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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 Table
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
Electrical wire clearance distances, spacings, when wiring up a wall receptacle (plug or "outlet"), switch or similar device. Here we explain how far electrical wiring should be kept from hot HVAC ducts, pipes, the surface of wall studs or ceiling joists, and similar restrictions. 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. Page top illustration courtesy Carson Dunlop Associates.
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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.
Also you'll note in the two Carson Dunlop sketches just below that wires need to be routed through the center of wall studs, ceiling or floor joists, or if there is less than 1 1/4-inches of clear space between the wire opening in the stud or joist and the joist face you must use a nail plate or NAIL STOPS(shown below) to protect the wire from penetration from a nail or screw that someone may drive into the stud or joist later.
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 catalogs these nail stops as Protecting Shield Plate Nail Stoppers.
Details about using these steel plates to protect electrical wire (and also pipes) in buildings are at NAIL STOPS to PROTECT WIRES or select a topic from the More Reading links shown below.
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: what is the minimum height that indoor house wiring must be above the ground or floor level?
When running wire for a basement, is there a min height the wires must be off the ground? Not the outlet box, but the wire running through the joists. Justin Sheppard
No, Justin. But if there is the slightest danger that wires will be nicked by someone driving a nail into a stud though which the wires are run be sure to use steel plates to protect the wire where it passes through the studs. Simple nail plates are available at any building supplier.
Question: how to fix loose electrical receptacles in a ceramic tile or glass mirror wall wall
Is there a way to repair electrical outlets on finished (glass and ceramic tile) walls that were not installed properly without damaging the tile? The outlets and the covers pull away from the wall when the electrical cord plug in removed?
Question: how do I increase the projection of outlets into a room so I can add a kitchen backsplash
I am unable to find instructions on how to increase the projection into the room of existing electrical outlets so that I can tile the kitchen backsplash and have the outlets be at the appropriate depth for use and safety. Do I move forward the box to which the outlet is screwed and if so how? - Anne 3/22/12
Reply: use electrical box extenders - shop for an "electrical box extension" of the proper thickness
Building suppliers like Home Depot and also your electrical supply house sell "box extenders" in varying thicknesses, made of plastic, code approved, for the purpose you describe. The electrical box extender is sized and shaped to match the electrical receptacle box to which it is to fit.
By removing the electrical receptacle from its mount on the existing box, the box extender is fit as a sort of large rectangular plastic washer, mounting between the existing box edge or surface and the mounting ears of the receptacle or switch.
Electrical box extensions are sold in plastic and steel and in thicknesses from about 1/8" up to an inch or even more. The plastic electrical "gang box extension" shown at above left is produced by Arlington Industries but there are several manufacturers. Just choose an electrical box extender that brings your receptacles far enough forward to suit the thickness of the kitchen backsplash or tile.
Watch out: don't try a makeshift substitute using washers or junk - that's an improper and unsafe repair, leaving a gap around the electrical box sides.
While I was changing a failed plug I noticed that the box was too deep. I looked into extenders, and plastic ones (Arlington BE1) are less expensive. Are CSA approved plastic box extenders code compliant for homes? - Gary 7/19/12
Question: electrical outlet height requirements
I was looking at some height requirements on electrical outlets this is a very informational site.
Jerm, in the article above at HEIGHT above FLOOR for OUTLETS we give the data you want. Let me know if anything is unclear.
Question: what do I do with the screws to which no wire is connected on a conventional "plug" (wall receptacle)?
At the end of a circuit, I'm only using 2 of the 4 screws on a conventional plug. What should I do with the 2 unused screws? Should they be screwed all the way in? Or left partially unscrewed? Or does it matter? - Chris Rasko 7/8/12
Question: armor around wire through concrete?
I am running a new 15A outlet into the back of a bookcase in a 50 year old house with updated electrical. The wire runs out the back of the retrofit box and down through the concrete foundation into the crawlspace to a wire I plan to splice into. Do I need to put armor around the wire run through the foundation? It goes through open air for about 2 feet and there is no way to secure it to anything.
You need to look at the type and rating of the electrical wire to determine if it is permitted to bury it in concrete or not.
Questions & answers or comments about how to install and wire electrical outlets or receptacles in buildings.
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.
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