refaxpress.blogg.se

If the volume is not marked on the plaster ring, domed cover, etc., or it is not made from a box the dimensions of which are listed in Table 314.16(A), the volume cannot be counted. We just use 4 square deep boxes and add an extension ring if we are crowded for space. When this 1 1/4 inch extension ring is mounted on a 4-inch square box that is 2 1/8 inches deep, the maximum number of 10 AWG conductors permitted is 19 (See Figure 5). Most of the time electricians don't go through all this. You then select a box that will has that much volume.Ī raised cover or mud ring (used to mount a device) also adds volume to the box. This is your total cubic inch fill required. 19), top row) or an outlet box with a plaster ring using appropriate No. Multiply that by the cubic inch of the size of wire on Table 314.16(B). determine the number of wires permitted in a given size box. You then add up all the wires that are counted and all the items counted extra like yoke mounted devices and internal cable clamps. Or do you just count only the number of wires? Yoke mounted devices count as a 2 wire allowance for the largest conductor terminated to the device.

Wires that originate in the box and stay in the box, such as pigtails, do not count. All gound wires only count as one no matter how many ground wires you have. Each wire that passes through the box without making a joint counts as only one. Each wire that enters the box and is terminated on a device counts as one. So, if you hae a joint with three wires that counts as 3. Each wire that enters the box and makes a joint is counted as one wire. Read through Article 314 to see how to perform the count.ĭo you count the connectors as one besides the three wires or so that might be connected to it? It's a 120mm x 1.5" box, that's 29 cubic inches, so you get a raised receptacle cover that gives 5 more cubes and you're done.Īs Tester101's answer that he referred you to states, go to Table 314.16(A) and you would see that a 4x4x1 ½ box can hold 10 #14 wires as counted according to the article. Its ground was counted earlier.Ĥ wires #14 (the Romex ground was counted earlier) so 8.00.ġ receptacle, largest wire involved is #14, x2 so 4.00.ġ cable clamp, largest clamped is #14 so 2.00. Then 14/2 Romex going out to some other location, with a clamp, and its ground goes to the steel box case. You also have #14 hot and neutral THHN coming in, going to a receptacle at this box. You have four #6 THHN wires (hot hot neutral ground) passing through the back of the box on their way to a subpanel. Yes I know they are dramatically different sizes. What's a yoke? A switch, receptacle, GFCI etc. Common box sizes have official sizes, and the sales literature for those boxes will also say. There should be a stamping on the box saying how many cubic inches it is.

So if you have a 10AWG wire in there for some reason, that yoke counts as 5.00 c.i. For each yoke, what's the largest wire going onto that yoke? Look it up and count it twice.Any wires over 12" length, look it up, that per extra foot.2 wires nutted together don't count as one, sorry.if you have two 12/2 cables into the box, grounds are already accounted for leaving 4 wires, x 2.25 cubic inches = 9.00. Other than that, every wire passing through entering and terminating in the box in a cap, splice or device, costs what the table says.Any support brackets? Pick the largest wire associated with the supported item, look it up.Any cable clamps? Pick the largest wire clamped, ditto.If you have four #14 grounds and one #8, that's 3.00 cubic inches.

Pick your largest ground wire and look it up and add it once.Start with this table that says how much space for each wire size. To that we add plaster rings single, double, round etc.I use a shorthand version of the full NEC treatment. have to increase your ungrounded conductors from 3/0 cu to 250 kcmil. This may seem like overkill but when putting in the devices it goes much quicker and there is no question of having the required conductor space.ĭo not forget that 300.14 requires 6" free conductor and on a box of this size 3" outside the box, using 6 AWG on the 50 amp outlet makes getting this much conductor in the box a bit tough.ĩ9% of our work is commercial, the only boxes we use are 4" deep and 4 11/16" deep boxes. the plaster ring have to be, minimum, if you have five (5) number twelve two. 5 Pack) for Single Gang Wall Plate, Telephone Wires, Network Cables, HDMI, Coaxial, Speaker Cables, Black. Thinkgood both items you show are good for surface installations.ģ0 amp we use a 4"sq Deep box with a two gang "plaster ring" that makes a 4" sq box have the front dimensions of a two gang box but leaves more volume for conductors in the rear.ĥ0 amp we use a 4 11/16" sq Deep box with a two gang "plaster ring" that makes a 4 11/16" sq box have the front dimensions of a two gang box but leaves even more volume for the larger 50 amp conductors in the rear. 1 Inch Plaster Washers Metal Washers for Screws Plaster Repair Rings Plaster Buttons Profile Washer Flat Washers for Wall Ceiling Drywall Plaster Repair (200) 4.7 out of.