PEC CHAPTER 3 WIRING METHODS AND MATERIALS Flashcards
APPROVED TYPE OF WIRING METHOD BY P.E.C.
a) Conductors on Insulator Method: (2)
- Open wiring on insulator - installed exposed*
2. Concealed knob and tube work - installed hidden by portion of the building*
APPROVED TYPE OF WIRING METHOD BY P.E.C.
b) Cable Wiring Method: (11)
- Armored (BX) cable*
- Metal-clad cable
- Mineral insulated metal sheathed cable
- Non-metallic sheathed cable
- Shielded non-metallic sheathed cable
- Service entrance cable
- Underground feeder & branch circuit cable
- Power and control tray cable
- Flat conductor cable
- Medium voltage cable
- Integrated gas spacer cable
APPROVED TYPE OF WIRING METHOD BY P.E.C.
c) Raceway Method (20)
- Intermediate metal conduit (IMC)*
- Rigid metal conduit (RMC)*
- Rigid non-metallic conduit (PVC)*
- Electrical metallic tubing (EMT)*
- Flexible metallic tubing (FMT)*
- Liquid-tight flexible metallic tubing
- Liquid-tight flexible non-metallic tubing
- Metallic surface raceway*
- Wooden surface raceway*
- Non-metallic surface raceway*
- Underfloor raceway
- Cellular metal floor raceway
- Cellular concrete floor raceway
- Wireways*
- Busways*
- Cable trays*
- Cablebus
- Flexible metallic conduit*
- Electrical non-metallic tubing
- Multi-outlet assembly
APPROVED TYPE OF WIRING METHOD BY P.E.C.
- The most commonly used methods done by practitioners
Open wiring on insulator - installed exposed* Concealed knob and tube work - installed hidden by portion of the building* Armored (BX) cable* Intermediate metal conduit (IMC)* Rigid metal conduit (RMC)* Rigid non-metallic conduit (PVC)* Electrical metallic tubing (EMT)* Flexible metallic tubing (FMT)* Metallic surface raceway* Wooden surface raceway* Non-metallic surface raceway* Wireways* Busways* Cable trays* Flexible metallic conduit* Open wiring on insulator - installed exposed*
WIRING METHODS
Conductors of Different Systems
a) 600 Volts, Nominal, or Less - ____ and _____shall be permitted to occupy the same equipment wiring enclosure, cable, or raceway. All conductors shall have an insulating rating equal at least the ________ applied to any conductor.
b) Over 600 Volts Nominal - Conductors rated over 600V, ____occupy the same equipment wiring enclosure, cable, or raceway unless permitted. The following listed are permitted to be in the same path:
- Secondary wiring to electric-discharge lamps of 1000 volts or less.
- Primary leads of electric-discharge lamp ballast.
- Excitation, control, relay, and ammeter conductors used in individual motor or starter.
- Motor, switchgear and control assemblies, and of similar equipment conductors.
- In manholes, cond. of each system is permanently & effectively separated from other system.
AC circuit
DC conductors
maximum circuit voltage
shall not
WIRING METHODS
Protection against Physical Damage
- Either exposed and concealed locations, installed in joists, rafters, or wood members. Holes must not less than ___(mm) of the nearest edge. Screw penetrations, nails by a steel plate or bushing shall be at least ___ (mm) thick.
a) Cable and Raceways Through Wood Members
1. Bored Holes
2. Notches in Wood
b) Nonmetallic-Sheathed Cables, Electrical Nonmetallic Tubing through Metal Framing Members
1. Nonmetallic-Sheathed Cable - protected by listed bushing, grommets covering all metal edges.
2. Nonmetallic-Sheathed Cable and Electrical Nonmetallic Tubing
c) Cables Through Spaces Behind Panels Designed to Allow Access
d) Cables and Raceways Parallel to Framing Members and Furring Strips
e) Cables and Raceways Installed in Shallow Grooves
f) Insulated Fittings - Raceways containing ungrounded conductors 22 mm2 or larger enter a cabinet, enclosure, or raceway, protected by substantial fitting with a smoothly rounded insulating surface.
30 mm
1.60 mm
WIRING METHODS
Protection against Physical Damage
a) Cable and Raceways Through Wood Members
- Bored Holes
2. Notches in Wood
WIRING METHODS
Protection against Physical Damage
b) Nonmetallic-Sheathed Cables, Electrical
Nonmetallic Tubing through Metal Framing Members
__________ - protected by listed bushing, grommets covering all metal edges. and Electrical Nonmetallic Tubing
Nonmetallic-Sheathed Cable
WIRING METHODS
Protection against Physical Damage
Insulated Fittings - Raceways containing _____ conductors _______(mm2) or larger enter a cabinet, enclosure, or raceway, protected by substantial fitting with a smoothly rounded insulating surface.
ungrounded
22 mm2
WIRING METHODS
Mechanical and Electrical Continuity - Conductors
Conductors in raceways shall be continuous between outlets, boxes, devices, and so forth. There _____ splice or tap within a raceway unless permitted.
In multiwire branch circuits, the continuity of a grounded conductor __________ on device connections such as lampholders, receptacles, and so forth, where the removal of such devices would interrupt the continuity.
shall be no
shall not depend
WIRING METHODS
Length of Free Conductors at Outlets, Junctions, and Switch Points
- At least ____(mm) of free conductor from the point in the box to the raceway or cable sheath at each outlet, junction, and switch point for splices.
150 mm
WIRING METHODS
Wiring in Ducts, Plenums, and Other Air-Handling Spaces
- The following are listed types of material that are permitted for wirings in ducts, plenums, air-handling spaces:
- Type MI cable, Type MC cable without non-metallic covering.
- EMT, FMT, IMC, or RMC without non-metallic covering.
WIRING METHODS
Panels Designed to Allow Access
- Cables, raceways, and equipment installed _____panels designed to allow access, including suspended ceiling panels, shall be arranged and secured so as to allow the ______ of panels and ____ to the equipment.
behind
removal
access
WIRING METHODS
Requirements for Over 600 Volts, Nominal Conductor Bending Radius:
Nonshielded Conductors - The bending radius shall not be less than _____ the overall diameter.
8 times
WIRING METHODS
Requirements for Over 600 Volts, Nominal Conductor Bending Radius:
Shielded or Lead Covered Conductor - The bending radius shall be _______ the overall diameter.
12 times
WIRING METHODS
Requirements for Over 600 Volts, Nominal Conductor Bending Radius:
Multiconductor or Multiplexed Single Conductor - ______ the diameter of individual conductor or ____ the overall diameter, whichever is greater.
12 times
7 times
CONDUCTORS FOR GENERAL WIRING
Stranded Conductors
- The conductors installed in raceways, size _____(mm2) and larger shall be stranded.
8.0 mm2
CONDUCTORS FOR GENERAL WIRING
Conductors in Parallel
- Conductors that are ____(mm2) and larger (aluminum, copper-clad aluminum, copper) are permitted to be in parallel. Parallel conductors in each phase, polarity, neutral/grounded circuit conductors shall comply with the ff:
- Be the same length
- Have the same conductor material
- Be the same cross sectional area of the conducting material
- Have the same insulation type
- Be terminated in the same manner
50 mm2
CONDUCTORS FOR GENERAL WIRING
Shielded
- Solid dielectric insulated conductors operated above ______V in permanent installations shall have an ozone resistant insulation and shall be shielded.
2000 volts
CONDUCTORS FOR GENERAL WIRING
Locations
a. ) Insulated conductors and cables of any type can be used in _______.
b) Dry and Damp Locations - Insulated conductors and cables used in dry and damp locations shall be of Types (21)
c) Wet Locations - Conductors used in wet locations shall be:
d) Locations Exposed to Direct Sunlight - Insulated conductors or cables exposed to direct rays of the sun shall be of types that are _______.
dry locations
FEP, FEPB, MTW, PFA, RHH, RHW, RHW-2, SA, THHN, THW, THW-2, THHW,
THHW-2, THWN, THWN-2, TW, XHH, XHHW, XHHW-2, Z, or ZW
- Moisture-impervious metal sheathed
- Types MTW, RHW, RHW-2, TW, THW, THW-2, THHW, THHW-2, THWN, THWN-2,
XHHW, XHHW-2, ZW
sunlight resistant
CONDUCTORS FOR GENERAL WIRING
Marking
Required Information - All conductors and cables shall be marked with the following:
- The maximum rated voltage.
- Proper type of letter or letters.
- The manufacturer’s name, trademark, or distinctive marking of manufacturer.
- Size in millimeter square or millimeter diameter.
- Cable assemblies where the neutral conductor is smaller than the ungrounded conductors.
CONDUCTORS FOR GENERAL WIRING
Marking
Method of Marking
Surface Marking - The size in mm2 or mm diameter shall be repeated at intervals not exceeding -______(mm). All other markings shall be repeated at intervals not exceeding _____(mm)_.
- Single-conductor and Multiconductor rubber and thermoplastic insulated wire
- Nonmetallic-sheathed cable
- Service-entrance cable
- Underground feeder and branch-circuit cable
- Tray cable
- Irrigation cable
- Power-limited tray cable
- Instrumentation tray cable
600 mm
1000 mm
CONDUCTORS FOR GENERAL WIRING
Marking
Method of Marking
Metal-covered multiconductor cables shall employ a _______.
marker tape
CONDUCTORS FOR GENERAL WIRING
Marking
Method of Marking
Tag Marking - Printed tag shall be attached to the coil, reel or carton for the following: (4)
- Mineral-insulated, metal-sheathed cable
- Switchboard wires
- Metal-covered, single-conductor cables
- Type AC cable
CONDUCTORS FOR GENERAL WIRING
Marking
Suffixes to Designate Number of Conductors - A type letter to indicate the number of conductors.
____- Two insulated conductors lay parallel with nonmetallic covering.
D
CONDUCTORS FOR GENERAL WIRING
Marking
Suffixes to Designate Number of Conductors - A type letter to indicate the number of conductors.
____- Assembly of two or more insulated conductors, twisted spirally with nonmetallic covering.
M
CONDUCTORS FOR GENERAL WIRING
Marking
Aluminum Conductor Material
- All aluminum alloy conductors shall be made of _________ electrical grade aluminum.
1. Solid Conductors - 8.0 mm2 (3.2 mm dia.), 5.5 mm2 (2.6 mm dia.), and 3.5 mm2 (2.0 mm dia.)
2. Stranded Conductors - 8.0 mm2 through 500 mm2 (Type RHH, RHW, XHHW, THW, THHW, THWN, THHN, service-entrance TYPE SE Style U and SE Style R)
AA-8000 series
CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES
Installation (Surface Type Enclosures)
a) Damp Locations - Enclosures installed in damp locations shall _________ and shall be placed with at least ___m airspace from the wall or of a supporting surface.
b) Wet Locations - Enclosures installed in wet locations shall be ________ and shall be placed with at least ____m airspace from the wall or of a supporting surface.
c) Position in Wall - Enclosures shall be installed in ________(3). Cabinets shall be installed so that the front edge is not set back of the finished surface for more than ___m.
prevent moisture from entering
6 mm
weatherproof
6 mm
walls of concrete, tile, or other noncombustible material
6 mm
CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES
Enclosures for Switches or Overcurrent Devices
- Shall not be used as junction boxes, auxiliary gutters, or raceways for feeder conductors unless ______ is provided for this purpose.
- The conductors shall not fill the wiring space at any cross section to more than ___%.
- Taps shall not fill the wiring space at any cross section to more than ___%.
adequate space
40%
75%
CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES
Construction Specifications (Cabinets, Cutout Boxes, and Meter Socket Enclosures)
a) Strength - The materials to be used shall have ample strength and rigidity to support the electrical components. If constructed of sheet steel, metal thickness shall not be less than ____(mm) uncoated.
b) Spacing - Spacings shall be _____ to provide ample room for the distribution of ________.
1.35 mm
sufficient
wires and cables
CABINETS, CUTOUT BOXES, AND METER SOCKET ENCLOSURES
Construction Specifications (Cabinets, Cutout Boxes, and Meter Socket Enclosures)
Spacing
- Base - Airspace of at least _____(mm) between the base of the device and the wall of any cabinet.
- Doors - There shall be airspace of at least ___(mm) between any live metal parts.
- Live Parts - Airspace of at least ____(mm) between the walls, back, and gutter partition. Spacing shall be increased to at least ____(mm) for voltages of ______V, nominal.
1.60 mm
25 mm
13 mm
25 mm
251 to 600
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
_____ shall not be used where conduits requires the use of locknuts/bushings on the side of the box.
Round boxes
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
______Are permitted only with open wiring on insulators, concealed knob-and-tube wiring, cabled wiring methods with entirely nonmetallic sheaths, flexible cords, and non metallic raceways.
Nonmetallic Boxes
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
__________ Capped-elbows and service-entrance elbows that enclose conductors 14 mm2 or smaller shall not contain splices, taps, or devices and have sufficient size to provide space.
Short -Radius Conduit Bodies
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
Supports for Enclosures:
a) _________ - Enclosures surface mounted shall be rigidly and securely fastened in place.
b) Structural Mounting- Rigidly supported either by directly using a ___________(3)
Surface Mounting
metal, polymeric, or wood brace.
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
Supports for Enclosures:
Structural Mounting (2)
- Nails and Screws
2. Braces
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
________Can be supported by flexible cord or conduits with length of 450 mm.
Pendant Boxes
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
______ Shall be 6 mm of back or ends of the enclosure.
Nails and Screws
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
Protected against corrosion and not less than 0.50 mm thick uncoated.
Metal Braces
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
Cross section not less than 25 mm x 50 mm.
Wood Braces
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
Must be identified to be suitable for use.
Polymeric Braces
OUTLET, DEVICE, PULL, AND JUNCTION BOXES; CONDUIT BODIES; FITTINGS; AND HANDHOLE ENCLOSURES
Enclosures shall be supported by clamps, anchors, or fittings
Mounting in Finished Surfaces