Name That Code

Current Formula I = P/E I = 150 watts x 15/120 volts = 18.75 amperes

A 120-volt branch-circuit is to serve only fifteen, 150 watt incandescent luminaires, and the full-load current in the circuit will be 18.75 amperes.

Current formula I = P/EI = 10KW x 1,000/240 volts = 41.6 amperes

A 240-volt, single-phase, 10KW rated commercial dishwasher has a full-load current rating of 42 amperes.

314.16 (A)

A 4 inch X 1 1/2 inch metal octagon box with a flat blank cover may contain a MAXIMUM of seven size 14 AWG conductors.

240.6 (A)

A 75-ampere circuit breaker is NOT a standard ampere rating listed in the NEC.

430.6 (A) (1), Table 430.248, 430.22 (A) FLC of 7 1/2 HP motor = 40 amperes X 125% = 50 amperes

A branch-circuit supplying a 7 1/2 HP, 240-volt, single-phase induction type, continuous-duty, Design B AC motor shall have an ampacity of at least 50 amperes.

Article 100, 200.6 (A) & (B)

A neutral conductor is a conductor that is intended to carry current under normal conditions.

General Knowledge

A watt is a unit of electrical power.

240.51 (B), 240.60 (D)

Edison-base fuses and Class H renewable cartridge fuses if any, shall be used for replacement only in existing installations and not permitted for use in new installations.

Article 100

Electrical wiring installed under canopies or roofed open porches is considered to be installed in a damp location.

Trade Knowledge

If the voltage-drop of a branch-circuit is too great, it may result in unsatisfactory illumination of lighting fixtures, or overheating of a motor or unsatisfactory motor speed.

404.8 (A)

In general, all switches and circuit breakers used as switches shall be located so that they may be operated from a readily accessible place. They shall be installed so that the center of the grip of the operating handle of the switch or circuit breaker, when at its highest position is NOT more than 6 feet, 7 inches above the floor or platform.

362.30 (A)

In general, electical nonmetallic tubing (ENT) shall be securely fastened at intervals not exceeding 3 feet.

310.3

In general, the NEC mandates the largest size insulated solid conductor permitted to be installed into an existing raceway is 10 AWG.

210.21 (B) (1)

In general, when a 20-ampere rated branch-circuit supplies a single receptacle outlet, the rating of the receptacle must not be less than 20 amperes.

Article 100

That portion of a wiring system that is between the final overcurrent device protecting the circuit and the outlets is defined as a branch-circuit.

110.26 (E)

The MINIMUM required distance from the floor to the ceiling in front of a 400-ampere rated motor control center disconnect switch, or main switchboard is 6 feet, 6 inches.

Article 100

The NEC mandates specific branch-circuits, receptacle outlets, and utilization equipment to be provided with a ground-fault circuit interrupter (GFCI); this device is intended for the protection of personnel.

90.1 (B) & (C)

The National Electrical Code is (NEC) NOT designed for future expansion of electrical use.

Article 100

The ampacity of a conductor is defined by the NEC to be the curren in amperesk, a conductor can carry continuously under the conditions of use without exceeding its temperature rating.

Table 430.248

The full-load running current of a 3-HP, 208-volt, single phase, continuous duty AC motor is 18.7 amperes.

210.8 (B) (4)

When a 20-ampere, 120-volt receptacle outlet is installed under an outdoor canapy, near the entrance of a public library, is required to have GFCI protection.

408.36 (A)

When a 225-ampere rated panelboard contains only twenty snap switches (circuit breakers) rated at 30 amperes each, the panelboard shall have overcurrent protection not in excess of 200 amperes.

Trade Knowledge

When checking for continuity between a circuit breaker and the neutral bar of a panelboar when using a continuity tester, positive continuity is indicated because a conductor may be grounded, or a luminaire or an appliance may be turned on.

358.26

When installin electrical metallic tubing (EMT), there shall be no more than four 90* bends in the tubin between boxes and/or pull points.

Table 310.16

Where the copper conductors supplying the previous referenced motor will have a temperature rating of 75*C, the MINIMUM size as required by the NEC is 8 AWG.