Unit 4: Cables

Type MC cables containing no more than four conductors, size 10 AWG or smaller, must be secured within how many inches of every box, according to article 330,30?

12 inches.

according to article 320.30 Type AC cable must be secured within how many inches of every box, cabinet, or fitting?

12 inches.

according to article 334,30 Nonmetallic-sheathed cable secured to the box must be secured within how many inches of every box, cabinet, or fitting?

12 inches.

Nonmetallic-sheathed cable passing through holes or slots in metal framing must be protected by what?

by listed bushings or grommets covering all metal edges and securely fastened in the opening prior to cable installation, Article 300,4,B,1

if one and a quarter on an inches setback is not possible for Cables installed parallel to framing members, the cable must be protected from penetration by nails or screws. According to 300,4,D, Exception Number 3 how can we protect the wires.

we need to use one sixteenth, thick, steel plate, sleeve, or equivalent.

Nonmetallic-sheathed cable must be supported and secured at intervals not exceeding how many fits? according to article 334,30

4 and half, fit

what is Type MV cable? and what do you know about it?

Medium-Voltage Cable, 1, MV is a solid dielectric insulated cable rated 2001 volts or higher 2, According to article 328.12, MV cable shall not be used where exposed to direct sunlight, unless identified for the use 3, cables must have copper, aluminum, or copper-clad aluminum conductors and shall comply with Table 310.104,C, and Table 310.104,D, or Table 310.104,E, 4, Conductor ampacity is found in 310.60, unless the cable is installed in a cable tray, in which case the ampacity shall be determined in accordance with 392.80,B

According to article 320,24, how do we find the bending radius of the type M,C cable?

Type AC cable (interlocked-type or corrugated sheath) has a bending radius of five times the external diameter of the metallic sheath

According to article 330,24,B, how do we find the bending radius of the type M,C cable?

Type MC cable (interlocked-type or corrugated sheath) has a bending radius of seven times the external diameter of the metallic sheath

According to article 320,40, All armor termination points of AC cable shall have what? to protect the wires from abrasion.

a fitting

Where the bored hole is less than one and a quarter of the inch from the edge, the cable or raceway-type wiring method shall be protected by what?

by a steel plate(s) or bushing(s), to prevent penetration by screws or nails, Article 300,4,A,1

Interlocking-armor Type MC cable does not require an equipment grounding conductor, truth or false ?

false, Interlocking-armor Type MC cable requires an equipment grounding conductor.

According to article 300,15,C., Cables entering or exiting conduit (or tubing) used for support or protection against physical damage require what to prevent cable abrasion

fittings on the conduit

According to article 300,4,A,1, Holes must be bored so that the edge of the hole is at least how many inches from the nearest edge of the wood member ?

one and a quarter of an inch,

Cables installed parallel to framing members, studs, joists, etc., or installed parallel to furring strips shall be installed and supported so that the nearest outside surface of the cable is at least how many inches from the nearest edge of the framing member or furring strip where nails or screws are likely to penetrate

one and a quarter on an inch

what is The largest hole that can be bored in a 3 and half inches, wood stud without using a steel plate, clip or sleeve?

one inch

Joist or stud spaces, used for environmental air-handling purposes, shall not contain what kind of cable ?

nonmetallic-sheathed cable that runs along the long dimension

According to article 200,7,C,1, A cable assemblies white or gray conductor can be used as a switch loop leg in single-pole, three-way, and four-way switch installations, even though it is an ungrounded, hot conductor truth or false ?

truth

According to article 200,7,C,1, The white or gray conductor shall not be used as a return conductor from the switch to the outlet truth or false ?

truth

Type AC cable must be supported and secured at intervals not exceeding how many fits? according to article 320,30

4 and half, fit

According to article 320,23,A , 330,23, and 334,23, Attics and roof spaces not accessible by permanent stairs or ladders require protection only within how many fit of the nearest edge of the scuttle hole or attic entrance

6 fit

Type MC cable must be supported and secured at intervals not exceeding how many fits? according to article 330,30

6 fit.

according to article 314,17,C Exception., Nonmetallic-sheathed cable not secured to a single-gang box must be secured within how many inches?

8 inches.

If needed can we use white color wire as an ungrounded (hot) conductor if it is part of a cable assembly if so how do we do it?

According to article 200,7,C,1, The white conductor can be used as an ungrounded, hot conductor if it is part of a cable assembly, The insulation must be permanently identified as an ungrounded conductor by marking tape, painting, or other effective means at its termination and at each location where the conductor is visible and accessible

does Section 300,22 apply to dwelling unit joist or stud spaces where wiring passes perpendicular to the long dimension of such spaces?

No, 300,22,C, Exception

Can Nonmetallic-sheathed cable passing through a floor?

No, According to article 334,15,B, Nonmetallic-sheathed cable passing through a floor must be enclosed in rigid or intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, Type RTRC marked with the suffix-XW, or other approved means that extends at least 6 inches above the floor.

what is Type MI cable? and what do you know about it?

1, cable is a manufactured assembly of conductors insulated with a highly compressed refractory mineral insulation and enclosed in a liquidtight and gastight continuous copper or alloy steel sheath 2,The radius of the inner edge of any bend shall not be less than five times the external diameter of the metallic sheath for cable that is not more than Three quarter of an inch of external diameter, but not more than 1 inch. 3, Where Type MI cable terminates, a seal shall be provided immediately after stripping to prevent the entrance of moisture into the insulation. Each conductor extending beyond the sheath must be provided with an insulating material

In hollow spaces, vertical shafts, and ventilation or air-handling ducts, electrical installations must not substantially increase the possible spread of fire or products of combustion, according to article 300,21 what steps can be taken to prevent that.

Electrical installation openings that penetrate into or through fire-resistant-rated structures walls, partitions, floors, ceilings, etc. must be firestopped using approved methods that maintain the fire resistance rating.

A widely accepted practice is to identify 3-phase ungrounded, hot conductors as what color

black, red, and blue in 208,/,120 volt, 4-wire, wye-connected systems; and brown, orange, and yellow in 480,/,277 volt, 4-wire, wye-connected systems.

Cables, installed in a groove, covered by wallboard, paneling, carpeting, etc., shall be protected by what?

one sixteenth, thick steel plate, sleeve, or equivalent, or by at least one and a quarter on an inch,. free space for the full length of the groove in which the cable is installed Article 300,4,F

What table shows; Cover measurement commences at the top surface of any direct burial wiring method conductor, cable, conduit, or other raceway and ends at the closest point of the finished grade's top surface including concrete.

table, 300.5