3rd 2nd Q2 Ch 7&8
What is the minimum-size aluminum equipment grounding conductor in each MC cable assembly run in a parallel arrangement for an 800-ampere feeder?
3/0 AWG
When an equipment bonding jumper is installed on the outside of flexible metal conduit or liquidtight flexible metal conduit, the length of the jumper is generally limited to not exceeding ? in length.
6 feet
Where a motor circuit is installed and the rating of the branch-circuit short-circuit ground-fault protection device is 100 amperes, what is the minimum-size copper equipment grounding conductor required for the motor?
8 AWG
The bonding connection for a metal water piping system is required to be readily accessible unless it is a buried connection or a connection made using the exothermic welding process.
False. There is a difference between the terms accessible and readily accessible. Section 250.104(A) does not currently offer an exception for the required accessibility for the bonding connection to a metal water pipe. This relates back to old requirements for testing and being able to disconnect this connection during testing procedures.
Which of the following is not permitted as a means for identifying an equipment grounding conductor?
Gray insulation
Fittings for electrical metallic tubing installations are required to be ? .
Installed in a neat and workmanlike manner, Listed, Made up tight using suitable tools
Which NEC table is used to size equipment bonding jumpers on the load side of a fuse or circuit breaker?
Table 250.122
Liquidtight flexible metal conduit is not permitted to be used as an equipment grounding conductor except when it meets all but which of the following conditions?
The conduit is installed where flexibility is necessary after installation for movement or vibration.
Noncoductive coatings on equipment to be grounded shall be removed from threads and other contact surfaces to ensure good electrical continuityor be connected by means of fittings designed so as to make such removal unnecessary
True 250.12
The term ? means connected to ground or to a conductive body that extends the ground connection
grounded
Equipment grounding conductors are not required to be larger than the circuit conductors supply equipment.
true
If a feeder circuit is installed in (two conductors per phase) parallel using a single flexible metal conduit raceway, how many wire-type equipment grounding conductors are required in the raceway?
1
An aluminum equipment bonding jumper installed on the load side of a 400-ampere overcurrent device must not be smaller than ? .
1 AWG
What is the minimum size required for the aluminum equipment bonding jumper on the load side of the service disconnect of a Service entrance conductor size of 750 kcmil?
1 AWG
Where multiple taps to an 800-ampere feeder are made for three 200-ampere enclosed circuit breaker assemblies, what is the minimum-size wire-type equipment grounding conductor that must be run in nonmetallic raceways with the tap conductors to each 200-ampere circuit breaker enclosure?
1/0 AWG copper
When a gas furnace is supplied by a 30-ampere branch circuit, what is the minimum size required for bonding the metal gas piping system?
10 AWG. 250.104(B), where the bonding for the gas piping system can be accomplished using the branch circuit equipment grounding conductor for the circuit supplying the equipment. Also point out that Informational Note No. 2 refers users to additional bonding requirements that are provided in Section 7.13 of NFPA 54, National Fuel Gas Code. The question asks for the minimum, and the type of gas piping system is not provided in the question.
Aluminum equipment grounding conductors are not permitted to be terminated within ? of the Earth.
18"
What is the minimum size required for the copper supply-side bonding jumper in this service with three 4/0 AWG service conductors (B/R/N)?
2 AWG
what is the minimum size required for the copper supply-side bonding jumper in this service (500 Kcmil aluminum) and what is the minimum size required for a copper load-side bonding jumper?
2 AWG/ 4AWG
What is the minimum-size copper supply-side bonding jumper for a 600-ampere service supplied with two 400 kcmil conductors (800 kcmil is the largest ungrounded service-entrance conductor per phase) if all the conductors are in a single six-inch raceway?
2/0 AWG
What is the circular mil area of a 4/0 AWG copper conductor?
211,600
Where a feeder supplies a separate building or structure, and a metal frame of that structure must be bonded, what NEC table is used to size the bonding jumper?
250.66
What is the minimum-size aluminum equipment grounding conductor required for an 80-ampere circuit?
6 AWG
What is the minumum size required for the copper EGC that is sized 250 AWG aluminum
6 AWG
What is the minimum-size equipment grounding conductor required for a 50-horsepower, 460-volt, 3-phase motor that has a non-time-delay fuse for a branch-circuit short-circuit and ground-fault protective device rated at 200 amperes as permitted in 430.52(C)(1), Table 430.52, and Exception No. 1 to 430.52(C)(1)? Note the branch circuit conductors required for the motor are sized at 4 AWG copper based on Section 430.22.
6 AWG copper Section 250.122 indicates that in no case does the equipment grounding conductor have to be larger than the circuit conductors.
What is the minimum-size aluminum equipment grounding conductor required for a feeder that is protected by a circuit breaker rated at 4,000 amperes?
750 kcmil
Metal-clad cable Type MC is suitable for use as an equipment grounding conductor in accordance with which of the following?
Any of these: a. It contains an insulated or uninsulated EGC in compliance with Section 250.118(1) b. The combined metallic sheath and uninsulated equipment grounding/bonding conductor of interlocked metal-tape-type MC cable that is listed and identified as an EGC c. The metallic sheath or the combined metallic sheath and EGCs of the smooth or corrugated-tube-type MC cable that is listed and identified as an EGCa.
List the three elements that an effective ground-fault return path is required to perform in order to maintain and provide adequate safety.
Be electrically continuous, have sufficiently low impedance to limit the voltage to ground and to facilitate the operation of the circuit protective devices, have the capacity to conduct safely any fault current likely to be imposed on it.
Bonding of electrical equipment is important for a grounded system because it accomplishes all but which of the following?
Eliminates voltage gradients in the Earth and provides grounding connection to the Earth. bonding is important because it establishes a connection between metal equipment, it establishes an effective ground-fault current path, it establishes conductivity between metal equipment, and it establishes continuity between metal equipment.
Which of the following is or are a performance function(s) provided by equipment grounding conductors?
Facilitates overcurrent device operation, Performs bonding, Performs grounding
Equipment grounding conductors can be a wire type that is insulated, covered, or bare and can also be in the form of all but which of the following wiring methods?
Mineral Insulated cable (Steel Alloy Type). Note: Only the copper sheath of type MI cable is suitable as an equipment grounding conductor. References are 250.118(9) and the UL White Book in category PPKV.
Current could be present in the equipment grounding conductor under which of the following conditions?
Only during a ground fault event to facilitate overcurrent device operation
Which part of Article 250 provides specific electrical bonding requirements?
Part V
? requires that metal water piping and other metal piping systems installed within or attached to buildings or structures be bonded.
Section 250.104
Which of the following is not recognized in the Code as an acceptable method of attaching bonding jumpers to circuits and equipment?
Sheet metal screws and solder connections. Acceptable connections include: 1. Connections that are part of a listed assembly 2. Exothermic welding 3. Listed clamps 4. Machine screw fasteners that engage not less than two threads or are secured with a nut 5. Pressure connectors listed as grounding and bonding equipment 6. Terminal bars
Equipment grounding conductors of multi-conductor cable assemblies are permitted to be sectioned if the combined circular mil area meets the minimum sizes specified in ?
Table 250.122
Which NEC table is used to establish the minimum size required for wire-type equipment grounding conductors
Table 250.122
Where a building or structure is supplied by a feeder or branch circuit, the bonding jumper to the water piping system(s) is required to be sized according to ? , based on the size of the feeder or branch circuit that supplies the building or structure.
Table 250.66
Flexible metal conduit is not permitted to be used as an equipment grounding conductor except when it meets which of the following conditions
a. The circuit contained in the conduit is protected by an overcurrent device rated 20 A or less b. The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground-fault current path does not exceed 6' c. The conduit is terminated in listed fittings
When two conductive parts are connected together to establish electrical continuity and conductivity between them, they are ? .
bonded
The metal water piping system is permitted to be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where large enough, or to one or more grounding ?
electrodes
Where loosely jointed metal raceways are used and, especially where there are expansion joints or telescoping sections of raceways, the National Electrical Code requires that they be made electrically continuous by the use of a(n) ? or other means.
eqipment bonding jumper
A(n) ? is generally required to connect the grounding terminal of a grounding-type receptacle to a grounded box.
equipment bonding jumper
What is the minimum-size copper bonding jumper required for an interconnected metal building frame if the service is rated 1,000 amperes and supplied by two parallel 600 kcmil copper conductors for each ungrounded service phase conductor?
3/0 AWG
If multiple branch circuits (20-, 30-, 40-, 50-, 60- and 100-ampere) are installed in a single three-inch conduit, and the largest circuit is protected at 100 amperes, what is the minimum-size copper equipment grounding conductor required in the raceway?
8 AWG
Equipment grounding conductors in sizes larger than 6 AWG are permitted to be identified by all of which of the following methods?
a. Coloring the insulation or covering green at the termination b. Marking the insulation with green tape or green adhesive labels at terminations c. Stripping the insulation or covering from the entire exposed length
Effective bonding of metal parts is required to maintain effective continuity from the service to the ?
a. farthest outlet supplied by the system b. first panelboard enclosuret c. first receptacle in the branch circuit d. first system overcurrent device
A(n) ? is the connection between two or more portions of the equipment grounding conductor.
equipment bonding jumper
According to the NEC Style Manual, the phrase "likely to become energized" is best described by which of the following?
failure of insulation on
Liquidtight flexible metal conduit in sizes one and one-half inches and larger is suitable for use as an equipment grounding conductor if all the conditions in Section 250.118(6) a. through e. are met.
false
Reducing washers are not suitable for non-service bonding in circuits over and under 250 volts to ground.
false
Fittings for wiring methods such as electrical metallic tubing and rigid metal conduit are required to be ? .
listed
A ? is a conductor installed on the supply side of a service or separately derived system to ensure the required electrical conductivity between metal parts required to be electrically connected
supply-side bonding jumper
A system bonding jumper is the connection between the grounded conductor and the equipment grounding conductor or ? , or both, at a separately derived system.
supply-side bonding jumper
A single (wire-type) equipment grounding conductor is permitted to be used as both an equipment grounding conductor and a grounding electrode conductor for a separately derived system under certain specific conditions.
true
An equipment bonding jumper from a metal box to a grounding-type receptacle is not necessary for a self-grounding type receptacle.
true
Equipment grounding conductors must generally be installed with the conductors of an AC circuit by installing them in the same raceway, cable, or trench except in rare cases when EGCs are permitted to be installed according to Section 250.130(C).
true
Standard boxes with concentric and eccentric knockouts are listed for bonding and use in circuits over and under 250 volts phase to ground.
true
The grounded conductor of each separately derived system shall be bonded to the nearest available point of the metal water piping system(s) in the area served by the separately derived system.
true
Where Type SE cable is used to supply a 240-volt water heater, the bare conductor in the cable assembly is permitted as the required equipment grounding conductor.
true
Where the ungrounded conductors for a 225-ampere feeder are increased in size from 250 kcmil copper to 800 kcmil copper due to length, what is the minimum-size copper equipment grounding conductor required for the circuit?
3/0 Divide the required size into the adjusted size to establish a multiplier. 800 ÷ 250 = 3.2 Multiply the cm area (from Table 8) of the required EGC (4 AWG copper in this case) by the multiplier and arrive at the minimum cm area as adjusted proportionately. 3.2 × 41740 = 133,568 cm Insert that value back into Table 8 and arrive at the adjusted minimum-size equipment grounding conductor required for the circuit. 3/0 is the next larger size.
What is the minimum-size aluminum equipment bonding jumper required for a range receptacle installed in a metal box where the branch circuit is protected by a 60-ampere circuit breaker?
8 AWG
Which of the following methods is not suitable for establishing bonding connections for circuits over 250 volts phase to ground?
A locknut on the outside and a bushing on the inside of metal enclosure
Which of the following is not a condition that relates to flexible metal conduit being suitable as an equipment grounding conductor?
The conduit is used to connect equipment in which flexibility is necessary to minimize the transmission of vibration from equipment or to provide flexibility for equipment that requires movement after installation.
An equipment bonding jumper is permitted to be installed either inside or outside of a raceway or enclosure.
true
Cable trays are permitted to be used as equipment grounding conductors where they meet the requirements in 392.10 and 392.60.
true
Equipment grounding conductors are the conductive path(s) installed to connect normally non-current-carrying metal parts of equipment together and to the system grounded conductor or to the grounding electrode conductor, or both.
true
Where concentric, eccentric, or oversized knockouts are encountered in circuits over 250 volts phase to ground, one of the bonding methods in Section 250.92(B)(2) through (4) must be applied to ensure the required continuity and conductivity.
true
Where more than one raceway enters or leaves a switchboard, pull or junction box, or other equipment, it is permissible to use a single conductor to bond these raceways to the equipment where sized appropriately.
true
The armor of Type AC cable is suitable as an equipment grounding conductor without the inclusion of an insulated copper equipment grounding conductor in the cable assembly if used with listed fittings.
true. Make the point about using listed fittings for which the wiring method has been evaluated [NEC 110.3(B)]. Listed fittings have been evaluated for grounding
If a 100-ampere feeder is installed to a separate building, and the size of the circuit conductors is increased from 1 AWG copper to 750 kcmil copper due to excessive voltage drop, what is the minimum-size copper equipment grounding conductor required for the circuit?
3/0 AWG (same as Q 12 of chapter 8)
