PROVISIONS FOR ELECTRICAL SYSTEM DESIGN 2

Question 1

This article provides requirements for the identification of terminals, grounded conductors in premises wiring system, and identification of grounded conductors.

Answer 1

Article 2.0 Use and Identification of Grounded Conductors

Question 2

This article provides the general requirements for branch circuits.

Answer 2

Article 2.10 Branch Circuits

Question 3

In dwelling units and guest rooms or guest suites of hotel, motels and similar occupancies, the voltage shall no exceed _________, between conductors that supply (1) luminaires (s) chord-and-plug connected loads 2760 volt amperes, nominal, or less or less than ½ hp.

Answer 3

230 V nominal

Question 4

Multi-outlet branch circuits greater than _____ shall be permitted to supply non lighting outlet loads on industrial premises where conditions of maintenance and supervision ensure that only qualified persons service the equipment.

Answer 4

50 A

Question 5

For ranges of 8 ¾ kW rating, the minimum branch circuit rating shall be _____.

Answer 5

40 A

Question 6

Where a branch circuit supplies continuous loads or any combination of continuous and non continuous loads, the rating of the overcurrent protective device shall not be less than the noncontinuous loads plus _____ of the continuous loads.

Answer 6

125%

Question 7

The rating of any cord-and-plug-connected utilization equipment not fastened in place not exceed _____ of the branch-circuit ampere rating.

Answer 7

80%

Question 8

A ________ branch circuit shall be permitted to supply lighting units or other utilization equipment, or a combination of both

Answer 8

15- or 20 A

Question 9

A ________ branch circuit shall be permitted to supply fixed Lighting Units with Heavy-Lamp holder other than Utilization Equipment.

Answer 9

30 A

Question 10

A _____ branch circuit shall only supply non-lighting outlet loads

Answer 10

50 A

Question 10

A ________ branch circuit shall be permitted to supply cooking appliances that are fastened to place

Answer 10

40-50 A

Question 11

In every kitchen, family room, dining room, living room, parlor, library, den, sunroom, bedroom, recreation room, or similar room or area of dwelling units, receptacle outlets shall be installed not more than ________ horizontally from the other receptacle outlet.

Answer 11

1800 mm (1.8m)

Question 12

Receptacle outlets shall be located above, but not more than _______ above, the countertop.

Answer 12

500 mm

Question 13

Bathrooms shall have at least one receptacle within ______ from the outside edge of each basin.

Answer 13

900 mm

Question 14

For a one-family dwelling and each unit of dwelling units shall have at least one accessible outlet at grade level not more than _______ in front and back of the dwelling unit.

Answer 14

2000 mm

Question 15

Laundry areas, basement and garages shall have at least _______ receptacle installed for the laundry.

Answer 15

one

Question 16

In dwelling units, hallways that have __________ or more in length shall require at least one receptacle outlet.

Answer 16

3000 mm (3m)

Question 17

Special individual outlets such as heating, air-conditioning and refrigeration equipment outlet shall be installed and be located on the same level _______ within the equipment.

Answer 17

7600 mm

Question 18

Where a feeder supplies continuous loads or any combination of continuous and noncontinuous loads, the minimum feeder conductor size shall have an allowable ampacity not less than the noncontinuous load plus _______ of the continuous load

Answer 18

125%

Question 19

Where a feeder supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent device shall not be less that the noncontinuous load plus ______ of the continuous load.

Answer 19

125%

Question 20

This Article provides requirements for calculating branch-circuit, feeder and other service loads.

Answer 20

Article 2.20 Branch Circuit, Feeder, and Service Calculations

Question 21

Conductors that supply a single motor used in a continuous duty application shall have an ampacity of not less than _______ of the motor full-load current rating.

Answer 21

125%

Question 22

Outlets for heavy-duty lamp holders shall be calculated at a minimum of ___________.

Answer 22

600VA

Question 23

Outlets for sign and outline lighting shall be calculated at a minimum of ___________.

Answer 23

1200VA

Question 24

Receptacle outlets shall be calculated at not less than _______ for each single or for each multiple receptacle on one yoke.

Answer 24

180 VA

Question 25

In each dwelling unit, the small-appliance circuit load shall be calculated at ______ for each 2-wire small-appliance branch circuit.

Answer 25

1500 VA

Question 26

A load of not less than shall be ________ included for each 2-wire laundry branch circuit installed.

Answer 26

1500 VA

Question 27

It shall be permissible to apply a demand factor of ______ to the nameplate rating load of four or more appliances fastened in place, other than electric ranges, clothes dryers, space-heating equipment, or air-conditioning equipment, that are served by the same feeder or service in one-family, two-family, or multifamily dwelling.

Answer 27

75%

Question 28

The load for household electric clothes dryers in a dwelling unit(s) shall be either ______ of the nameplate rating, whichever is larger, for each dryer served.

Answer 28

5000 VA

Question 29

This article covers service conductors and equipment for control and protection of service and their installation requirements.

Answer 29

Article 2.30 Services

Question 30

The overhead service conductors shall not be smaller than _____________.

Answer 30

8.0 mm^2 Cu or 14 mm^2 Al or copper-clad aluminum.

Question 31

Each service drop, set of overhead service conductors, set of underground service conductors, or service lateral shall supply only ____ set of service entrance conductors.

Answer 31

one

Question 32

The minimum service entrance conductor size shall have an allowable ampacity not less than the sum of the non-continuous load plus _____ of the continuous load.

Answer 32

125%

Question 33

Protects all the internal components of the circuit breaker. It also supports the components and provides insulation to contain the arc. Depending on the current and voltage used, they are further available in three forms: molded, insulated, and metal.

Answer 33

Frame or external casing

Question 34

Its function is to open or close the contacts of the circuit breaker. All types of circuit breakers use some method to disconnect the power supply. These typically include spring-loaded switches, solenoid, hydraulic, and pneumatic switches.

Answer 34

Operating Mechanism

Question 35

The function of contacts is to pass the current through the circuit breaker when they are closed. Generally, a circuit breaker has two electrical contacts: a static contact and a temporary contact.

Answer 35

Electrical contacts

Question 36

This usually extinguishes the arc in the event of a fault. When the contacts are disconnected, electricity can jump through the gap between the end parts of the contact. This causes an arc of electricity that can reach very high temperatures.

Answer 36

Arc Extinguisher

Question 37

It helps to detect abnormal current flow in the event of overcurrent and short circuit. It causes the operating mechanism to open the contacts.

Answer 37

Trip Unit

Question 38

Is a safety switch usually built into your home’s electrical system. It looks like a switch that helps to stop the flow of electricity to any component or device that consumes a lot of power.

Answer 38

AC Circuit Breaker

Question 39

This type of circuit breaker is used with a voltage rating of more than 600 volts. These are powered by solenoids, with current sensing protective relays driven through current transformers.

Answer 39

High Voltage Circuit Breaker

Question 40

This type of circuit breaker is suitable for circuits rated at 600 volts or less. The most commonly used low-voltage circuit breaker is a molded case circuit breaker. Low-voltage circuit breakers are commonly seen in domestic, commercial, and industrial applications.

Answer 40

Low Voltage Circuit Breaker

Question 41

These types of circuit breakers serve as a substitute for fuses and are used to protect the circuit from excess current. They protect low voltage circuits 240/415V AC with a wide range of current ratings below 125V.

Answer 41

Miniature Circuit Breaker (MCB)

Question 42

are designed to provide protection against over-current. They are suitable for use in circuits where the maximum expected current is known and relatively constant, such as lighting circuits.

Answer 42

Type A MCBs

Question 42

are designed to provide protection against over-current and short circuits. They are suitable for use in circuits where the load is variable, such as in motor circuits.

Answer 42

Type B MCBs

Question 43

are designed to provide protection against both over-current and earth fault currents.

Answer 43

Type C MCBs

Question 43

are designed to provide protection against over-current and earth fault currents, with a higher tripping threshold than Type C MCBs.

Answer 43

Type D MCBs

Question 44

are designed to provide protection against over-current and earth fault currents in residual current devices (RCDs) used in electrical systems.

Answer 44

Type G MCBs

Question 45

are designed to provide protection against over-current and earth fault currents in electrical systems that are powered by direct current (DC).

Answer 45

Type H MCBs

Question 46

are designed to provide protection against over-current and short circuits in electrical systems with high fault levels.

Answer 46

Type K MCBs

Question 47

is a circuit breaker with a high current rating of up to 2500 amps. These are generally seen where the current rating exceeds the limits of the MCB (Miniature Circuit Breaker).

Answer 47

Molded Case Circuit Breaker (MCCB)

Question 48

This circuit breaker works on a thermal-magnetic tripping mechanism where the thermal mechanism is used for overloading and magnetic is used for short circuit conditions.

Answer 48

Molded Case Circuit Breaker (MCCB)

Question 49

These molded case breaker types are meant to trip if they detect a current 3-5 times higher than what they are rated for, usually within 0.04 to 13 seconds, dependent on the rating of the breaker.

Answer 49

Type B MCCB

Question 50

These types of molded case breaker are built to trip at fault currents that are between 5-10 times the rated current, with durations of 0.04-5 seconds.

Answer 50

Type C MCCB

Question 51

This type of MCCB has a higher tolerance to fault currents. It trips at between 10-20 times its rated current, which is quite high, and for between 0.04 and 3 seconds.

Answer 51

Type D MCCB

Question 52

These molded case circuit breaker types trip when they detect current values between 15-20 times the rated value and in a time range of 0.04 to 5 seconds. These are specifically designed for short circuit currents, hence their high sensitivity rating.

Answer 52

Type Z MCCB

Question 53

is specifically designed to trip when the current reaches between 8-12 times the rated value and for 0.04 to 5 seconds.

Answer 53

Type K MCCB

Question 54

is the most common type and used in all kinds of low-voltage AC systems.

Answer 54

AC MCCB

Question 55

is mainly used in solar power systems to protect against DC overloads and other DC circuit faults.

Answer 55

DC MCCB

Question 56

A _________________ protects electrical equipment operating with DC. It has additional arc extinguishing measures. These are relatively new technologies for most homeowners because most appliances are used in the homework with AC. These circuit breakers use 24 VDC to 48 VDC programmable logic controllers (PLCs).

Answer 56

DC Circuit Breaker

Question 57

is a switching device that interrupts the normal flow of current in the circuit. These circuit breakers provide a very efficient way of power transmission over long distances. Nowadays, there are used in various green energy generation.

Answer 57

HVDC Circuit Breaker

Question 58

These types of circuit breakers use an insulating oil (which has better dielectric strength than air). The insulating oil is a dielectric medium to extinguish the arc and break the circuit safely.

Answer 58

Oil Circuit Breaker

Question 59

These types of circuit breakers use oil arc quenching media as well as insulating media between the current-carrying contacts and the earthing parts of the breaker. The amount of oil required in this circuit breaker depends on the system voltage.

Answer 59

Bulk Oil Circuit Breaker

Question 60

is an electrical protection device used for short circuit and overcurrent protection. It operates in air at atmospheric pressure and uses air blast as an arc quenching medium. ACBs are commonly used in low voltage applications, up to 15kV, with amperage ratings ranging from 800A to 10kA.

Answer 60

Air Circuit Breaker (ACB)

Question 61

Multiple grounding rod installed shall not be less than _______ apart.

Answer 61

1800 mm (6 ft.)

Question 61

The electrode shall be installed such that at least _______ of length is in contact with the soil.

Answer 61

2400 mm