How to Shield a Wire From Interference

By Techwalla Electronics Editor

It can be hard enough to wire a telephone, electrical or audio line without having to worry about interference. However, modern homes have so many different electrical appliances that shielding is almost always necessary. Here are a few easy ways to shield your wire from interference.

Things You'll Need

  • Shielded wire
  • Shielded extension or power cords
  • Work gloves
  • Shielded conduit
  • Shielding foil

Step 1

Use shielded conduit when you're wiring your home to reduce interference. These conduits are more expensive than the non-shielded variety and you should use them only when you must place different kinds near each other. Be sure that you buy flexible conduit if you must use it in corners.

Step 2

Wrap magnetic shielding foil around your wiring to protect it from interference. This material is cheaper than buying shielded conduit, but takes time to wrap around your wiring.

Step 3

Evaluate the cost of wiring your home with shielded wire. Shielded telephone and electrical wires can be purchased from most hardware stores and can significantly reduce interference. However, these wires are more expensive than wire that does not shield against interference.

Step 4

Purchase shielded power cords for home appliances. Some clocks, lights and televisions generate electrical fields even when they're turned off. Using these power cords can reduce interference. However, they are expensive, so you might use them only on appliances that are creating noticeable interference.

Step 5

Keep a distance between different kinds of wires. Electricians recommend that you place telephone, audio and electrical wires no closer than 1 foot from each other. If the wires must be near each other, don't put them in the same conduit.

Step 6

Check the connections to your appliances periodically to be sure that frayed wires aren't causing interference. Some speaker wires fray at the ends, which can cause sounds similar to interference. This problem can be corrected by replacing the wires.

Tips & Warnings

  • When you try to find out which device is causing inference, unplug each device. It isn't enough to just turn it off.
  • If you have an older home, talk to an electrician about converting two-prong outlets into three-prong outlets. The third, round prong on an outlet is the ground connection, which can often reduce interference.
  • Shielding foil can be sharp and can easily cut your hands if you don't wear work gloves while handling it.
  • Do not use glue or another adhesive to secure shielding foil to your wires unless the foil explicitly requires it.