Electrical Cables Through Wood Framing

 How to Install Electrical Cables Through Holes When You have a Limited to a Maximum Number of Cables

How to Install Electrical Cables Through Holes

Electrical Question: Dave, I set and finish the wiring of Modular homes.

• To connect the wiring in the several sections of the house together I must drill through 4- 2 x 10 band joists and feed a large number of separate circuits through the hole.
• There may be as many as 10 to 12 separate Romex cables to feed from one side to the other.
• I previously drilled one or several large holes and pulled as many cables as I could through the hole.
• I have been told that I am now limited to a maximum number of cables that I can put through such a hole. Is this correct and what is that number?

Thanks,
Jack

Background: Jack, a Contractor from Butler, PA. USA

Thanks for your electrical question Jack.

How to Install Electrical Cables Through Holes When You have a Limited to a Maximum Number of Cables

Electrical Code for Installing Electrical Cables

• NEC 334.80 States that where more than two NM cables containing two or more current-carrying conductors are bundled together and pass through wood framing that is to be fire- or draft-stopped using thermal insulation or sealing foam, the allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a). This only requires derating if the hole is to be fire stopped or filled with sealing foam.
• There is no limit as to the size of the hole or the number of cables that may pass through where draft-stop or insulation sealing foam is not used.

RESOURCES

Electrical Wire for the Home

Electrical Circuit Wiring

This article looks at common 120 volt and 240 volt house wiring circuits and the circuit breakers that are installed identifying the types and amperage sizes used in most homes.
Electrical Panel Circuit Listing

Electric Circuit Listing

The size of the home electrical service panel is designed by calculating the square footage of the home and factoring in the code requirements for the electrical circuits that are required.

Electrical Code Articles for Home Wiring

Electrical Code Directory covering methods for installing electrical-wiring.

Electrical Wiring Tools

A listing of the electrical tools and drills I use on most all of my electrical jobs and projects.

 Learn How to Wire it Right with my Complete Guide to Home Electrical Wiring Perfect for Homeowners, Students, Handyman, Handywomen, and Electricians Includes: Wiring GFCI Outlets Wiring Home Electrical Circuits 120 Volt and 240 Volt Outlet Circuits Wiring 3-Wire and 4-Wire Electric Range Wiring 3-Wire and 4-Wire Dryer Cord and Dryer Outlet How to Troubleshoot and Repair Electrical Wiring Wiring Methods for Upgrading Electrical Wiring Electrical Codes for Home Electrical Wiring ....and much more. » Click here to learn more about Home Electrical Wiring «