Standards changes, exam-relevant deep dives, and practical field guidance — grounded in the same NFPA 70E citations used throughout ArcReady's study guide and question bank.
Ohm's Law and the Power Wheel, One Formula at a Time
E=IR is only a quarter of the picture. Add power to the mix and you get a four-variable "wheel" where knowing any two values solves for the other two — here's how to actually use it, worked example included.
Read more →Grounding vs. Bonding vs. GFCI: Three Different Jobs
Grounding, bonding, and GFCI protection get treated as interchangeable, but they do three different jobs. Here's what each one actually protects against — including the specific fault a GFCI can't see coming.
Read more →The ASTM/ANSI Standards Behind Your PPE
Two face shields can look identical and protect against completely different hazards. Here's the standard-by-standard breakdown of what your PPE actually has to be certified against — and why the label matters more than the look of the gear.
Read more →Special Operating Conditions: What Actually Counts
A 600V panel sounds like a special hazard, but voltage alone doesn't make a location "special" under NFPA 70E. Here's what actually triggers the extra precautions — and the one meter mistake that can turn a classified area into an ignition risk.
Read more →The Energized Work Permit: When, Why, and Who Signs
Energized work is the exception, not a shortcut — and it takes two signatures to authorize it. Here's exactly when a permit is required, who has to sign it, and what it must document.
Read more →How to Read an Arc Flash Label, Field by Field
An arc flash label has seven required fields, and two of them look similar enough to mix up under pressure. Here's what each one means and why the incident energy value and the PPE rating aren't interchangeable.
Read more →Establishing an Electrically Safe Work Area: The Steps People Skip
Lockout/tagout isolates the power. It doesn't prove the equipment is actually dead. Here are the verification steps that trip people up most on the exam - and on the job.
Read more →ELI the ICE Man: Making Sense of Phase Shift in AC Circuits
Inductors and capacitors don't just resist current like a resistor does - they shift voltage and current out of sync with each other, in opposite directions. One old mnemonic keeps the two straight for good.
Read more →PPE Is Your Last Resort, Not Your First
A Job Hazard Analysis isn't a form you fill out after deciding what PPE to wear. It's supposed to work through five other options before PPE even enters the conversation.
Read more →NFPA 70E PPE Categories 0-4, Decoded
Five categories, one incident-energy number deciding which one applies, and a hard ceiling above 40 cal/cm² where the tables simply stop answering the question.
Read more →Reading a Multimeter Like a Detective: Open vs. Short Circuit Signatures
An open and a short leave opposite fingerprints in voltage and resistance. Once you know what each one looks like, tracing a fault stops being guesswork.
Read more →The Eight Steps of LOTOTO (It's Not Just Lock and Tag)
Lockout/Tagout/Tryout is eight ordered steps, not two. Most of the ways it goes wrong happen well before anyone touches a padlock.
Read more →Why 120 Volts Kills: The Physiology of Electrical Shock
120V sounds mild next to a 480V panel. It isn't. A little Ohm's Law and a look at how current - not voltage - affects the human body explains why the "low voltage" outlet in your wall can be just as lethal as the big equipment.
Read more →Four Boundaries, One Panel: Making Sense of NFPA 70E's Approach Distances
Limited, Restricted, Arc Flash Protection, and the equipment itself - four zones around every energized panel, each with a different rule for who can be there and what they need to be wearing.
Read more →Wye vs. Delta: The Three-Phase Question That Trips Up the Exam
Two ways to wire three-phase power, two different relationships between line and phase voltage, and one formula - √3 - that shows up so often it's worth memorizing on its own.
Read more →The 15-Second Glove Check That Prevents Fatalities
Rubber insulating gloves are the main thing standing between a qualified worker's hands and a lethal shock. The air inflation test that verifies they're intact takes about 15 seconds - and skipping it is more common than it should be.
Read more →What Actually Happens Inside an Arc Flash
An arc flash isn't a fire and it isn't a shock. It's a plasma explosion that can hit four times the surface temperature of the sun in microseconds - and the number that decides how bad it is has nothing to do with voltage alone.
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