Electrical Box Knockout Sizes

These boxes protect wiring from the elements with gaskets sealed seams and watertight covers.

Electrical box knockout sizes.

Standard household circuits are either 15 amp or 20 amp and have 14 gauge 14 awg and 12 gauge 12 awg conductors respectively. Hydraulic with piece maker. Here are the maximum box fill limits for a few common sizes of electrical boxes. 12 awg is larger than 14 awg so a box can have fewer 12 awg conductors than 14 awg.

I know that i will need to drill with hole saws or use a knockout punch in junction boxes and the circuit breaker panel. Knockout non metallic push in connector. But sometimes the standard knockout openings in a wall box aren t large enough for the cable clamp or conduit fitting you need to attach to the box so you have to enlarge the hole. Electrical trade sizes and plumbing trade sizes are equal and are based on pipe sizes.

I plan to install a lot of electrical conduit. 1 2 to 1 1 4 158pm. 1 2 to 2 179pm. Electrical boxes conduit fittings.

Knockout type conduit size hole range part number page no. A standard rectangular shape is the most common electrical box. 1 2 to 2 152. It houses a single electrical switch or outlet and comes in metal or nonmetallic units.

First determine the size of the missing knockout hole and subtract 3 8 to figure out what size knockout plug you ll need. I have posted the hole saw and knockout sizes for electrical conduit below. Different electrical box sizes fit varying installation needs. 1 2 to 2 170pm.

For example if you have a 7 8 hole you ll need a 1 2 knockout plug. 1 1 2 to 2 159pm. 1 2 to 4 154. Trade size in 1 1 2 57 1 1 4 62 1 2 152 1 93 2 1.

Notes to the table above. An example is 1 2 inch 1 3 cm trade size. Knockout holes or knockouts in electrical boxes are made at the factory and have standard sizing to match cable clamps. To determine the actual opening for this size you need to add 3 8ths of an inch which is 7 8ths of an inch opening.

What are the actual hole saw sizes for the various trade sizes of electrical conduit. The 3 4 inch 1 9 cm trade size is a 1 1 8 inch 2 9 cm opening.