Lineman Safety and Technical Skills 3 — Questions and Answers
Question 1: What is the purpose of a load buster tool when used on cutout fuses?
- To test continuity across the fuse element
- To safely open or close a cutout under load without arcing damage to the operator (Correct answer)
- To measure the load current before switching
- To clamp the fuse holder in place during replacement
Correct answer: To safely open or close a cutout under load without arcing damage to the operator
A load buster (or fuse puller with arc quenching) allows linemen to open or close cutouts energized under load while safely extinguishing the resulting arc.
Question 2: In a three-phase system, if one phase conductor is open (broken), what is this condition called?
- Phase reversal
- Single phasing (Correct answer)
- Ground fault
- Overload condition
Correct answer: Single phasing
Single phasing occurs when one of the three phases is lost, which can cause motors to overheat and fail due to unbalanced current in the remaining phases.
Question 3: When using a hydraulic digger derrick, the maximum allowable boom angle from horizontal during lifting operations is typically?
- 45 degrees
- 70 degrees
- 80 degrees
- Specified by the manufacturer's load chart (Correct answer)
Correct answer: Specified by the manufacturer's load chart
Maximum boom angle and load capacity must always be determined from the specific manufacturer's load chart, as they vary by equipment model.
Question 4: A lineman is making a dead-end splice on an ACSR conductor. What is the correct sequence for installing a compression sleeve?
- Compress from center outward in both directions
- Compress from one end straight through to the other end
- Compress the steel core first, then the aluminum sleeve from the conductor end toward the dead-end (Correct answer)
- Compress randomly to distribute the load evenly
Correct answer: Compress the steel core first, then the aluminum sleeve from the conductor end toward the dead-end
For ACSR dead-end compression connectors, the steel core insert is compressed first, then the aluminum sleeve is compressed starting from the conductor end and working toward the dead-end fitting.
Question 5: What is the function of a recloser on a distribution line?
- To measure power quality and log voltage sags
- To automatically interrupt and reclose the circuit after a fault, restoring service if the fault is temporary (Correct answer)
- To limit current during motor starts
- To balance load between phases automatically
Correct answer: To automatically interrupt and reclose the circuit after a fault, restoring service if the fault is temporary
A recloser automatically opens on fault current and attempts to reclose the circuit one or more times, restoring service if a temporary fault (like a tree limb) has cleared.
Question 6: What is the correct procedure for testing rubber insulating gloves before each use in the field?
- Inflate each glove by rolling the cuff and checking for air leaks, then visually inspect for cracks or pinholes (Correct answer)
- Soak in water for 10 minutes and look for bubbles
- Test with a multi-meter for resistance
- Hold up to sunlight and look for thin spots only
Correct answer: Inflate each glove by rolling the cuff and checking for air leaks, then visually inspect for cracks or pinholes
Rubber insulating gloves must be inflated (air test) by rolling the cuff or using a glove inflator, then visually inspected for ozone damage, cuts, or punctures before each use.
Question 7: On a padmounted transformer, which color typically identifies the H-side (primary) bushings in the US?
- Blue
- Black (Correct answer)
- Yellow
- Red
Correct answer: Black
In US convention, H-side (high-voltage primary) bushings on padmounted transformers are typically black, while X-side (secondary) bushings are yellow.
Lineman Safety and Technical Skills 3
What is the purpose of a load buster tool when used on cutout fuses?