CEA Tools, Equipment & Testing Procedures 3 — Questions and Answers
Question 1: What does a low resistance reading (near zero ohms) between the hot and neutral terminals of a receptacle most likely indicate?
- Correct wiring with good contact
- A short circuit or wiring fault (Correct answer)
- High load on the circuit
- A properly functioning GFCI receptacle
Correct answer: A short circuit or wiring fault
Near-zero resistance between hot and neutral (with power off) indicates a short circuit that must be located and corrected.
Question 2: A lineman's pliers (side-cutting pliers) are primarily designed for:
- Stripping insulation from small gauge wire
- Gripping, twisting, and cutting larger conductors (Correct answer)
- Bending EMT conduit at precise angles
- Measuring wire diameter with a gauge
Correct answer: Gripping, twisting, and cutting larger conductors
Lineman's pliers combine strong jaws for gripping and twisting wire with a cutting edge for heavier conductors.
Question 3: When performing a ground resistance test with a three-point fall-of-potential method, the potential probe should be placed at approximately what distance between the ground electrode and the current probe?
- 10% of the spacing
- 62% of the spacing (Correct answer)
- The midpoint (50%)
- At the same location as the current probe
Correct answer: 62% of the spacing
The 62% rule positions the potential probe in the flat portion of the resistance curve, giving an accurate ground resistance reading.
Question 4: An insulation resistance tester (megohmmeter) reads 'OL' or infinity when testing a motor winding. This indicates:
- A shorted winding with zero resistance
- Good insulation with no leakage path detected (Correct answer)
- The meter range is set too low
- The motor is energized and the reading is invalid
Correct answer: Good insulation with no leakage path detected
An infinity or OL reading on a megohmmeter indicates very high insulation resistance, meaning the insulation is in good condition.
Question 5: Which screwdriver tip type is required for the tamper-resistant screws commonly found on electrical panel covers?
- Standard slotted
- Torx or hex (security bit) (Correct answer)
- Phillips #2
- Cabinet tip (flat with wide blade)
Correct answer: Torx or hex (security bit)
Tamper-resistant screws use Torx, hex, or other security bit profiles to discourage unauthorized access to electrical panels.
Question 6: A non-contact voltage tester (tick tracer) gives a false indication when held near a cable. What is the most common cause?
- The battery in the tester is fully charged
- Induced voltage from an adjacent energized conductor (Correct answer)
- The wire gauge is too small to detect
- The tester only works on AC above 480V
Correct answer: Induced voltage from an adjacent energized conductor
Non-contact testers detect electric fields and can respond to induced voltage from nearby energized conductors, giving a false positive.
Question 7: What is the correct procedure before using a voltage tester at the start of a job?
- Verify the tester operates on a known live source, then test the dead circuit (Correct answer)
- Test the dead circuit first, then check a live source
- Replace the battery regardless of indicator status
- Set the range to the highest voltage and begin testing
Correct answer: Verify the tester operates on a known live source, then test the dead circuit
Always verify the tester works on a confirmed live source before and after testing a de-energized circuit to ensure the tester itself is functional.
CEA Tools, Equipment & Testing Procedures 3
What does a low resistance reading (near zero ohms) between the hot and neutral terminals of a receptacle most likely indicate?