250. Grounding and Bonding

A service is supplied by three metal raceways, each containing 600 kcmil ungrounded conductors. Determine the copper supply-side bonding jumper size for each service raceway. 1. 1/0 AWG 2. 3/0 AWG 3. 250 kcmil 4. 500 kcmi

1/0 AWG Code Reference: 250.102(C)(2) and Table 250.102(C)(1)

What is the minimum size copper equipment bonding jumper for a 40A rated circuit? 1. 14 AWG 2. 12 AWG 3. 10 AWG 4. 8 AWG

10 AWG Code Reference: 250.102(D) and Table 250.122

Listed FMC can be used as the equipment grounding conductor if the length in any ground return path does not exceed 6 ft and the circuit conductors contained in the conduit are protected by overcurrent devices rated at _____ or less. 15A 20A 30A 60A

20A is the correct answer. Code Reference: 250.118(5)b and d

What is the minimum size copper supply-side bonding jumper for a service raceway containing 4/0 THHN aluminum conductors? 1. 6 AWG aluminum 2. 4 AWG aluminum 3. 4 AWG copper 4. 3 AWG copper

4 AWG copper Code Reference: 250.102(C)(1) and Table 250.102(C)(1)

At existing buildings or structures, an intersystem bonding termination is not required if other acceptable means of bonding exists. An external accessible means for bonding communications systems together can be by the use of a(n) _____. 1. nonflexible metallic raceway 2. exposed grounding electrode conductor 3. connection to a grounded raceway or equipment approved by the authority having jurisdiction 4. any of these

4. any of these Code Reference: 250.94(A) Ex

A means external to enclosures for connecting intersystem _____ conductors shall be provided at the service equipment or metering equipment enclosure and disconnecting means of buildings or structures supplied by a feeder. 1. bonding 2. ungrounded 3. secondary 4. a and b

Bonding Code Reference: 250.94(A)

Exposed structural metal interconnected to form a metal building frame that is not intentionally grounded or bonded and is likely to become energized, shall be bonded to the _____. 1. service equipment enclosure or building disconnecting means 2. grounded conductor at the service 3. grounding electrode conductor where of sufficient size 4. any of these

any of these Code Reference: 250.104(C)

Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be ensured by _____. 1. bonding equipment to the grounded service conductor 2. connections utilizing threaded couplings on enclosures, if made up wrench tight 3. other listed bonding devices, such as bonding-type locknuts, bushings, or bushings with bonding jumpers 4. any of these

any of these Code Reference: 250.92(B)(1) through (4)

The Code requires the installation of an equipment grounding conductor of the wire type in _____. 1. rigid metal conduit (RMC) 2. intermediate metal conduit (IMC) 3. electrical metallic tubing (EMT) 4. none of these

none of these is the correct answer. Code Reference: 250.118(2), (3), and (4)

Except as provided in 250.122(F)(2)(b) for raceway or cable tray installations, the equipment grounding conductor in each multiconductor cable shall be sized in accordance with 250.122 based on the _____. 1. largest circuit conductor 2. overcurrent protective device for the feeder or branch circuit 3. smallest branch-circuit conductor 4. overcurrent protective device for the service

overcurrent protective device for the feeder or branch circuit is the correct answer. Code Reference: 250.122(F)(2)

A wire-type equipment grounding conductor is permitted to be used as a grounding electrode conductor if it meets all of the requirements of Parts II, III, and VI of Article 250. True False

True is the correct answer. Code Reference: 250.121 Ex

Equipment grounding conductors of the wire type shall not be required to be larger than the circuit conductors. True False

True is the correct answer. Code Reference: 250.122(A)

Portable generators are required to be grounded if the generator only supplies receptacles mounted on the generator? 1. True 2. False

False 250.34(A)(1) 250.34 Portable and Vehicle-Mounted Generators. (A) Portable Generators. The frame of a portable generator shall not be required to be connected to a grounding electrode as defined in 250.52 for a system supplied by the generator under the following conditions: (1) The generator supplies only equipment mounted on the generator, cord-and-plug-connected equipment through receptacles mounted on the generator...

Communications system bonding termination connections to an aluminum or copper busbar shall not be less than 1/4 in. thick x 2 in. wide and of sufficient length to accommodate at least _____ terminations for communications systems in addition to other connections. 1. two 2. three 3. four 4. five

THREE Code Reference: 250.94(B)

A building or structure shall have the interior metal water piping system bonded with a bonding jumper sized in accordance with _____. 1. Table 250.102(C)(1) 2. Table 250.122 3. Table 310.15(B)(16) 4. none of these

Table 250.102(C)(1) Code Reference: 250.104(A)(3)

Metal piping, including gas piping shall be considered bonded by the equipment grounding conductor for the circuit that is likely to energize the piping system. True False

True Code Reference: 250.104(B)(1)

Where circuit conductors are installed in parallel in multiple raceways or cables and include an EGC of the wire type, the equipment grounding conductor shall be installed in parallel in each raceway or cable, sized in compliance with 250.122 based on the overcurrent protective device for the feeder or branch circuit. True False

True is the correct answer. Code Reference: 250.122(F)(1)(b)

A grounded circuit conductor is permitted to ground noncurrent-carrying metal parts of equipment, raceways, and other enclosures on the supply side or within the enclosure of the ac service disconnecting means. True False

True is the correct answer. Code Reference: 250.142(A)(1)

The metal water piping system(s) installed in or attached to a building or structure [250.104(A)(3)] shall be bonded to _____. 1. the building or structure disconnecting means enclosure where located at the building or structure 2. the equipment grounding conductor run with the supply conductors 3. one or more grounding electrodes used 4. any of these

any of these is the correct answer. Code Reference: 250.104(A)(3)(1), (2), and (3)

Listed FMC and LFMC shall contain an equipment grounding conductor if the raceway is installed for the reason of _____. 1. physical protection 2. flexibility after installation 3. minimizing transmission of vibration from equipment 4. b or c

b or c is the correct answer. Code Reference: 250.118(5)e

Bonding shall be provided where necessary to ensure _____ and the capacity to conduct safely any fault current likely to be imposed. 1. electrical continuity 2. fiduciary responsibility 3. listing requirements are met 4. sufficient electrical demand

electrical continuity Code Reference: 250.90.

A separate bonding jumper to the building structural metal shall not be required if the metal frame of a building or structure is used as the _____ for the separately derived system. 1. bonding jumper 2. ground-fault current path 3. grounding electrode 4. none of these

grounding electrode is the correct answer. Code Reference: 250.104(D)(2) Ex 1

When a single equipment grounding conductor is used for multiple circuits in the same raceway, cable, or cable tray, the single equipment grounding conductor shall be sized according to the _____. 1. combined rating of all the overcurrent devices 2. largest overcurrent device of the multiple circuits 3. combined rating of all the loads 4. any of these

largest overcurrent device of the multiple circuits is the correct answer. Code Reference: 250.122(C)

Metal water piping systems and structural metal that is interconnected to form a building frame shall be bonded to separately derived systems in accordance with 250.104(D)(1) through 250.104(D)(3). True False

True Code Reference: 250.104(D)

Means for connecting intersystem bonding conductors are not required where communications systems are not likely to be used. True or False

True Code Reference: 250.94 Ex to (A) and (B)

Equipment grounding conductors for motor branch circuits shall be sized in accordance with Table 250.122, based on the rating of the _____ device. 1. motor overload 2. motor over-temperature 3. branch-circuit short-circuit and ground-fault protective 4. feeder overcurrent protection

branch-circuit short-circuit and ground-fault protective is the correct answer. Code Reference: 250.122(D)(1)

Short sections of metal enclosures or raceways used to provide support or protection of _____ from physical damage shall not be required to be connected to the equipment grounding conductor. 1. conduit 2. feeders under 600V 3. cable assemblies 4. none of these

cable assemblies is the correct answer. Code Reference: 250.86 Ex 2

When ungrounded circuit conductors are increased in size to account for voltage drop, the wire-type equipment grounding conductor shall be proportionately increased in size according to the increase in size of the ungrounded conductors using their _____. 1. ampacity 2. circular mil area 3 diameter 4. none of these

circular mil area is the correct answer. Code Reference: 250.122(B)

The structural metal frame of a building can be used as the required equipment grounding conductor for ac equipment. True False

False is the correct answer. Code Reference: 250.136(A)