ASVAB CampElectrical Safety and Troubleshooting flashcards
8 cards with the formulas, rules and traps from this lesson. Answer in your head, then flip to check.
Fact · 1/8
What mainly determines how harmful an electric shock is?
The current through the body, its path (hand to hand or hand to feet crosses the chest) and its duration. Voltage is the push; a few tens of milliamperes can be dangerous.
Term · 2/8
What does a GFCI detect, and at roughly what level does it trip?
It compares current leaving on the hot with current returning on the neutral and trips when they differ by about 4 to 6 mA. It cannot sense a hot-to-neutral path through a person.
Rule · 3/8
Match each device to its hazard: fuse or breaker, GFCI, AFCI.
Fuse or breaker: overcurrent (overload or short) to protect wiring. GFCI: current leaking to ground, protecting people from shock. AFCI: dangerous arcing, mainly to prevent fires.
Common trap · 4/8
Does a fuse or circuit breaker protect a person from shock?
No. They respond to amperes of overcurrent, while milliamperes through a body can injure. Shock protection comes from GFCIs, sound insulation and grounding.
Term · 5/8
Overload versus short circuit?
Overload: correctly wired loads draw moderately more than the rating, and heat builds gradually. Short: an unintended low-resistance path lets current jump to many times normal almost instantly.
Formula · 6/8
Why does heating rise so fast with current in a wire or loose joint?
(watts, amperes, ohms). Tripling current gives 9 times the heat; 10 A through a 0.2 joint releases 20 W in one spot, yet the breaker may not trip.
Formula · 7/8
Energy stored in a charged capacitor?
: E in joules, C in farads, V in volts. Tripling voltage stores 9 times the energy; 2,000 F at 100 V holds 10 J even when unplugged.
Term · 8/8
Neutral versus equipment grounding conductor?
The neutral carries normal return current as part of the working circuit. The grounding conductor (bare or green) normally carries no current and only provides a fault path that helps the breaker trip.