Full Curriculum โApplied Power Systems Engineering Professional Program
โจ Premium ContentGeneration, substations, transmission, protection, SCADA, and commissioning as one integrated curriculum. 20 modules from fundamentals through certification, 5 complete real-project design packages (69/13.8kV distribution substation, utility solar farm, combined cycle power plant, hydroelectric plant, industrial power distribution system), a 12-template documentation kit, and a certificate of completion. One-time purchase, no account required.
Explore the Full Curriculum โKnowledge Articles
70Frequently Asked Questions
A Professional Engineer (PE) license is for engineers who design electrical systems and stamp drawings; it requires an engineering degree, the FE exam, ~4 years of experience, and a PE depth exam through NCEES and your state board. An electrician trade license (journeyman, master, contractor) is for tradespeople who install and maintain systems; it requires an apprenticeship and a state/local NEC-based exam. They are separate credentials with separate boards.
Most power-system engineers take the PE Electrical and Computer: Power exam. NCEES also offers PE Electronics, Controls & Communications and PE Computer Engineering depth exams. All are computer-based, 80 questions, taken after passing the FE and gaining qualifying experience.
Typically you complete about four years (~8,000 hours) of documented apprenticeship plus related classroom instruction, then pass a computer-based, open-book exam based on the National Electrical Code (NEC). Exact hours and prerequisites vary by state and local jurisdiction.
Mostly yes, but in different ways. The FE and PE exams are open-book using an on-screen NCEES reference handbook only. Trade exams (journeyman, master, contractor) let you bring a tabbed, highlighted current NEC. All are computer-based and time-pressured, so fast code lookup is essential.
It is a separate, limited-scope license for low-voltage systems such as fire alarm, data/communications, security, and audio-visual cabling (generally Class 2/3 circuits). It has its own exam and experience requirements that vary by state and system class.
NCEES publishes annual first-time pass rates for the PE Electrical and Computer: Power exam, which typically run in the roughly 50-60% range for first-time takers and noticeably lower for repeat takers. Rates shift year to year as NCEES updates the exam specification, so check the current NCEES pass-rate report for the exact figure before you plan around it.
The FE Electrical and Computer exam has a first-time pass rate generally in the 60-75% range according to NCEES data, making it somewhat more approachable than the PE depth exams โ largely because it is taken close to graduation while coursework is still fresh, and it draws from a broad but foundational topic list rather than deep specialization.
Pass rates for journeyman electrician exams vary by state/jurisdiction and testing vendor (PSI, Prometric, etc.) and are not centrally published the way NCEES rates are, but the exam is widely considered manageable for well-prepared apprentices โ the main failure point is usually NEC lookup speed under time pressure, not the underlying electrical theory.
Engineering Calculations
31Concept Explainers
24Why a copper wire โ not the ground rod outside your house โ is what actually keeps you from getting shocked. Side-by-side illustrated comparison of the fault current path with and without a proper equipment grounding conductor.
The single most confused pair of terms in electrical work. Grounding connects a system to earth; bonding connects metal parts to each other โ and only one of them keeps two touchable surfaces at the same voltage.
Voltage is a difference between two points. Current is a flow through a point. Illustrated loop diagram showing why current doesn't shrink after passing through a lamp โ energy is converted, current is conserved.
โ3 isn't an arbitrary three-phase constant โ it's the phasor difference between two voltages, or two currents, 120ยฐ apart. Illustrated wye voltage triangle and delta current triangle, side by side.
One transformer, two wildly different ohm values depending which side you measure from โ and exactly one per-unit value that works on both. Why base values make network studies possible.
An induction motor's rotor never quite catches up to its own rotating magnetic field โ and that's not a flaw. Illustrated rotor-slip diagram plus a torque-vs-slip curve showing why zero slip means zero torque.
Why energizing an unloaded transformer can momentarily draw 8-12x its full-load rated current โ and trip a breaker sized for full load. Illustrated B-H saturation curve plus a decaying inrush waveform vs. a sustained fault.
A node that behaves like 0V without a wire to prove it, and two op-amp inputs that act shorted together while drawing zero current. Illustrated inverting-amplifier and open-loop-gain-plus-feedback diagrams.
One is built to keep its two inputs equal; the other is built to slam its output to one of two extremes the instant they differ. Illustrated side-by-side circuits plus a spec comparison table.
Real power does the work, reactive power builds the fields, and apparent power is what your wires and breakers actually have to survive. Illustrated power triangle plus a good-PF-vs-poor-PF comparison at identical real power.
The symmetrical RMS fault current from a short-circuit study is the calm, steady-state number โ not the worst one. Illustrated asymmetrical waveform plus a low-X/R-vs-high-X/R comparison at the same steady-state current.
A spinning motor is quietly also a generator. Illustrated equivalent circuit showing why counter-EMF makes starting current so much higher than running current, plus the power-flow reversal that turns overspeeding into regenerative braking.
Why a VFD can't just keep raising frequency forever and expect full torque at any speed. Illustrated torque-vs-speed curve and V/f-vs-speed chart showing exactly where voltage caps out and flux starts weakening.
An ideal voltage source holds voltage constant no matter the load current; an ideal current source holds current constant no matter the load voltage. Illustrated V-I characteristic curves showing why a real battery's terminal voltage droops under heavy load โ cranking a car engine dims the headlights.
Voltage drop rises linearly with current; power loss in the same conductor rises with current squared. Illustrated chart showing why doubling current only doubles voltage drop but quadruples the heat โ and why NEC voltage-drop guidance and ampacity tables are two genuinely different constraints on the same wire.
A grounded system trips fast and hard on a single fault. A floating (ungrounded) system barely notices a first fault at all โ and that's a deliberate reliability tradeoff, not an oversight. Illustrated fault-current path comparison showing why hospitals' isolated power systems use exactly this design.
Every ground fault is a kind of short circuit. Not every short circuit is a ground fault โ and that one-way relationship is exactly why ground-fault protection exists as its own, more sensitive detection scheme. Illustrated comparison of a bolted phase-to-phase fault vs. a phase-to-ground fault's current path.
A short circuit is the electrical event. Arc flash is a hazardous byproduct that happens when that current arcs through air instead of solid metal โ and its incident energy depends on clearing time as much as fault current. Illustrated bolted-vs-arcing comparison plus an incident-energy-vs-clearing-time chart.
Selectively coordinated protection means only the device closest to a fault opens โ every upstream device stays closed. Illustrated time-current curve comparison showing properly separated (selective) vs. overlapping (cascading, non-selective) device curves, and why NEC 700/701/708 mandate it.
%Z isn't an efficiency rating โ it's the single biggest limiting factor on available fault current at a transformer's secondary. Illustrated side-by-side comparison showing how a lower-%Z transformer, even at the same kVA rating, can silently push fault current above a downstream panel's AIC rating.
A perfectly balanced three-phase load returns zero neutral current in theory. In practice, load imbalance and harmonic distortion both put current back โ through two genuinely different mechanisms. Illustrated phasor diagram: balanced currents canceling vs. an unbalanced case leaving a residual.
Triplen harmonics (3rd, 9th, 15th...) don't cancel across three phases the way the fundamental does โ they land perfectly in phase and add arithmetically at the neutral, which can make neutral current exceed any individual phase's current. Illustrated waveform comparison of canceling vs. adding harmonics.
An overload is sustained excess current in the normal current path; a short circuit is a near-instant massive current spike from a fault. Illustrated time-current curve showing exactly why thermal-magnetic breakers carry two separate trip elements instead of one.
Available fault current is a property of the system, set by upstream impedance; interrupting rating (AIC) is a nameplate property of the equipment. Illustrated one-line diagram showing available fault current decreasing at successive downstream points, checked against each point's installed AIC rating.
Electrical PE & Electrician License Exam Prep
18Interactive Readers
20Interactive 14-section NEC 2023 guide: load calculations, ampacity tables, motor circuits, grounding, conduit fill, voltage drop, and one-line diagram reading. First 3 free to preview.
Interactive 4-section reference guide: conduit type comparison (EMT/IMC/RMC/PVC/FMC/LFMC/ENT), cable assemblies (NM-B/MC/AC/UF/SE/USE), NEC Article 430 motor branch-circuit components, and special equipment/occupancy rules under Articles 440/600/511. First 3 free to preview.
Interactive 27-chapter guide: Ohm's law and circuit fundamentals, utility distribution and substations, service entrance/riser diagrams, panel and load distribution, grounding/bonding/ground-fault protection, and motor circuits, low-voltage Class 1/2/3 circuits, and solar/generator power. First 3 free to preview.
Interactive 19-chapter guide: transmission and grid interconnection (230-500 kV), 13.8 kV distribution feeders and underground loops, hospital/mall/campus facility power systems, solar and flow-battery interconnection, and advanced grid concepts โ HVDC protection, microgrid black start/islanding, and smart-city grids. First 3 free to preview.
Interactive 26-chapter guide built from a complete single-family home electrical drawing set: 400A service and NEC load calculations, panel schedules, floor-by-floor power/lighting/circuit plans, kitchen/HVAC/garage/EV/generator circuits, and voltage drop, surge protection, and commissioning documentation. First 3 free to preview.
Interactive 34-chapter guide built from a real corporate campus drawing set: 13.8kV utility service and MV metal-clad switchgear, building distribution and busway, emergency generator paralleling, panel/feeder schedules, lighting/grounding, short-circuit/arc-flash/harmonic studies, installation details, and SCADA/fire alarm/commissioning documentation. First 3 free to preview.
Interactive 25-chapter guide built from a complete 115/13.8 kV ring bus substation design package: site layout and one-line schemes, protection relay zones and coordination curves, SCADA/RTU architecture, control building and equipment/structural details, and grounding grid, cable trench, foundation, and station backup power design. First 3 free to preview.
Zoomable 62-plate drawing set for an onsite gas-fired power plant serving an AI data center campus: 100 MW critical load on 120 MW N+1 generation, 34.5 kV one-line diagrams with A/B redundant critical feeders, generator/transformer protection and anti-islanding, grounding grid and lightning protection, cable/duct-bank infrastructure, OT networking, and black-start/load-shedding/grid-reconnection sequences. First 3 free to preview.
Interactive 54-chapter illustrated guide: how NEC Article 220 load calculations connect to related articles, service entrance and utility connection basics with clearance requirements, main panel wiring and grounding/bonding fundamentals (ground rods, Ufer grounds, intersystem bonding), residential wiring with smoke/CO alarm placement per NFPA 72/720, renewable integration (off-grid and grid-tied solar/battery systems, wind-generator interconnection), motor circuits (NEC Article 430), load calculations and voltage drop, room-by-room floor plans, working space requirements (NEC 110.26) and symbols legends, and specialty topics like isolated-ground receptacles, bathroom luminaire zones, access control wiring, and generator transfer switches. First 3 free to preview.
Interactive 33-chapter guide built from a companion 115/13.8 kV ring-bus substation design package: site/civil layout (fencing, grading, drainage, oil containment), transformer and breaker foundation engineering, 125 VDC battery/charger and DC alarm systems, protection zoning and SCADA/communications, IEEE 80 grounding grid design, and cable trench/duct bank infrastructure. First 3 free to preview.
A 51-illustration visual reference for NEC 2026 electrical inspection โ one complete, labeled illustration per slide, no filler text. Load calculations and NEC article relationships, voltage system configurations and distribution riser diagrams, conductor sizing and fault-current calculations, wiring methods, grounding/bonding, field testing, standby power and hospital essential systems, special occupancies (pools, elevators, livestock buildings, manufactured homes, marinas, hazardous locations, temporary power), and arc-flash and shock protection boundaries.
Interactive 17-chapter guide built from two real load-addition use cases: a residential 100A-to-200A service upgrade for an all-electric heat pump conversion, and a commercial office building adding a server room and UPS system โ NEC 220 load calculations, service/panel/transformer adequacy checks, feeder and panel schedules, and one-line diagram standards. First 3 free to preview.
Interactive 22-chapter guide of fully worked NEC calculation worksheets: residential and 12-unit multifamily load calculations, conductor ampacity/voltage-drop/motor/feeder/service/grounding-electrode/equipment-grounding/neutral sizing, and OCPD sizing for branch circuits, feeders, services, motors, HVAC equipment, tap conductors, and transformers โ each with real project numbers, plus blank field worksheet forms. First 3 free to preview.
Interactive 22-chapter guide treating electrical and ICT grounding/bonding as one unified system: grounding physics and terminology, NEC-centric electrical grounding (GES, MBJ/SBJ, separately derived systems, conductor sizing, lightning/surge), ANSI/BICSI-607 and TIA-607 style ICT bonding (TMGB/TGB, equalization networks, rack/tray bonding, telecom rooms, DAS/RF, CCTV/access control), field testing, and 5 full facility case studies. First 3 free to preview.
Interactive 26-section field reference of 22 real pass/fail/N/A checklist tables organized into 4 parts: residential (service entrance, panelboards, branch circuits, lighting/receptacles, grounding, final inspection), commercial (distribution, feeders/transformers, wiring methods, emergency/exit lighting, motor/HVAC, fire alarm/low-voltage, final inspection), specialized (grounding/lightning protection, PV/battery/generator, hazardous locations, health care/educational, temporary power), and compliance/documentation โ each row with the exact NEC code reference. First 3 free to preview.
Interactive 15-slide encyclopedia of test and measurement instruments: digital multimeters (True-RMS vs. average-responding), oscilloscopes (bandwidth, sample rate, probe compensation, triggering), spectrum analyzers, signal generators, vector network analyzers with VSWR/return loss, RF power meters, OTDRs, optical power meters, optical spectrum analyzers, logic analyzers, JTAG/SWD debuggers, and Ethernet/RFC 2544 testers โ each with common measurement mistakes, best practices, and related standards. First 3 free to preview.
Zoomable 21-sheet single-family home electrical construction drawing set, captured at print resolution โ one-line diagram, NEC 220.82 service load calculation, panel/feeder schedules, site & floor plans, EV charger circuit diagram, riser diagram, and grounding/bonding details. Sheets 1-3 free to preview.
Zoomable 42-sheet distribution substation design drawing set โ site/civil plans, single-line diagrams, 69kV switchyard, 13.8kV switchgear, grounding & lightning protection, control house, SCADA/RTU, protection & relay schematics, and IEEE 80 grounding calculations. Sheets 1-3 free to preview.
Zoomable 37-image illustrated reference collection โ power distribution fundamentals, grounding & bonding, conductor sizing, NEC article maps, motor/protective device sizing, fire alarm & low-voltage systems, building automation, and a matched substation illustration set. First 4 free to preview.
Zoomable 38-illustration guide โ voltage configurations, a generation-transmission-distribution overview, electrical testing procedures, the Ohm's Law reference wheel, electrical formula sheets and worked calculation examples, load and voltage-drop calculations, cable sizing, three-phase motor star/delta connections and stator winding construction, transformers and automatic voltage regulation, VFD commissioning, transformer protection relaying (differential, Buchholz, earth fault, CT/PT), and single-line diagrams for grid stations and substations. First 5 free to preview.