Calculations for Dwelling Units

Question 1

Table 220.42 demand factors for dwelling units

Answer 1

First 3000va at 100%
From 3001 to 120000 at 35%
Remainder over 120000 at 25%

Question 2

A demand factor of ___% can be applied to appliances that are fastened in place

Answer 2

75

Question 3

The calculated load for a dryer must be ___va or nameplate, whichever is higher

Answer 3

5000

Question 4

Service conductors supplying a single dwelling unit may have its ampacity sized to ___% of the service overcurrent device rating

Answer 4

83

Question 5

The neutral load for household cooking equipment is considered ___% of the calculated load

Answer 5

70

Question 6

The demand factors for general loads for the optional method are

Answer 6

The first 10kVA at 100%

The remainder at 40%

Question 7

When using the optional method for a dwelling unit service calculation, the only connected load not subject to the demand factors are the ___

Answer 7

Heat/AC loads

Question 8

The smallest allowable service size for a dwelling unit

Answer 8

100a

Question 9

An example of linear lighting load

Answer 9

Incandescent

Question 10

Sections

Taps for Branch Ckts
Taps for feeders

Answer 10

210. 19

240. 21

Question 11

Heat/AC for optional method

A/C ___
Heat ___
3 or less heat ___
4 or more heat ___

Answer 11

100%
65%
65%
40%

Question 12

Lighting ckt capacity equations

Noncontinuous loads
Continuous loads

Answer 12

OCPD x Volts = Va capacity

OCPD x Volts x 80% = Va capacity

Question 13

The minimum va for a mobile home lot

Answer 13

16000va

Question 14

Table - demand factors for mobile homes

Answer 14

550.31

Question 15

Areas where lighting are not considered continuous

Answer 15

Dwelling units

Motel rooms

Question 16

For a service over 200a, these demand factors can be applied to the neutral

Answer 16

1st 200a at 100%

Remainder at 70%

Nonlinear loads at 100%

Question 17

For a 3 phase service, when converting from va or wattage to amps, a factor of ___ must be applied to the voltage

Answer 17

1.732

Question 18

For a multi-family dwelling with laundry on premises, the laundry circuit becomes the ___, and can be reduced by what demand factors

Answer 18

Houseload

None

Question 19

For a multi-family optional method calculation, the table for demand factors is

Answer 19

220.84

Question 20

For a multi-family optional method calculation, heat and a/c is calculated

Answer 20

100% of A/C

100% of Heat

Question 21

When calculating a duplex service size, the smaller of ___ shall be permitted

Answer 21

The standard method of the two dwelling units

The optional method per 220.84 of 3 identical units

Question 22

Per Art ___, the largest motor in HP shall have ___% added to the final demand load

Answer 22

220.50

25%