Deck 4: Services and Feeder Calculations

Question 1

It is common in commercial buildings for the load to operate mostly at the higher voltage and not utilize the ___________________.

Answer 1

neutral conductor

Question 2

A disconnecting means inside a building should not be installed near the point where supply conductors enter the building.

Answer 2

False

Question 3

A disconnect is permitted to be located outside and off the actual building as long as it is readily accessible.

Answer 3

True

Question 4

With respect to the calculations of current as compared to the previous editions of the Code, it is permitted to round fractions down to the next lower whole ampere if less than ___________________ ampere(s).

Question 5

In general, how is total load subdivided?

Question 6

How is motor load calculated for three-phase motors?

Question 7

A duplex receptacle represents a load of ____________________ VA.

Question 8

[(Average range rating - 12) x 0.05(Value from column C of Table 220.55)] +(Value from column C of Table 220.55) = ____________________

Question 9

A store has an area of 357.8 m².This store has a continuous load of 12,544VA, a noncontinuous load of 16,000VA, and a motor load of 5000VA.What is the total load for the store?

Question 10

Which Article provides the minimum requirements for feeder conductor size and overcurrent protection?

Question 11

When determining the average, all electric ranges rated greater than 8 3/4 kW but not greater than 12 kW are to be taken as though they were rated at ___________________ kW.

Question 12

The maximum unbalanced load for a service is the maximum load that can be expected on the neutral conductor.

Question 13

Determine the load in volt-amperes for a 10-horsepower, 300-volt, single phase electric motor to be used in a feeder calculation.Hint: assume that the full load current of the motor is 30.8 amperes.

Question 14

In the case of a circuit breaker used as a disconnect, the maximum rating is the minimum continuous current setting of the circuit breaker.

Question 15

Feeders are main conductors that are ultimately subdivided into smaller circuits.

Question 16

In general, what does the load for receptacles on 15- and 20-ampere, 125-volt general circuits depend upon?

Question 17

A multifamily dwelling unit has 25 units: eight with 11kW electric ranges, two with 9kW electric ranges, and fifteen with 14 kW electric ranges.Determine the average rating range for the 25 living units.

Question 18

Noncontinuous loads generally operate for less than ____________________ hours.

Question 19

Identifying all of the loads that operate at the lower voltage and that would use the neutral is the method for determining the ____________________.

Question 20

Equipment ground-fault protection can sometimes be avoided by using multiple disconnects each rated less than ____________________ amperes.