Question 1
On a typical residential floor plan, which symbol usually represents a ceiling-mounted light outlet?
Question 2
A motor nameplate indicates 230 V, 10 A, single-phase. Approximately what size overcurrent device might be chosen if motor protection is based on 125% of nameplate current, ignoring other code factors?
Question 3
During an infrared inspection of a distribution panel, you observe one breaker terminal significantly hotter than others on the same phase. The load currents are similar. What is the most probable cause?
Question 4
A feeder panel is fed from a main service. When balancing loads on a three-phase panel, what is the main objective?
Question 5
You are asked to verify the load calculation for a small commercial service. The calculated demand load is 96 kVA at 120/208 V, 3-phase. What is the approximate full-load current per phase at this demand?
Question 6
Before energizing a new service, which sequence is most appropriate?
Question 7
In a 600/347 V three-phase, four-wire wye system commonly used in Canadian commercial buildings, what is the nominal line-to-neutral voltage?
Question 8
What is the main hazard associated with opening the secondary circuit of an energized current transformer (CT)?
Question 9
What is the primary difference between a 'current transformer' (CT) and a standard 'potential transformer' (PT) in power distribution?
Question 10
What is the primary function of a 'Current Transformer' (CT) in a high-current service entrance?
Question 11
What is the primary difference between a 'current transformer' (CT) and a 'potential transformer' (PT) in power distribution?
Question 12
What is the primary difference between a 'current transformer' (CT) and a 'potential transformer' (PT) in power distribution metering?
Question 13
A motor nameplate shows 7.5 kW at 230 V, single-phase, with a full-load current (FLC) of 40 A. What is the MOST appropriate overcurrent device size if the code permits up to 125% of FLC for overcurrent protection?
Question 14
Several single-phase receptacle circuits in a commercial panel are tripping during peak usage. Loads are primarily resistive and evenly distributed. Which action is the best first step in addressing this issue?
Question 15
A feeder has a calculated noncontinuous load of 80 A and a continuous load of 40 A. What is the minimum ampacity that should be used for the feeder conductors when applying the 125% factor to the continuous load?
Question 16
A feeder calculation for a small commercial panel shows a demand load of 96 A at 208/120 V three-phase. What is the minimum standard size breaker likely to be selected for this feeder (assuming 125% factor is not required)?
Question 17
A homeowner reports that half the receptacles on one circuit have stopped working, but the breaker is not tripped and other devices on the same breaker still work. Which is the MOST likely cause?
Question 18
A 60 A feeder at 240 V serves a small panel. If the calculated load on that feeder is 40 A, what is the approximate percentage loading of the feeder?
Question 19
An apprentice finds a receptacle that feels warm to the touch under load, but the breaker is not tripping. What is the MOST likely cause?
Question 20
Which of the following conditions requires that a portable power tool be removed from service?
Question 21
In a 120/240 V single-phase dwelling, occupants report that some lights get brighter while others get dimmer when a large 240 V range is turned on. No breakers are tripping. Which service problem is most likely?
Question 22
A 120/240 V single-phase service has a main breaker rated at 150 A. If the calculated dwelling load is 120 A, what does this indicate?
Question 23
What is the primary purpose of a **Current Transformer** (CT) in a high-voltage metering application?
Question 24
A journeyperson uses a **hydraulic bender** to make a large radius $90$-degree bend in $4$-inch Rigid Galvanized Steel (RGS) conduit. What is the most critical safety precaution specific to this tool?
Question 25
What is the primary danger of opening the secondary circuit of an energized current transformer (CT)?
Question 26
A Current Transformer (CT) has a ratio of 400:5. If 200A flows in the primary, what is the secondary current?
Question 27
What is the primary danger associated with opening the secondary circuit of an energized Current Transformer (CT)?
Question 28
What is the primary danger of working on a current transformer (CT) circuit while it is energized?
Question 29
What is the primary function of a CT (Current Transformer) in a service metering installation?