Deck 29: Service-Entrance Calculations

Question 1

Sizing the neutral conductor only for the normal neutral unbalance current could result in a neutral conductor too ____ to safely carry fault currents.

A) likely to fail
B) large
C) erratic
D) small

Answer 1

D

Question 2

In addition to carrying the unbalanced current, the service neutral conductor must also be capable of safely carrying any ____________________ that it might be called upon to carry.

Answer 2

fault current

Question 3

When calculating the size of the required service, household cooking equipment demand factors are given in Table ____________________.

Answer 3

220.55

Question 4

When there are four or more appliances fastened in place, a demand factor of ____________________ shall be applied to the appliances.

Question 5

Loads, such as heating and air-conditioning, that do not operate at the same time are said to be non-coincident loads. While separate circuits must be designed to serve each load, when calculating service load per NEC 220.60, only the ____________________ of two non-coincident loads need to be included.

Question 6

When calculating the size of the required service, household electric clothes dryer demand factors are given in Table ____________________.

Question 7

A residence is supplied by 2/0 AWG service entrance conductors. Checking Table 250.66, we find that the minimum grounding electrode conductor must be a(n) ____________________ AWG copper conductor.

Question 8

The service neutral conductor may be insulated or bare.

Question 9

In a residential service, the grounded (neutral) conductor is permitted to be smaller than the ungrounded (hot) conductors provided it is sized to handle the neutral load and is not smaller than the ____________________.

Question 10

The grounding electrode conductor is sized according to Table ____________________.

Question 11

The main service disconnecting means in this residence is rated ____ amperes.

A) 50
B) 100
C) 200
D) 250

Question 12

When calculating residential service load, ____ are allowed for each branch circuit serving laundry receptacles.

A) 1,440 watts
B) 1,500 volt-amperes
C) 1,920 watts
D) 2,000 volt-amperes

Question 13

When figuring kitchen load to calculate residential service size, which of the following must be located?

A) 1,500 volt-amperes for each small-appliance branch circuit
B) 180 volt-amperes for each kitchen receptacle not on the small-appliance circuits (refrigerator, gas range, clock, etc.)
C) 100 volt-amperes for lighting
D) none of these

Question 14

Where raceways are installed in wet locations above grade, the interior of these raceways shall be considered to be a wet location.

Question 15

It is not within the realm of local authorities to publish code requirements specifically for their communities.

Question 16

A rather recent innovation for residential metering is "____" metering, also referred to as "real-time" or "smart" metering.

A) reality based
B) smart-time
C) actual
D) time-based

Question 17

Table ____________________ may only be used for 120/240-volt, 3-wire, residential single-phase service-entrance conductors, underground service conductors, and feeder conductors that serve as the main power feeder to a dwelling unit.