E2 Sizing and Protection of Motor Circuits 2

Question 1

Per NEC 430.22, the minimum ampacity for branch circuit conductors supplying a single continuous-duty motor shall be what percentage of the motor's full-load current?

Accepted Answer

125% of FLA

Answer

100% of FLA

Answer

115% of FLA

Answer

150% of FLA

Question 2

Which NEC table provides full-load current values for single-phase AC motors used for conductor and protection sizing?

Accepted Answer

Table 430.248

Answer

Table 430.247

Answer

Table 430.249

Answer

Table 430.250

Question 3

A 5 HP, 230V, single-phase motor has a table FLA of 28A. What is the minimum required branch circuit conductor ampacity?

Accepted Answer

35A

Answer

28A

Answer

32.2A

Answer

42A

Question 4

Per NEC 430.6(A)(1), which current value is used for sizing motor branch circuit conductors and short-circuit/ground-fault protective devices?

Accepted Answer

Values from Tables 430.247 through 430.250

Answer

Motor nameplate ampere rating

Answer

Locked rotor current rating

Answer

Service factor current

Question 5

A 20 HP, 460V, 3-phase motor has a table FLA of 27A. What is the minimum branch circuit conductor ampacity required by NEC 430.22?

Accepted Answer

33.75A

Answer

27A

Answer

31.1A

Answer

40.5A

Question 6

Which NEC table provides full-load current values for 3-phase AC squirrel cage and synchronous motors?

Accepted Answer

Table 430.250

Answer

Table 430.247

Answer

Table 430.248

Answer

Table 430.249

Question 7

Per NEC Table 430.22(E), motor branch circuit conductors for a 30-minute duty-rated motor must have an ampacity of at least what percentage of the motor's FLA?

Accepted Answer

150%

Answer

110%

Answer

120%

Answer

200%