OverCurrent Protection Article 240

240.51 Edison-Base Fuses.

(A) Classification. Plug fuses of the Edison-base type shall be classified at not over 125 volts and 30 amperes and below. (B) Replacement Only. Plug fuses of the Edison-base type shall be used only for replacements in existing installations where there is no evidence of overfusing or tampering.

240.50 General.

(A) Maximum Voltage. Plug fuses shall be permitted to be used in the following circuits: (1)Circuits not exceeding 125 volts between conductors (2)Circuits supplied by a system having a grounded neutral point where the line-to-neutral voltage does not exceed 150 volts

240.53 Type S Fuses.

(B) Noninterchangeable. Type S fuses of an ampere classification as specified in 240.53(A) shall not be interchangeable with a lower ampere classification. They shall be designed so that they cannot be used in any fuseholder other than a Type S fuseholder or a fuseholder with a Type S adapter inserted.

240.22 Grounded Conductor.

(1) The overcurrent device opens all conductors of the circuit, including the grounded conductor, and is designed so that no pole can operate independently.

Question Overcurrent protection for a 10AWG copper conductors must not exceed ______:

15A 20A 25A 30A NEC Code 240.4(D)(7)

Household Ranges and Cooking Appliances.

210.19(C) Branch-circuit conductors supplying household ranges, wall-mounted ovens, counter-mounted cooking units, and other household cooking appliances shall have an ampacity not less than the rating of the branch circuit and not less than the maximum load to be served. For ranges of 83⁄4 kW or more rating, the minimum branch-circuit rating shall be 40 amperes.

Question The length of the transformer secondary conductors shall not exceed ____ for conductor from short circuit and ground fault protection:

100 feet 30 feet

Ungrounded Conductors.

240.15

Grounded Conductor.

240.22

what article is Overcuurent Protection

Article 240

Question: When a circuit breaker is utilized without an instantaneous trip, which one of the following or approved equivalent means shall be provided:

Both Zone Selection Interlock and Differential Relay Zone Selection Interlock Differential Relay 240.87 (B)

240.60 General.

Cartridge fuses and fuseholders of the 300-volt type shall be permitted to be used in the following circuits:

Question A Series rated system of protective devices (Combination of fuses and Circuit Breakers) that are applied at ___ side of the circuit having short circuit level above the interrupting capacity:

Either Line side or Load Side Line Side Load Side NEC Code 240.86

Question Series rating of combination of protective devices shall not be used where the motors are connected on ____ side of the higher overcurrent device:

Either Load Side or Line Side Load Side Line Side NEC Code 240.86(C)

Fixture Wire. 240.5 B 2

Fixture wire shall be permitted to be tapped to the branch-circuit conductor of a branch circuit in accordance with the following: (1) 15- or 20-ampere circuits — 18 AWG, up to 15 m (50 ft) of run length (2) 15- or 20-ampere circuits — 16 AWG, up to 30 m (100 ft) of run length (3) 20-ampere circuits — 14 AWG and larger (4) 30-ampere circuits — 14 AWG and larger (5) 40-ampere circuits — 12 AWG and larger (6) 50-ampere circuits — 12 AWG and larger

240.52 Edison-Base Fuseholders.

Fuseholders of the Edison-base type shall be installed only where they are made to accept Type S fuses by the use of adapters.

Question Series rated systems can consist of:

Fuses that protect Circuit Breakers Circuit Breakers that protect the Circuit Breakers Both the options are Correct NEC Code 240.86

240.13

Ground-Fault Protection of Equipment.

Question Circuit breakers used as switches in high-intensity discharge lighting circuits shall be listed and shall be marked as:

HID high-intensity discharge SWD HWD SWP NEC Code 240.83(D)

Question: Series rating of combination of protective devices shall not be used where the motors are connected on ____ side of the higher overcurrent device:

Line Side Load Side Either Load Side or Line Side NEC Code 240.86(C)

240.5

Protection of Flexible Cords, Flexible Cables, and Fixture Wires.

Table 240.6(A)

Standard Ampere Ratings for Fuses and Inverse Time Circuit BreakersStandard Ampere Ratings

240.6

Standard Ampere Ratings.

240.21(B)(1)

Taps Not over 3 m (10 ft) Long. a. Not less than the combined calculated loads on the circuits supplied by the tap conductors

Screw Shell.

The screw shell of a plug-type fuseholder shall be connected to the load side of the circuit.

Question The interrupting rating shall not be required to be marked on circuit breakers used for supplementary protection True

True False NEC Code 240.83(C)