National Electric Code (NEC) Article 240.
Overcurrent protection shall not exceed _____.
15A for 14 AWG copper, 20A for 12 AWG copper, 30A for 10 AWG copper.
Circuit breakers and switches containing fuses shall be readily accessible and installed so the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than _____ above the floor or working platform.
6 ft 7 in.
Conductors supplied under the tap rules are allowed to supply another conductor using the tap rules.
False.
Circuit breakers used to switch 120V and 277V fluorescent lighting circuits shall be listed and marked _____.
SWD or HID.
Supplementary overcurrent devices used in luminaires or appliances are not required to be readily accessible.
True.
Fuses shall be marked with their _____.
ampere and voltage rating, interrupting rating where other than 10,000A, name or trademark of the manufacturer.
Outside feeder tap conductors can be of unlimited length without overcurrent protection at the point they receive their supply if the tap conductors _____.
are protected from physical damage, terminate at a single circuit breaker or a single set of fuses that limits the load to the ampacity of the tap conductors, the overcurrent device is part of the building feeder disconnect.
Plug fuses of the Edison-base type shall be used only _____.
as a replacement in existing installations.
The next higher standard rating overcurrent device above the ampacity of the ungrounded conductors being protected shall be permitted to be used, provided the _____.
conductors being protected are not part of a branch circuit supplying more than one receptacle for cord-and-plug-connected portable loads, ampacity of the conductors does not correspond with the standard ampere rating of a fuse or circuit breaker, next higher standard rating selected does not exceed 800A.
A circuit breaker with a slash rating, such as 120/240V or 480Y/277V, shall be permitted to be applied in a solidly grounded circuit where the nominal voltage of any conductor to ground _____ the lower of the two values of the circuit breaker's voltage rating and the nominal voltage between any two conductors _____ the higher value of the circuit breaker's voltage rating.
does not exceed.
Overcurrent devices are not permitted to be located in the bathrooms of _____.
dwelling units, doritories, guest rooms or guest suits of hotels or motels.
Circuit breaker enclosures shall be permitted to be installed _____ where the circuit breaker is installed in accordance with 240.81
horizontally.
For adjustable-trip circuit breakers, restricted access is defined as _____.
located behind bolted equipment enclosure doors, located behind locked doors accessible only to qualified personnel, password protected, with password accessible only to qualified personnel.
Where the circuit breaker handles are operated vertically, the "up" position of the handle shall be the "_____" position.
on.
Circuit breakers shall _____ all ungrounded conductors of the circuit both manually and automatically unless specifically permitted otherwise.
open.
Overcurrent protection for conductors and equipment is provided to _____ the circuit if the current reaches a value that will cause an excessive or dangerous temperature in conductors or conductor insulation.
open.
Reconditioned circuit breakers shall be listed as âreconditionedâ and the original listing mark shall be _____.
removed.
A circuit breaker with a _____ voltage rating, such as 240V or 480V, can be used where the nominal voltage between any two conductors does not exceed the circuit breaker voltage rating.
straight.
A conductor, other than a service conductor, that has overcurrent protection ahead of its point of supply that exceeds the ampacity permitted for similar conductors is known as a _____.
tap conductor.
When taps are not over 10 ft in length for field installations, and they leave the enclosure or vault in which the tap is made, the ampacity of the tap conductors cannot be less than _____ the rating of the device protecting the feeder.
⅒
