Question 1
A 3-phase Delta-connected heating load consists of three 20 Ohm resistors. If the line voltage is 600V, what is the total power consumed?
Question 2
A 600V, 3-phase capacitor bank is rated at 50 kVAR. What is the line current?
Question 3
A 600V, 50 kVAR capacitor bank draws how much current?
Question 4
A warehouse is being upgraded to LED high-bay fixtures. The project requires 40 fixtures, each drawing 1.5A at 347V. If the circuits must be loaded to no more than 80%, how many 15A branch circuits are required?
Question 5
An electrician is calculating the service size for a single dwelling with a living area of 150 square meters. Following standard Canadian load calculation concepts (CEC Section 8), what is the basic load for the first 90 square meters?
Question 6
An electrician is sizing a 120V branch circuit for a continuous load of 12A. If the terminals are rated at 75°C and the conductor is NMD90, what is the minimum standard overcurrent device rating required?
Question 7
A 120/240V, 3-wire service has a total calculated load of 28,800 Watts. What is the minimum standard ampacity required for the service conductors?
Question 8
According to Canadian practice for residential load calculations, what is the basic load for the first 90 m² of living area in a single-family dwelling?
Question 9
Calculate the total service demand for a small 400 m² retail store with 40 kW of general lighting, 10 kW of continuous heating, and two 5 HP 208V motors (16.7 A FLA each).
Question 10
An electrician is calculating the service demand for a residence with a total living area of 140 m². According to Canadian load calculation principles, what is the basic load for the first 90 m²?
Question 11
When designing a service for a mixed-use building with both dwelling and commercial spaces, what is a key consideration regarding neutral conductor sizing?
Question 12
A continuous load of 16 A is supplied by a branch circuit. What is the minimum standard rating for the overcurrent protective device, assuming it must be sized at 125 percent of the continuous load?
Question 13
For a small single-family dwelling, which load is typically included in the general lighting load calculation using a VA per square foot method?
Question 14
A 15 A, 120 V branch circuit is supplying three portable loads: 4 A, 3 A, and one additional continuous load. To stay within 80% of the circuit rating for continuous loading, what is the maximum current allowed for the additional continuous load?
Question 15
A lighting branch circuit has a connected load of 12 amperes and is considered continuous. What minimum rating should the overcurrent device have, assuming standard practice of 125 percent for continuous loads?
Question 16
A panel schedule shows a 100-amp, 120/240-volt single-phase service with a calculated load of 72 amps. What percentage of the service rating is being used?
Question 17
An electrician is asked to add a new feeder to an existing service. What is the best first step to ensure the service capacity is adequate?
Question 18
You are asked to calculate conductor size for a feeder with a continuous load of 160 A. Assuming copper conductors and that the code requires sizing at 125% of the continuous load, what is the minimum ampacity required?
Question 19
A continuous load of 16 A will be supplied by a general-purpose branch circuit. What minimum standard breaker size should be selected to comply with the 125% rule for continuous loads?
Question 20
A dwelling load calculation shows 9000 VA of general lighting and receptacle load after applying demand factors, plus 8000 VA of cooking equipment and 5000 VA for a range. What is the total calculated load in VA for sizing the service or feeder?
Question 21
A continuous load of 24 A is supplied by a branch circuit. Using the 125% rule for continuous loads, what is the minimum ampere rating of the overcurrent device?
Question 22
When planning the service for a commercial building, which load is typically considered in determining the minimum service size?
Question 23
You are sizing a service feeder for a small multi-family building. Why is it important to apply demand factors to calculated loads?
Question 24
A feeder is protected by a 100 A breaker. It supplies 70 A of continuous load and 40 A of noncontinuous load. If continuous loads must be multiplied by 125% for feeder sizing, does this feeder meet the requirement?
Question 25
A branch circuit is protected by a 20 A breaker and wired with 12 AWG copper. The connected loads total 14 A continuous and 4 A non-continuous. Is this arrangement acceptable?
Question 26
In a feeder calculation, why is it important to consider both continuous and noncontinuous loads?
Question 27
A 50 A, 240 V single-phase feeder supplies a small workshop subpanel. The measured load after all equipment is running is 30 A. Which statement is most accurate?
Question 28
A continuous load of 16 A is to be supplied by a 120 V branch circuit. What is the minimum standard overcurrent device rating that should be used, based on the 80 percent rule for continuous loads?
Question 29
A dwelling has three 1500 W small-appliance loads that may operate simultaneously on a 120/240 V service. Approximately how much current do these three loads draw at 240 V total, assuming they are evenly distributed?
Question 30
Calculate the power in a 3-phase circuit: Voltage = 480V, Current = 20A, Power Factor = 0.9.