Ontario Electrical Code Junction Box Attic

Can Electrical Junction Box Be In Attic
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POST a QUESTION or COMMENT about how to install and wire electrical outlets or receptacles in buildings.

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Electrical codes generally require that all electrical devices, and the wiring connections to those devices, must be enclosed in an approved electrical box. Often known as a junction box, this metal or plastic box includes a cover to protect the wiring within and protect you from the wiring. How to wire a junction box in an attic (Part 1) is easy.when you know how. If youcome across a wire &/or romex cable that nee.

Guide to types of electrical receptacles (wall 'outlets' or 'wall plugs'):

How to choose the right type of electrical receptacle when adding or replacing a wall outlet in a building. Here we describe matching 15-Amp receptacles to 15-Amp circuits, 20-Amp receptacles to 20-Amp circuits, two-wire receptacles where no ground is present, GFCI and AFCI electrical receptacles, and the proper electrical box to hold and mount these devices.

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.

We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Choose the Proper Electrical Junction Box When Adding a Receptacle

The proper sized and type of junction box must be used to house the electrical receptacle, must be properly secured in the wall, and must be located at the proper height from the floor.
The National Electrical Code Article 314 contains complete details and tables of electrical box sizes in dimensions and cubic inches and should be consulted for complete accuracy because the actual size of the box required, in cubic inches, depends on the number of wires that will be within that enclosure.
We give some basic electrical box size examples just below.
If the junction box is too small you face several problems such as crowding which forces wires to be jammed and bent into the box, increasing the chance of a loose connection or damaged wiring, and worse, arcing.
If the clearance between the metal box and other live electrical parts is too small, arcs and short circuits could occur, as we depict in this sketch courtesy of Carson Dunlop Associates.

Article Contents

ELECTRICAL JUNCTION BOX TYPES

Table of Electrical Box Sizes vs Number of Wires Allowed

NEC Table 314.16 (A) Metal Electrical Boxes for Devices
Box Dimensions (Inches) & Trade Name	Minimum Cu. In.	Max # Conductors AWG 14	Max # Conductors AWG 12
3 x 2 x 1 1/2' Device Box	7.5 cu. in.	3	3
3 x 2 x 2 ' Device Box	10	5	4
3 x 2 x 2 1/2' Device Box	12.5	6	5
3 x 2 x 3 1/2' Device Box	18	9	8
4 x 2 1/2 x 1 1/2' Device Box	10.3	5	4
4 x 2 1/2 x 1 7/8' Device Box	13	6	5
4 x 2 1/2 x 2 1/8' Device Box	18	7	6
4 x 1 1/4' square	18	9	8
4 x 2 1/4' square	21	10	9
4 x 2 1/4' square	30.3	15	13

Notes to the table above

The National Electrical Code Article 314 contains complete details and tables of electrical box sizes in dimensions and cubic inches and should be consulted for complete accuracy because the actual size of the box required, in cubic inches, depends on the number of wires that will be within that enclosure.

This is an excerpt pertinent to wiring electrical receptacles and switches; other wire sized and applications are given in the source NEC.

NEC 314.16(B) Electrical Box Volume Required Per Conductor (wire)
Conductor size (wire size)	Free space within the box for each conductor
No. 14	2 cubic inches
No. 12	2.25 cubic inches
No. 10	2.5 cubic inches

Notes to the table above

This is an excerpt pertinent to wiring electrical receptacles and switches; other wire sized and applications are given in the source NEC.

Typical Electrical Boxes for Single Receptacles, Switches, or Splices

Typical electrical junction boxes used for receptacle installation to accommodates a single receptacle are 2' x 4' metal or plastic boxes of varying depth.

Choose a deeper box if you have more than the minimum number of wires entering & leaving the box or it will be over-crowded and may violate building electrical codes.

Below are an older style steel electrical boxes nailed to wood framing in a building. The box is carrying six wires in total: two 'hot', two neutral, and two grounds.

At above right in addition to aluminum wiring hazards the box is overcrowded.

See ALUMINUM WIRE REPAIR SPLICE SPACE.

Also

See ALUMINUM WIRING HAZARDS & REPAIRS.

It's likely to be permitted and safe to install a larger sized junction box than you need for an outlet or switch or wire splice, but you may need to purchase a special adapter-cover for the box in order to properly secure an electrical outlet therein. Installing a junction box that is too small is illegal and unsafe.

Can Electrical Junction Box Be In Attic

Typical 4-inch Electrical Boxes used for Single (or more often) Duplex Electrical Receptacles

Below-left we show a typical 4-inch metal junction box, and below-right a common and deeper plastic junction box.

Electrical junction boxes are required for all wall plugs ?

Reader Question: Do I really need an electrical box to put a new wall plug in ? - Thomas

Reply:

Yes, Thomas, electrical devices such as switches and receptacles (wall plugs) need to be mounted in a code-approved plastic or metal receptacle (box) for fire safety as well as to assure that the device is mechanically secure.

In fact when you purchase a 'wall plug' you'll see that its metal mounting ears and screws are spaced and designed to connect to an electrical box.

Watch out: while it's physically possible to install a wall receptacle or 'plug' without using an enclosure, doing so is dangerous, risking fire and shock, and of course, it's also illegal in virtually every building code jurisdiction.

Take a look at our photograph at left - a fire was contained within this electrical junction box. Had the box been omitted there is a good chance the fire would have spread to the building itself.

When we hear a question like this it makes me very afraid for you and for future building occupants - as amateur electrical wiring is dangerous.

Details about how to wire up an electrical receptacle are

at ELECTRICAL RECEPTACLE CONNECTION DETAILS - where to connect black, white, red, green, ground wire.

Gang Boxes - built-up electrical boxes for more space

Gang boxes are steel electrical boxes with removable sides and screw fittings that permit multiple metal boxes to be joined together to obtain more space. As we discuss

at ALUMINUM WIRE REPAIR SPLICE SPACE,

Some electrical boxes installed as original work are stamped out of a single piece of steel and cannot be expanded. Others called 'gangable' metallic boxes such as by (Thomas & Betts - Steel City Brand) installed as original work included side plates that could be removed to install a sidecar extension.

Gangable electrical boxes can be expanded by adding another box along the open (away from the stud or joist) side of the existing box (requiring a larger wall opening), or by adding a 'side car' extension that hides behind the wall surface.

Sketch at left: illustrates the removable side-plates on a gang-type electrical box.

Boxes of this type can be expanded along their open side - the side that has not been already fastened to a stud or joist.

To add an electrical box extension you must have access to the top or bottom screw on the open side of the box to remove the side plate - that's where you'd add on a second gangable box as an extension or a side-car hidden box extension.

Watch out: it will be almost impossible to extend an original-work metallic box size using an extension without cutting open and thus damaging the wall at one side of the box.

However in my OPINION drywall repairs are trivial compared with the cost of complete re-wiring with all copper in a building with aluminum wired branch circuits.

Gang Box Extenders for More Wiring Space

In addition to screwing multiple gang boxes together to construct a large 'new work' electrical installation, gang boxes can be extended behind the wall to obtain a small amount of additional wiring space: illustrated below.

At above left is a single 'gang box' steel electrical box.

Below I've removed the left side of the gang box and I have installed a steel'side car' or 'box extender' (yellow arrow in the photo below) to increase the cubic inches of wiring space in this electrical box.

These box extenders can be used to add a small amount of wiring space that can bring an otherwise too-small gang box up to code without having to cut a larger opening in the building wall.

You'll notice that the box extender is shaped to be recessed to slip behind the thickness of the plaster or drywall.

Below we see a modern GFCI electrical receptacle shoehorned into a too-small gang-box that has been extended with a box extender or 'sidecar' in order to try to include AlumiConn™ aluminum-to-copper pigtailing connectors.

See ALUMINUM WIRE REPAIR SPLICE SPACE where we discuss all of the approaches to obtaining more wiring or device space in electrical boxes.

Where wall depth permits, a better approach where more wiring space is needed is to remove the existing electrical box and install a deeper box in the same opening.

Electrical box extensions & supplies for more wiring space or increased cubic inches of electrical box space

Thomas & Betts (ABB Group) Steel City electrical boxes, Thomas & Betts Corporation 8155 T&B Boulevard Memphis, TN 38125 Phone: 901-252-5000, Phone: 800-816-7809 Fax: 800-816-7810 Email: elec_custserv@tnb.com Website: http://www.tnb.com/
Home Depot stores
Loews Building Supply stores
Local electrical contracting suppliers in your area
U.S. Patent No. 5,117,996, June 2, 1992 describes an electrical box extension submitted by William J. McShane, Philadelphia, PA. McShane patented a number of electrical box extension designs to accommodate wall thickness changes as well as space additions.
Danbury toP&M Electric supply (29 Federal Road, Danbury CT 06810, Tel: 203-744-7445), The RAC535 X-cube adapter .5cui steel sidecar electrical box space extender retails for $1.79 and a RAC519 2 12/D NMC gang-type electrical switch steel box retails for $2.45.

New Work Compared with Old Work Electrical Boxes - Old Workboxes

New Work Electrical Box Examples

Normally a 'new work' plastic electrical box installed during new construction is either nailed to the building framing (shown below) or if it needs to be spaced away from a stud or joist in a wall or ceiling it may be supported by a bracket that is in turn nailed to the building framing.

See ELECTRICAL JUNCTION BOX TYPES.

Examples of Old Work Electrical Boxes & Methods of Installation

When an electrical circuit and electrical boxes are being added to an existing structure wires are snaked through building cavities to the desired fixture location and an old-work electrical box or 'junction box' is installed to contain electrical splices and devices.

Both metal and plastic old-work electrical boxes are available and there is a variety of clips, clamps, and other devices used to secure electrical boxes in a wall or ceiling when the box cannot be conveniently nailed or screwed directly to the structure.

[Click to enlarge any image]

At above is a steel gang box with mounting hardware to permit old-work installation: those metal brackets at the top and bottom of the box can be screwed to a wall surface.

In my opinion I'd prefer to see this box used in a wood or paneled wall or on a plaster wall on wood lath rather than on simple drywall as I worry that in a receptacle installation someone may find they pull the whole installation off of the drywall when removing a wall plug.

Above we illustrate thin steel clips (colored orange) that have been used (with considerable care) to secure a steel gang box in a drywall or plaster wall (adapted from Steel City products).

See details at OLD WORK ELECTRICAL BOXES for RETROFIT

Reader Q&A - also see the FAQs series linked-to below

On 2020-10-06 - by (mod) -

Yes, Bob,
ALL electrical wiring splices for lighting and receptacles in a building, including the bath, need to be in a metal or plastic electrical box.
It's not technically difficult to add a box - use an 'old work' box - those are sold with various mounting methods that make it easy.
Watch out: IMO if your light is within touching distance of the sink it should be GFCI protected as well.
See OLD WORK ELECTRICAL BOXES for RETROFIT

On 2020-10-06 by Bob

I will be installing a new wall mount light fixture in a powder room (toilet and sink only). The current light is also wall mounted. Wiring for the current light comes through a hole in the drywall behind the light and the splice between the wire and light rests on the metal backplate of the light fixture. There is no junction box in the wall behind the light. Will I need to install a junction box and make the splice between the wire and light within the junction box? Thanks.

On 2020-07-12 - by (mod) -

how to install a cluster of electrical receptacles in one location

Mike
You are certainly allowed to install a cluster of electrical receptacles, and I've done that many times myself. However in my opinion you'll be sorry if you put them all on one 15 amp circuit. It seems likely that you will overload the circuit.
At the very least I would prefer to run two or more 20 A circuits to that location and connect the receptacles accordingly so that you don't simply overload the circuit.
Also the electrical box(es) or gang box needs to be big enough to permit all of the electrical connections, wires, and devices.

On 2020-07-12 by Mike

I need to install a cluster of 10 receptacles on a center wall to support a home computer lab. The wall section is actually 4 foot x 2 foot with a gas fire place on of the 4 foot faces. I will be using the other side. I also want to run a dedicate 15 amp circuit. Any code issues with that? Luckily, the breaker box is only about 10 feet away.
The receptacle layout would look like this:
[] [] [] [] []
[] [] [] [] []

On 2020-06-25 - by (mod) -

Jodie
Thank you for a helpful question on electrical box size for two light switches.
A typical 4-inch box is the right size, but the actual box dimensions, in particular, box depth and thus the space needed in cubic inches varies depending on how many wires or connectors will be in the box. Take a look at the tables above on this page for details and you'll see that more connectors means more cubic inches means a deeper box.

On 2020-06-25 by Jodie Naker

Hello - how large of a receptacle box is needed for two light switches / one a single toggle and the other a duplex/ double toggle - use one larger box or two smaller?

On 2020-01-07 - by (mod) -

Pp
Thank you for your interest, but to protect reader trust that our articles are written without bias or conflict of interest we don't sell any product or service and therefore we have no dealer in India nor anywhere else.

On 2020-01-07 by Pp enterprises

Please provide dealer number in india

On 2019-10-23 - by (mod) -

Glen
I'm not sure how you're using the word opening or where the concern lies in the question. Obviously the front of the box as a single opening into which devices are secured. However electrical box may have multiple openings for wiring connections. The number of those will vary as the box size varies.

On 2019-10-23 by Glen

For new construction/remodeling permit , is one box no matter the size, single, double or multi switch considered one opening

On 2019-04-30 - by (mod) -

Lake
We use electrical boxes of varying sizes or capacity (in cubic inches) because the number of electrical wires, connectors, devices varies as well. More devices require more cubic inches, as per tables of electrical box size given in this article series.
Good luck on your test.

On 2019-04-30 6 by lakelyn

Why are there different sizes of outlet boxes in a commercial construction

On 2018-08-31 - by (mod) -

The answer to your perfectly good question depends on the cubic inches that the Box provides matched against the table of cubic inches required for the number of wires and connectors by wire size in the circuit that you are wiring

On 2018-08-31 by Mike

Can I use an old-work plastic box for a 50 amp outlet?

Reader Question: When adding an electrical outlet in a garage, what's code: metal or plastic junction box?

I am putting outlet in garage wall that has kitchen on the other side. What is code, plastic or metal? I would think in a garage fire that a plastic box would melt and fire would go through the wall faster? - Steve Smith

Reply:

Steve both plastic and metal receptacle boxes are code-approved and neither, properly installed and wired, should violate the fire-rating of the wall.

Reader 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

Anne,

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.

Reader Comments:

Anne,
I'm in the midst of a remodel that posed the same 'problem'. Work box extender rings are available at Home Depot and Lowes in the electrical department.

They are plastic, color-coded frames that fit between the front edge of the box and the outlet/switch. The screws that secure the outlet/switch to the box also secure the frame in place.

The frames are available in multiple thicknesses. I suggest you take a tile sample with you so that you can get the correct thickness for your project. Depending on the thickness of the tile, you may need to combine two frames of different thicknesses.

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: how many electrical receptacles are allowed on a 20-amp circuit? How many receptacles on a 15-amp circuit?

How many receptacles can be wired To one 20 amp circuit No. 12. Wire - John K.

Reply: 10 electrical receptacles to be wired on a 15-Amp (#14 copper) wire circuit

John K:

Our photo (left) shows a 20-Amp electrical receptacle - you can recognize it by that horizontal opening that makes the left-hand slot look like the letter 'T' on its side.
In general, the Electrical Code [NEC] allows

10 electrical receptacles to be wired on a 15-Amp (#14 copper) wire circuit, and the Electrical Code [NEC] allows
13 receptacles on a 20-amp (#12 copper) wire circuit.
Watch out: When purchasing the receptacles to use on a 20A circuit, be sure to also buy receptacles that are themselves rated for 20Amp use.
You'll see that those least-costly receptacles found in a big pile at building supply stores are more likely intended only for 15-Amp use.

Our photo (left) illustrates an electrical receptacle intended for use on a 20-Amp circuit.
Notice that extra horizontal slot? You won't see that on a 15-Amp electrical receptacle.

Reader 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

Reply: minimum heights for electrical receptacles is not specified in the electrical code NEC

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.

See ELECTRICAL RECEPTACLE HEIGHT & CLEARANCES for details.

Question: are electrical junction boxes required for wall plugs?

Do I really need an electrical box to put a new wall plug in ? - Thomas

Reply:

In fact when you purchase a 'wall plug' you'll see that its metal mounting ears and screws are spaced and designed to connect to an electrical box.

Take a look at our photograph at left - a fire was contained within this electrical junction box.

Had the box been omitted there is a good chance the fire would have spread to the building itself.

When we hear a question like this it makes me very afraid for you and for future building occupants - as amateur electrical wiring is dangerous.

Question: Which end of electrical outlets go 'up'? The ground hole should be up, down, or sideways?

Can the outlet be installed any way? For example ground hole facing up, down, or sideways? thanks, - Anon

Reply:

Anon, the position of installation of an electrical outlet won't affect its operation and should not normally affect its approval by the electrical inspector.

In some areas I see the outlet installed with the ground connector always 'up' as in our photo at left, though to me that's less attractive than the position shown in our electrical outlet photo at far left.

I've also seen arguments expressing the OPINION that the position of the grounding pin connector might help resist the tendency of a plug to fall out of its connection.

That's nonsense. If a plug is falling out of a receptacle, one of the two objects is worn or damaged and should be replaced to assure a safe, mechanically secure connection.

Question: When adding an electrical outlet in a garage, what's code: metal or plastic junction box?

Reply:

Steve both plastic and metal receptacle boxes are code-approved and neither, properly installed and wired, should violate the fire-rating of the wall.

Question: can I connect a pigtail from multiple hot, neutral, or ground wires over to a receptacle

I have 2 receptacles that are both side and back wired, 3 hot and 3 neutral wires. I eliminated one receptacle (capping the 3 wires together) but want to keep the other. Is it safe to just run a pigtail from the 3 wires to the receptacle? - Greg

When wiring multiple boxes in series, how do you connect both incoming and outgoing ground wires to the back of the receptacle?

With 12 ga. wire, only one wire will fit under the green screw (and not very tightly, at that - there's no washer or clamp.) - Bob M.

Reply:

Yes, Greg, that's a common practice. Be sure that your junction box is big enough to contain all of the wires and twist-on connectors.

Bob, similar to Greg's question, I see two approaches to hooking up the ground wire in junction boxes and at electrical receptacles.

If the incoming ground wire from the feed circuit was left long enough, it can be run continuously, connected to a grounding screw that connects the wire to the metal junction box (skip this step if plastic junction boxes are in use),
on to the ground screw terminal at each electrical receptacle, and ending with a ground clamp crimp connector that ties the incoming ground to the ground wire of the outgoing wire that continues to the next junction box.
If the incoming ground wire is not long enough to run as above, then an additional length of ground wire is pigtailed to the incoming ground and makes the other connections I've described above.

In sum, all of the grounds are tied together in the box: the incoming ground, outgoing ground, and ground wires to each of the electrical receptacles.

Watch out: while the electrical receptacle ground may also be electrically connected to the metal strap that mounts the receptacle to the junction box (photo at left), and while the junction box may be metal, do not rely on the receptacle mounting screws and receptacle strap-to-box contact to serve as the grounding connection.

It's easy for the receptacle mounting screws to be deliberately left loose or to work loose - making that ground connection unreliable.

Use a ground wire.

Question: how many electrical receptacles are allowed on a 20-amp circuit? How many receptacles on a 15-amp circuit?

How many receptacles can be wired To one 20 amp circuit No. 12. Wire - John K.

Reply:

John K:

10 electrical receptacles to be wired on a 15-Amp (#14 copper) wire circuit, and the Electrical Code [NEC] allows
13 receptacles on a 20-amp (#12 copper) wire circuit.
Watch out: When purchasing the receptacles to use on a 20A circuit, be sure to also buy receptacles that are themselves rated for 20Amp use.
You'll see that those least-costly receptacles found in a big pile at building supply stores are more likely intended only for 15-Amp use.

Our photo (left) illustrates an electrical receptacle intended for use on a 20-Amp circuit.
Notice that extra horizontal slot? You won't see that on a 15-Amp electrical receptacle.

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?

Also, what does it mean when an electrical switch with multiple switches which control recessed lights, the ceiling fan and light on the ceiling fan gets hot; what is happening? Is this a fire hazard? - Mrs. Spencer

Reply:

Mrs. Spencer:
It sounds as if you need a licensed electrician to check and secure your loose electrical outlets - I agree that a loose electrical receptacle is unsafe. But an inspection is needed to understand the underlying problem

. It could be simply tightening screws, or it could be that the electrical box itself is not adequately secured in the wall. Luckily there are retrofit parts that can be used and inserted along the box to make it secure, usually without disturbing the surrounding ceramic tile.
Some dimmer switches use a resistor to dim the light and it is common for them to get warm. Very hot - a subjective judgment for homeowners - may indeed be a fire hazard and should be investigated.

Question: how do I increase the projection of outlets into a room so I can add a kitchen backsplash

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

Anne,

Ontario Electrical Code Junction Box Attic

Electrical box extensions are sold in plastic and steel and in thicknesses from about 1/8' up to an inch or even more.

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.

Reader Comments:

Anne,
I'm in the midst of a remodel that posed the same 'problem'. Work box extender rings are available at Home Depot and Lowes in the electrical department. They are plastic, color-coded frames that fit between the front edge of the box and the outlet/switch.

Ontario Electrical Code Junction Box Attic

The screws that secure the outlet/switch to the box also secure the frame in place.

Question: electrical outlet height requirements

I was looking at some height requirements on electrical outlets this is a very informational site.
thanks Jerm 4/19/12

Reply:

Jerm, in the article above at ELECTRICAL RECEPTACLE HEIGHT & CLEARANCES we give the data you want. Let me know if anything is unclear.

Question:

I have one line with power coming into a box that will have one two way switch, one three way switch and one power line exiting. Is it proper to splice the incoming black wire to make 3 black wires by pig tailing with wire connectors and doing the same for the white wire and ground? - is it ok? 12/13/12

Reply:

I'm sorry but I'm confused by the question. I think it's safe to say that in general it's common practice to use a twist-on connector to splice pigtails or individual wires at an individual hot or neutral wire where more connections are needed than fit with the original wire.

Just watch out to avoid violating the space or number of connectors permitted in a junction box of the particular size you're working on.

...

Continue reading at ELECTRICAL RECEPTACLE LOCATIONS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see ELECTRICAL BOX TYPE FAQs - questions & answers posted originally at this article

Or see these

Electrical Box Articles

ELECTRICAL BOX TYPES
SIZE of WIRE REQUIRED for ELECTRICAL RECEPTACLES for receptacle circuits and similar wiring situations

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ELECTRICAL JUNCTION BOX TYPES at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to ELECTRICAL INSPECTION & TESTING

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Technical Reviewers & References

Timothy Hemm has provided photographs of various electrical defects used at the InspectAPedia ^TM Website. Mr. Hemm is a professional electrical inspector in Yucala, CA.
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Mr. Cramer serves on the ASHI Home Inspection Standards. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com
John Cranor [Website: /www.house-whisperer.com ] is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. He is also a contributor to InspectApedia.com in several technical areas such as plumbing and appliances (dryer vents). Contact Mr. Cranor at 804-873-8534 or by Email: johncranor@verizon.net
[3] NFPA - the National Fire Protection Association can be found online at www.nfpa.org
[4] The 2008 NEC National Electrical Code (ISBN 978-0877657903) Online Access LINK (you'll need to sign in as a professional or as a visitor)
[5] Special thanks to our reader Steve who pointed out prior errors in our illustrations.
[6] Simpson Strong-Tie, 'Code Compliant Repair and Protection Guide for the Installation of Utilities in Wood Frame Construction', web search 5/21/12, original source strongtie.com/ftp/fliers/F-REPRPROTECT09.pdf, [copy on file as /Structures/Framing/Simpson_Framing_Protectors.pdf ]. 'The information in this guide is a summary of requirementsfrom the 2003, 2006 and 2009 International Residential Code(IRC), International Building Code (IBC), International PlumbingCode (IPC), International Mechanical Code (IMC), 2006 UniformPlumbing Code (UPC) and the 2005 National Electrical Code.'
'Electrical System Inspection Basics,' Richard C. Wolcott, ASHI 8th Annual Education Conference, Boston 1985.
'Simplified Electrical Wiring,' Sears, Roebuck and Co., 15705 (F5428) Rev. 4-77 1977 [Lots of sketches of older-type service panels.]
'How to plan and install electric wiring for homes, farms, garages, shops,' Montgomery Ward Co., 83-850.
'Simplified Electrical Wiring,' Sears, Roebuck and Co., 15705 (F5428) Rev. 4-77 1977 [Lots of sketches of older-type service panels.]
'Home Wiring Inspection,' Roswell W. Ard, Rodale's New Shelter, July/August, 1985 p. 35-40.
'Evaluating Wiring in Older Minnesota Homes,' Agricultural Extension Service, University of Minnesota, St. Paul, Minnesota 55108.
'Electrical Systems,' A Training Manual for Home Inspectors, Alfred L. Alk, American Society of Home Inspectors (ASHI), 1987, available from ASHI. [DF NOTE: I do NOT recommend this obsolete publication, though it was cited in the original Journal article as it contains unsafe inaccuracies]
'Basic Housing Inspection,' US DHEW, S352.75 U48, p.144, out of print, but is available in most state libraries.

Are Electrical Junction Boxes Allowed In Attic

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3 Answers. There is no problem with installing junction boxes above a suspended ceiling, as long as the box is less than 100 in. ³ and securely fastened.

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Accordingly, can you put a junction box in the ceiling?

Junction boxes must be installed where they are always accessible; never install a junction box in a concealed wall or ceiling space where the box cannot be accessed in the future. Junction boxes also must be covered with solid covers with no holes.

Beside above, is it OK to use junction boxes? Never connect wires outside of electrical boxes. Junction boxes (or a J box) protect the connections from accidental damage and contain sparks and heat from a loose connection or short circuit. Where connections aren't contained in an electrical box, install a box and reconnect the wires inside it.

Ontario Electrical Code Junction Box Attic Fans

Also know, can you drywall over a junction box?

Junction box covers must remain accessible; they cannot be covered with drywall or other surface material.

Ontario Electrical Code Junction Box Attic Ladder

Are junction boxes bad?

Ontario Electrical Code Junction Box Attic 2

Overfilling a Junction BoxCramming too many wires into a junction box is not only dangerous, but it's against the National Electrical Code. Plastic junction boxes are stamped with their approved volume; you may have to calculate the volume of a steel box on your own.