Residential and Other Calculations Flashcards
The maximum current in amperes that a conductor can carry continuously under the conditions of use without exceeding its temperature rating is known as its _____.
Answer 1: short-circuit rating
Answer 2: ground-fault rating
Answer 3: ampacity
Answer 4: all of these
Answer 3: ampacity
100 Ampacity
A _____ consists of two or more ungrounded conductors that have a voltage between them and a neutral conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral conductor of the system.
Answer 1: multi-phase branch circuit
Answer 2: three-phase lighting supply circuit
Answer 3: poly-phase branch circuit
Answer 4: multiwire branch circuit
Answer 4: multiwire branch circuit
100 Branch Circuit, Multiwire (Multiwire Branch Circuit)
A(An) _____ circuit breaker is a qualifying term indicating that there is a delay purposely introduced in the tripping action of the circuit breaker and the delay decreases as the magnitude of the current increases.
Answer 1: adverse time
Answer 2: inverse time
Answer 3: time delay
Answer 4: timed unit
Answer 2: inverse time
100 Circuit Breaker, Inverse Time (Inverse Time Circuit Breaker)
A generator is a machine that converts mechanical energy into electrical energy by means of a _____ and alternator and/or inverter.
Answer 1: converter
Answer 2: rectifier
Answer 3: prime mover
Answer 4: turbine
Answer 3: prime mover
100 Generator (Generator Set)
Article 210 provides the general requirements for _____ not over 1000V ac 1500V dc nominal.
Answer 1: outside branch circuits
Answer 2: branch circuits
Answer 3: ungrounded conductors
Answer 4: feeder calculations
Answer 2: branch circuits
210.1
Where a branch circuit supplies continuous loads and/or noncontinuous loads the rating of the overcurrent device shall not be less than the noncontinuous load plus ____ of the continuous load.
Answer 1: 80 percent
Answer 2: 115 percent
Answer 3: 120 percent
Answer 4: 125 percent
Answer 4: 125 percent
210.20(A)
Article _____ provides requirements for calculating branch-circuit feeder and service loads.
Answer 1: 200
Answer 2: 210
Answer 3: 220
Answer 4: 230
Answer 3: 220
220.1
When calculations in Article 220 result in a fraction of an ampere that is less than _____ such fractions can be dropped.
Answer 1: 0.49
Answer 2: 0.5
Answer 3: 0.51
Answer 4: 0.8
Answer 2: 0.5
220.5(B)
Outlets supplying luminaires shall be calculated based on the maximum _____ rating of the equipment.
Answer 1: power
Answer 2: true power
Answer 3: voltage
Answer 4: volt-ampere
Answer 4: volt-ampere
220.14(D)
Sign and outline lighting outlets are to be calculated at a minimum of _____ for each required branch circuit specified in 600.5(A).
Answer 1: 1000 VA
Answer 2: 1200 VA
Answer 3: 1500 VA
Answer 4: 2000 VA
Answer 2: 1200 VA
220.14(F)
If a motor or air-conditioning load is part of the noncoincident load and is not the largest of the noncoincident loads 125 percent of either the motor load or air-conditioning load whichever is _____ shall be used in the calculation.
Answer 1: less
Answer 2: smaller
Answer 3: larger
Answer 4: less or smaller
Answer 3: larger
220.60.
If an energy management system (EMS) is used to limit the current to a feeder or service the set point value of the EMS shall be considered _____.
Answer 1: at 80 percent
Answer 2: at 90 percent
Answer 3: at 100 percent
Answer 4: a continuous load
Answer 4: a continuous load
220.70.
Solid aluminum conductors of 8 AWG 10 AWG and 12 AWG shall be made of an AA-_____ series electrical grade aluminum alloy conductor material.
Answer 1: 1350
Answer 2: 2000
Answer 3: 6000
Answer 4: 8000
Answer 4: 8000
310.3(B)(1)
Stranded aluminum conductors 8 AWG through 1000 kcmil marked as _____ shall be made of an AA-8000 series electrical grade aluminum alloy conductor material.
Answer 1: Type UF
Answer 2: Type NM
Answer 3: Type NMC
Answer 4: Type SE
Answer 4: Type SE
310.3(B)(2)
The _____ core of a copper-clad aluminum conductor shall be made of an AA-8000 series electrical grade aluminum alloy conductor material.
Answer 1: aluminum
Answer 2: copper
Answer 3: steel
Answer 4: iron
Answer 1: aluminum
310.3(B)(3)
Conductors in Article 310 shall be of copper aluminum or copper-clad aluminum unless otherwise specified. Copper-clad aluminum conductor material shall be _____.
Answer 1: identified for the use
Answer 2: listed
Answer 3: indicated as suitable
Answer 4: approved
Answer 2: listed
310.3(B)(4)
Where installed in raceways conductors _____ and larger shall be stranded unless specifically permitted or required elsewhere in the NEC.
Answer 1: 10 AWG
Answer 2: 8 AWG
Answer 3: 6 AWG
Answer 4: 4 AWG
Answer 2: 8 AWG
310.3(C)
Insulated conductors with the letters HH in their designation have a _____ insulation rating in a dry location.
Answer 1: 60°C
Answer 2: 75°C
Answer 3: 90°C
Answer 4: 110°C
Answer 3: 90°C
310.4(1) Table
Insulated conductors with letter designation of _____ are permitted in a wet location with a maximum operating temperature of 90°C.
Answer 1: USE
Answer 2: RHW
Answer 3: XHWN
Answer 4: THWN-2
Answer 4: THWN-2
310.4(1) Table
Where there are no adjustment or correction factors required the service conductors for a rated service of _____ supplying the entire load associated with an individual dwelling unit Table 310.12(A) shall be permitted to be applied.
Answer 1: 100A
Answer 2: 200A
Answer 3: 400A
Answer 4: all of these
Answer 4: all of these
310.12(A)
Where there are no adjustment or correction factors required the feeder conductors rated between 100A and _____ supplying the entire load associated with an individual dwelling unit Table 310.12(A) shall be permitted to be applied..
Answer 1: 150A
Answer 2: 200A
Answer 3: 300A
Answer 4: 400A
Answer 4: 400A
310.12(B)
No conductor shall be used where its _____ temperature exceeds that designated for the type of insulated conductor involved.
Answer 1: operating
Answer 2: ambient
Answer 3: highest
Answer 4: lowest
Answer 1: operating
310.14(A)(3)
The _____ rating of a conductor is the maximum temperature at any location along its length which the conductor can withstand over a prolonged period of time without serious degradation.
Answer 1: ampacity
Answer 2: temperature
Answer 3: conductivity
Answer 4: short-circuit
Answer 2: temperature
310.14(A)(3) Informational Note 1
There are four principal determinants of conductor operating temperature one of which is _____ generated internally in the conductor as the result of load current flow including fundamental and harmonic currents.
Answer 1: friction
Answer 2: magnetism
Answer 3: heat
Answer 4: compatibility
Answer 3: heat
310.14(A)(3) Informational Note 1(2)
In accordance with Article 310 temperature correction and adjustment factors are permitted to be applied to the ampacity for the temperature rating of the _____ if the corrected and adjusted ampacity does not exceed the ampacity for the temperature rating of the termination in accordance with 110.14(C).
Answer 1: conductor
Answer 2: feeder
Answer 3: service
Answer 4: termination
Answer 1: conductor
310.15(A)
Type _____ insulated conductors shall not be subject to ampacity adjustment where installed exposed to direct sunlight on a rooftop.
Answer 1: THW-2
Answer 2: XHHW-2
Answer 3: THWN-2
Answer 4: RHW-2
Answer 2: XHHW-2
310.15(B)(2) Ex
A raceway contains two three-phase 4-wire circuits where the neutrals carry only the unbalanced current from the other conductors. The ampacity adjustment factor for these conductors is _____.
Answer 1: 70 percent
Answer 2: 80 percent
Answer 3: 90 percent
Answer 4: 100 percent
Answer 2: 80 percent
310.15(C)(1) Table
Conductor adjustment factors shall not apply to conductors in raceways having a length not exceeding _____.
Answer 1: 12 in.
Answer 2: 24 in.
Answer 3: 36 in.
Answer 4: 48 in.
Answer 2: 24 in.
310.15(C)(1)(b)
A(An) _____ conductor that carries only the unbalanced current from other conductors of the same circuit shall not be required to be counted when applying the provisions of 310.15(C)(1).
Answer 1: neutral
Answer 2: ungrounded
Answer 3: grounding
Answer 4: bonded
Answer 1: neutral
310.15(E)(1)
On a 4-wire three-phase wye circuit where the major portion of the neutral load consists of _____ loads the neutral conductor shall be considered a current-carrying conductor.
Answer 1: 240V
Answer 2: 277V
Answer 3: nonlinear
Answer 4: linear
Answer 3: nonlinear
310.15(E)(3)
For the purposes of ampacity adjustment when determining the number of current-carrying conductors a grounding or bonding conductor _____ be counted when applying the provisions of 310.15(C)(1).
Answer 1: shall not
Answer 2: shall
Answer 3: is permitted to
Answer 4: can
Answer 1: shall not
310.15(F)
The ampacities specified in Table 310.16 apply to _____.
Answer 1: conductors rated 60°C 75°C or 90°C
Answer 2: wiring installed in an ambient temperature of 86°F
Answer 3: where there is not more than three current-carrying conductors
Answer 4: all of these
Answer 4: all of these
310.16(2), (3), and (4)
The minimum size THHN conductor for a 150A noncontinuous load is _____.
Answer 1: 1 AWG
Answer 2: 1/0 AWG
Answer 3: 2/0 AWG
Answer 4: 3/0 AWG
Answer 2: 1/0 AWG
310.16 Table
The minimum conductor size required for a 60A load if the terminals are rated 75°C is _____ THW copper.
Answer 1: 2 AWG
Answer 2: 4 AWG
Answer 3: 6 AWG
Answer 4: 8 AWG
Answer 3: 6 AWG
310.16 Table
The minimum size THW service-entrance conductors for a 200A commercial service is _____.
Answer 1: 2/0 AWG
Answer 2: 3/0 AWG
Answer 3: 4/0 AWG
Answer 4: 250 KCMIL
Answer 2: 3/0 AWG
310.16 Table
The conductor ampacity for 6 THW is _____.
Answer 1: 55A
Answer 2: 65A
Answer 3: 70A
Answer 4: 80A
Answer 2: 65A
310.16 Table
The 90°C rating shall be permitted to be used for ampacity adjustment and correction calculations for Type NM cable provided the final calculated ampacity does not exceed that of a _____ rated conductor.
Answer 1: 60°C
Answer 2: 75°C
Answer 3: 90°C
Answer 4: 104°C
Answer 1: 60°C
334.80.
For Types NM and NMC cable the _____ rating shall be permitted to be used for ampacity adjustment and correction calculations provided the final calculated ampacity does not exceed that of a 60°C rated conductor.
Answer 1: 60°C
Answer 2: 75°C
Answer 3: 90°C
Answer 4: 104°C
Answer 3: 90°C
334.80.
The ampacity adjustment factors in 310.15(C)(1) shall be applied to a metal wireway only where the number of current-carrying conductors in any cross section of the wireway exceeds _____.
Answer 1: 30
Answer 2: 40
Answer 3: 50
Answer 4: 60
Answer 1: 30
376.22(B)
Where insulated conductors are deflected within a metal wireway the wireway shall be sized to meet the bending requirements corresponding to _____ per terminal in Table 312.6(A).
Answer 1: one wire
Answer 2: two wires
Answer 3: three wires
Answer 4: four wires
Answer 1: one wire
376.23(A)
If a branch circuit supplies a single nonmotor-operated appliance the rating of overcurrent protection shall not exceed _____ if the overcurrent protection rating is not marked and the appliance is rated 13.30A or less.
Answer 1: 15A
Answer 2: 20A
Answer 3: 25A
Answer 4: 30A
Answer 2: 20A
422.11(E)(2)
If a branch circuit supplies a single nonmotor-operated appliance the rating of overcurrent protection shall not exceed _____ of the appliance rated current if the overcurrent protection rating is not marked and the appliance is rated over 13.30A.
Answer 1: 100 percent
Answer 2: 125 percent
Answer 3: 150 percent
Answer 4: 160 percent
Answer 3: 150 percent
422.11(E)(3)
The branch-circuit conductor(s) ampacity shall not be less than _____ of the load of the fixed electric space-heating equipment and any associated motor(s).
Answer 1: 80 percent
Answer 2: 110 percent
Answer 3: 125 percent
Answer 4: 150 percent
Answer 3: 125 percent
424.4(B)
Article _____ covers motors motor branch-circuit and feeder conductors and their protection motor overload protection motor control circuits motor controllers and motor control centers.
Answer 1: 410
Answer 2: 430
Answer 3: 440
Answer 4: 450
Answer 2: 430
430.1
For general motor applications the NEC table values for full load current values shall be used instead of the actual current rating marked on the motor nameplate when determining overload protection.
Answer 1: TRUE
Answer 2: FALSE
Answer 2: FALSE
430.6(A)(1)
For general motor applications separate motor overload protection shall be based on _____.
Answer 1: NEC Tables 430.248 and 430.250
Answer 2: the manufacturer’s instructions
Answer 3: the motor disconnect current rating
Answer 4: the motor nameplate current rating
Answer 4: the motor nameplate current rating
430.6(A)(2)(1)<br></br> 2023 UNEC1, Chapter 4
Branch-circuit conductors supplying a single continuous-duty motor shall have an ampacity not less than _____ rating.
Answer 1: 125 percent of the motor’s nameplate current
Answer 2: 125 percent of the motor’s full-load current
Answer 3: 125 percent of the motor’s full locked-rotor
Answer 4: 80 percent of the motor’s full-load current
Answer 2: 125 percent of the motor’s full-load current
430.22
Part IV of Article 430 specifies devices intended to protect _____ against overcurrent due to short circuits or ground faults.
Answer 1: motor branch-circuit conductors
Answer 2: motor control apparatus
Answer 3: motors
Answer 4: all of these
Answer 4: all of these
430.51
Short-circuit and ground-fault protection for a branch-circuit to which a motor or motor-operated appliance is connected shall be capable of carrying the ____ current of the motor.
Answer 1: ampacity
Answer 2: time delay
Answer 3: thermal protection
Answer 4: starting
Answer 4: starting
430.52(B)
The maximum dual-element time-delay fuse branch-circuit protection for a single-phase motor is _____ of the appropriate full-load current rating found in Table 430.248.
Answer 1: 100 percent
Answer 2: 115 percent
Answer 3: 125 percent
Answer 4: 175 percent
Answer 4: 175 percent
430.52(C)(1) and Table 430.52(C)(1)
The maximum rating or setting of an inverse time breaker used as the motor branch-circuit short-circuit and ground-fault protective device for a single-phase motor is _____ of the full-load current given in Table 430.248.
Answer 1: 100 percent
Answer 2: 115 percent
Answer 3: 125 percent
Answer 4: 250 percent
Answer 4: 250 percent
430.52(C)(1) and Table 430.52(C)(1)
Where the motor short-circuit and ground-fault protection devices determined by Table 430.52(C)(1) do not correspond to the standard sizes or ratings a _____ rating that does not exceed the next _____ standard ampere rating is permitted.
Answer 1: higher
Answer 2: lower
Answer 3: smaller
Answer 4: larger
Answer 1: higher
430.52(C)(1)(a)
The full-load current of a 115V 1 hp single-phase ac motor is _____.
Answer 1: 12A
Answer 2: 14A
Answer 3: 16A
Answer 4: 20A
Answer 3: 16A
430.248 Table
The full-load current of a 230V 1.50 hp single-phase ac motor is _____.
Answer 1: 10A
Answer 2: 12A
Answer 3: 14A
Answer 4: 16A
Answer 1: 10A
430.248 Table
The full-load current of a three-phase 208V 2 hp motor is _____.
Answer 1: 7.50A
Answer 2: 12A
Answer 3: 14A
Answer 4: 16A
Answer 1: 7.50A
430.250 Table
The full-load current of a three-phase 208V 7.50 hp motor is _____.
Answer 1: 19A
Answer 2: 22A
Answer 3: 24.20A
Answer 4: 38A
Answer 3: 24.20A
430.250 Table
The full-load current of a three-phase 230V 10 hp motor is _____.
Answer 1: 19A
Answer 2: 22A
Answer 3: 28A
Answer 4: 38A
Answer 3: 28A
430.250 Table
The full-load current of a three-phase 460V 15 hp motor is _____.
Answer 1: 19A
Answer 2: 21A
Answer 3: 29A
Answer 4: 42A
Answer 2: 21A
430.250 Table
Article 450 covers the installation of all _____.
Answer 1: motors and motor control centers
Answer 2: refrigeration and air-conditioning equipment
Answer 3: transformers
Answer 4: generators
Answer 3: transformers
450.1
The primary overcurrent protection for a transformer rated 1000V nominal or less with no secondary protection and having a primary current rating of _____ shall be set at not more than 125 percent or a higher rating that does not exceed the next higher standard rating shall be permitted.
Answer 1: 9A or more
Answer 2: less than 9A
Answer 3: 2A or more
Answer 4: less than 2A
Answer 1: 9A or more
450.3(B) Table Note 1
Article 625 covers the electrical conductors and equipment connecting an electric vehicle to premises wiring for the purposes of ____.
Answer 1: charging
Answer 2: power export
Answer 3: bidirectional current flow
Answer 4: any of these
Answer 4: any of these
625.1
Each outlet installed for the purpose of supplying EVSE (electric vehicle supply equipment) greater than _____ or 120V charging electric vehicles shall be supplied by an individual branch circuit.
Answer 1: 12A
Answer 2: 16A
Answer 3: 18A
Answer 4: 20A
Answer 2: 16A
625.40.
Overcurrent protection for circuits supplying electric vehicle supply (EVSE) and wireless power transfer (WPTE) equipment shall have a current rating of not less than _____ of the maximum load of the electric vehicle supply equipment.
Answer 1: 100 percent
Answer 2: 110 percent
Answer 3: 125 percent
Answer 4: 150 percent
Answer 3: 125 percent
625.41
Electric vehicle charging loads shall be considered to be a(an) _____ load.
Answer 1: noncontinous
Answer 2: hard
Answer 3: extended
Answer 4: continuous
Answer 4: continuous
625.42
