Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
ELECTRICAL INSPECTION, DIAGNOSIS, REPAIR
ACCURACY vs PRECISION of MEASUREMENTS
AFCIs ARC FAULT CIRCUIT INTERRUPTERS
ALUMINUM SECs & WIRING
ALUMINUM WIRING HAZARDS & REPAIRS
AMPS & VOLTS DETERMINATION
AMPACITY - the LIMITING FACTOR
APPLIANCE EFFICIENCY RATINGS
BACKUP ELECTRICAL GENERATORS
BACK-WIRED ELECTRICAL DEVICES
BOOKSTORE - ELECTRICAL
BUILDING SAFETY HAZARDS GUIDE
Cadet & Encore Heater Recall
CIRCUIT BREAKER FAILURE
CIRCUIT BREAKER SIZE for A/C or HEAT PUMP
Classified CIRCUIT BREAKER WARNING
CORROSION in ELECTRICAL PANELS
CORROSION & MOISTURE SOURCES in PANELS
CUTLER HAMMER PANEL FIRE
DEFINITIONS of ELECTRICAL TERMS
DIRECTORY OF ELECTRICIANS
DMM Digital Multimeter HOW TO USE
ELECTRIC METERS & METER BASES
ELECTRIC MOTOR DIAGNOSTIC GUIDE
ELECTRIC MOTOR OVERLOAD RESET SWITCH
ELECTRIC PANEL AMPACITY
ELECTRIC PANEL INSPECTION
ELECTRIC PANEL MOISTURE
Electric Power Frequency Table
ELECTRICAL DISTRIBUTION PANELS
ELECTRICAL GROUND SYSTEM INSPECTION
ELECTRICAL SERVICE DROP
ELECTRICAL SERVICE ENTRY WIRING
EMF RF FIELD & FREQUENCY DEFINITIONS
FEDERAL PACIFIC FPE HAZARDS
FIRE SAFETY Checklist, CPSC
GFCI PROTECTION,Testing GFCIs AFCIs
HEATING COST FUEL & BTU COST TABLES
HEAT TAPE USAGE GUIDE
Hertz - Definitions of KHz MHz GHz THz
KNOB & TUBE WIRING
LIGHTING, EXTERIOR GUIDE
LIGHTING, INTERIOR GUIDE
LIGHTNING PROTECTION SYSTEMS
LOW VOLTAGE BUILDING WIRING
LOW VOLTAGE TRANSFORMER TEST
MAIN ELECTRICAL DISCONNECT
MAIN DISCONNECT AMPACITY
MOISTURE SOURCES in PANELS
MURRAY SIEMENS Recall
PHOTOVOLTAIC POWER SYSTEMS
PUSHMATIC - BULLDOG PANELS
REMOTE ELECTRIC POWER, PHOTOVOLTAIC
RUST in ELECTRICAL PANELS
SAFETY for ELECTRICAL INSPECTORS
SE CABLE SIZES vs AMPS
SIEMENS MURRAY Recall
UNDERGROUND SERVICE LATERALS
VOLTS / AMPS MEASUREMENT EQUIP
VOLTAGE MEASUREMENT METHODS
WIND ENERGY SYSTEMS
WIND TURBINES & LIGHTNING
ZINSCO SYLVANIA ELECTRICAL PANELS
How & where to route electrical wires when hooking up an electrical receptacle or wall plug or electrical outlet.
This article series describes how to choose, locate, and wire an electrical receptacle in a home. Electrical receptacles (also called electrical outlets or "plugs" or "sockets") are simple devices that are easy to install, but there are details to get right if you want to be safe.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
[Click to enlarge any image]
The electrical circuit wire must be properly routed and secured between the electrical panel and the receptacle location, and must be properly secured at the junction box that is to hold the electrical receptacle.
We secure wires at intervals specified by the electrical code so that it doesn't sag, hang, pull on itself, and become damaged or unsafe. The two sketches below, courtesy of Carson Dunlop, show examples of routing electrical circuit wires through a wood stud wall and through a wall supported by metal studs.
Wires running in walls anywhere from floor level to seven feet above the floor (U.S.) or five feet above the floor (Canada) must be protected from nails driven through walls. Our photo (left) illustrates a 6-inch NS-2 Nail Stop produced by Simpson Strong-Tie. Simpson Strong-Tie describes these as Protecting Shield Plate Nail Stoppers.
We are showing the side of the nail-stop that will be in contact with the stud surface when it it tapped into place, providing 5 3/8" of 16-gauge steel that will protect electrical wiring (or plumbing pipes) from punctures by nails or screws driven into the wall when this nail stop has been placed on a wall stud over the point through which an electrical wire (or pipe - see CONDENSATE DRAINS) has been passed.
Nail stops by Simpson Strong-Tie are made of 16-gauge steel, include sharpened protrusions that allow the plate to be tapped into place on stud surfaces, and are sold in 1 1/2" or 5-inch widths and in lengths ranging from 2 1'2" to 16 5/16". The most commonly-seen nail stop we encounter is the NS1 3-inch model.
Simpson Strong-Tie provides a Code Compliant Repair and Protection Guide that describes the company's range of protective and reinforcing steel devices to comply with the various building code requirements to protect wiring and plumbing from nail and screw fastener damage.
We also don't route wires too close to places where the wires can be damaged by heat from a heating appliance or chimney, flooded, etc. as you'll see depicted in the two Carson Dunlop sketches below. Thanks to Steve for pointing out erroneous illustration link details, now fixed.
The illustration at left shows the typical wiring of an electrical outlet or "receptacle", courtesy of Carson Dunlop Associates.
Watch out: Electrical components in a building can easily cause an electrical shock, burn, or even death.
Even when a hot line switch is off, one terminal on the switch is still connected to the power source.
Before doing any work on the switch, the power source must be turned off by setting a circuit breaker to OFF or removing a fuse.
Routing Electrical Wiring Through Metal Studs
Reader Question: NMC cable pulled through metal studs without proper protection
Having a hard time with seller who framed the basement with metal studs, and pulled ROMEX through with no grommets or bushings. Tried to explain that that Metal studs are SHARP and will eventually cut through the romex and short it (POW !), or make the studs live (ouch) I will trade pictures with you if you have some that will go with these.
These photographs (below) are from the inspection. - B.S., Professional home inspector, 7/27/2014
There are simple plastic snap-in wiring grommets or "bushings" that offer that protection and that would have been easy to install at the time of wiring and that can doubtless be retrofit now though if the installer has to cut the bushings to insert them around the existing wiring s/he will need to check with the acceptability of that bushing modification by callling the local electrical inspector for the jurisdiction.
Carson Dunlop Associates sketch of wiring passing through a metal stud (used with permision) just above in this article discusses this very topic.
The photo at left, courtesy Greenlee Corporation (www.greenlee.com) illustrates a plastic bushing PN 712A-1000 designed to protect wiring where it passes through metal studs.
Wiring through metal studs is a very common procedure as we know. In addition to using the larger holes shown in your photos, there is a punching tool (a metal stud punch) and plastic grommets to fit the punched holes so that wires can be run exactly where needed.
I'll post your photos along with images of the proper plastic bushings and send you the link.
U.S. Electrical Code for Wiring NMC through Metal Studs
Meanwhile, if we are reduced to having to cite code to tell some goofus what she or he ought to have known and done in the first place, see these NEC sections:
Canadian Electrical Code for Wiring NMC through Metal Studs
Canadian Inspectors needing code citations for protection of non-metallic-sheathed wiring will want to see the 12-19-11 Ontario Electrical Safety Code Bulletin
"Bulletin 12-19-11 Non-Metallic-Sheathed Cables (NMSC) wiring methods, [PDF] Rules 2-034, 2-200, 4-004, 12-500 to 12-526, 12-3012 and 12-3022(3)", May 2012, - retrieved 7/27/4, original source http://www.esasafe.com/assets/files/esasafe/pdf/Sample_Bulletins/12-19-11.pdf. It is interesting that Rule 12-520 does not permit cables to be fished where metal joists, metal top or bottom plates, or metal studs are used.
Thanks to Mike Holt for help with this topic.
Sources of wiring protection for metal studs
Not only does the triple lock mechanism keep these bushings locked to 12 or 24 gauge metal studs but also prevents damage or abrasion from happening when bundling up to 10 electrical cables at once. These insulation rings are UL listed, CSA Certified and come with a 1 year warranty.
Unsafe & Improper Electrical Wire Material & Routing - Zip Cord or Extension Cord
Our photo (left) shows an electrical receptacle mounted just about 2" above the finished floor - which is ok except for the ADA requirements, but that zip cord wiring that is run into the wall is improper, unsafe, and a fire hazard.
Continue reading at NAIL STOPS to PROTECT WIRES or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References