The nec dictates how many wires and clamps you.
Ceiling fixture box installation.
Install a plastic old work ceiling junction box if your fixture weighs 10 pounds or less.
Installing a ceiling electrical junction box.
1 gang box ceiling fan mounting box recessed boxes brackets 3 4 in.
Push the box into the hole in the ceiling until the lip of the box is flush with the drywall.
Before you begin make sure your junction box can support the weight of the new light fixture.
Installing a light fixture or outlet in the ceiling requires an electrical junction box to hold the wire connections and the fixture or device.
The box above is ready for a standard light fixture installation.
Check the label to make sure the box is designed to support more than 35 lbs.
Pull the electrical cable that s hanging from the ceiling through a knockout hole in the back of the box.
A grounding pigtail was added using number 14 wire and a 10 32 green ground screw.
If your fixture weighs more you may need to install a junction box that s designed to support heavier light fixtures.
Most ceiling boxes are large enough.
An easy solution is to install a fan brace box available from home centers and hardware stores that s designed to be installed without cutting any additional holes in your ceiling.
The box is grounded through the correct use of the cable connector and the bx armor.