NWSA Electrical Safety and Grounding 3 — Questions and Answers
Question 1: After applying lockout/tagout (LOTO), a worker must verify de-energization by:
- Checking the circuit breaker handle position only
- Asking a coworker to confirm the power is off
- Waiting 30 minutes after the disconnect is opened
- Testing with a properly rated voltage-detecting instrument (Correct answer)
Correct answer: Testing with a properly rated voltage-detecting instrument
LOTO alone is insufficient; the worker must use a calibrated voltage tester to confirm the circuit is de-energized before starting work.
Question 2: Double-insulated power tools are designed to eliminate the need for:
- An equipment grounding conductor, using two independent insulating layers instead (Correct answer)
- GFCI protection in all wet or damp locations
- Pre-use inspection before every work shift
- Any form of overcurrent protection
Correct answer: An equipment grounding conductor, using two independent insulating layers instead
Double-insulated tools use two separate insulation layers so a single failure cannot expose the user to a live conductor, making a ground wire unnecessary.
Question 3: Electrical burns differ from ordinary thermal burns in that they:
- Are always visible and clearly defined on the skin surface
- Can cause severe internal tissue damage along the current's path through the body (Correct answer)
- Heal significantly faster than flame-caused burns
- Only affect the outermost layers of skin
Correct answer: Can cause severe internal tissue damage along the current's path through the body
Electrical current travels through the body and can destroy deep muscle, nerve, and organ tissue in ways that may not be visible from the entry and exit wounds.
Question 4: The NEC requires communication towers to use which type of grounding electrode system?
- A single 8-foot copper-clad rod, which is always sufficient by itself
- Grounding is optional for towers shorter than 150 feet
- An interconnected grounding electrode system (Correct answer)
- Only metallic water pipes are acceptable as electrodes
Correct answer: An interconnected grounding electrode system
The NEC requires communication towers to be connected to an interconnected grounding electrode system for reliable lightning protection and fault current dissipation.
Question 5: Under OSHA regulations, a qualified electrical worker is defined as someone who:
- Holds a four-year electrical engineering degree
- Has at least 10 years of documented field experience
- Is licensed as a journeyman or master electrician in their state
- Has received training and demonstrated ability to work safely on electrical systems (Correct answer)
Correct answer: Has received training and demonstrated ability to work safely on electrical systems
OSHA defines a qualified electrical worker by their training and demonstrated competency to identify and safely manage electrical hazards, not by a specific credential or years.
Question 6: An arc flash hazard analysis is performed to determine:
- Required PPE categories and safe working distances for energized electrical work (Correct answer)
- Optimal antenna placement for maximum RF coverage
- Tower structural load limits under high-wind conditions
- Acceptable grounding electrode resistance thresholds
Correct answer: Required PPE categories and safe working distances for energized electrical work
An arc flash hazard analysis calculates incident energy levels and establishes the required PPE category and safe boundary distances for personnel near energized equipment.
NWSA Electrical Safety and Grounding 3
After applying lockout/tagout (LOTO), a worker must verify de-energization by: