ISA Certified Arborist Utility Specialist — Practice Exam
Electrical knowledge: practice questions
Our ISA Utility Specialist bank has 79 questions on this topic. Here are 5 of them with answers; the full mock exam draws from every topic, like the real one.
Question 1
How does 1910.269 define 'energized'?
- Connected to a source of potential difference, or charged to a potential significantly different from earth
- Carrying current to a customer at that moment
- Carrying current to at least one customer at that moment, as shown by the meter reading
- Marked with a warning sign
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A. Connected to a source of potential difference, or charged to a potential significantly different from earth — Deenergized means free from any connection to a source of potential difference and from electric charge.
Question 2
Per OSHA's eTool, when may line-clearance tree trimmers work in any weather?
- Never in any weather
- Whenever wearing rubber boots
- Whenever they wear rubber boots and insulating gloves rated for the voltage of the line
- When the lines and circuits are deenergized under 1910.269(m)
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D. When the lines and circuits are deenergized under 1910.269(m) — Otherwise adverse weather that makes the work hazardous stops it.
Question 3
What did the FERC-commissioned report find caused the faults on the lines investigated after the August 2003 blackout?
- Overgrown trees, not excessive conductor sag
- Squirrels in substations
- Lightning strikes on four 345 kV lines during the afternoon storms
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A. Overgrown trees, not excessive conductor sag — Had the trees been pruned or removed, the blackout would likely not have occurred.
Question 4
How does 1910.269 Appendix C describe touch potential?
- The voltage between two phases
- The voltage a glove is rated for
- The voltage between an energized grounded object and the feet of a person touching it
- The voltage between two phase conductors measured at the same pole
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C. The voltage between an energized grounded object and the feet of a person touching it — It can be nearly the full fault voltage if the object is grounded far from where it is touched.
Question 5
What does CAIDI measure?
- How often the average customer loses power during a year
- Total customer minutes per year
- The average number of minutes it takes to restore service after an interruption
- How many times the average customer lost power during the year, counting only sustained events
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C. The average number of minutes it takes to restore service after an interruption — Dividing SAIDI (minutes per customer) by SAIFI (interruptions per customer) gives minutes per interruption.