Page 520 - 2018 National Home Improvement

2018 National Home Improvement Estimator, All Rights Reserved Page 414

Low Voltage Wiring
Phone lines, coax TV cable, computer network cable and speaker wire don’t present the same degree
of risk that comes with 120-volt alternating current circuits. Because of this, the NEC has only a few
simple rules for low voltage wiring. Primary among these is keeping low voltage wiring out of conduit,
junction and outlet boxes that include 120-volt wiring. Low voltage wiring is dangerous if it’s
interconnected with regular AC circuits. You should also keep video, speaker and data cable at least a
foot away from AC cable. That will minimize the effect of radio frequency interference (RFI) generated by
alternating current circuits.

But don’t let these rules impede progress. While adding or extending AC circuits, use the opportunity to
also add new connections for modern low voltage conveniences. Most of the houses you’ll be upgrading
were built long before the need for phone jacks in every room, multiple cable TV outlets, and computer
network cabling.

Adding Outlets and Switches
Most rooms in old houses have a single electrical outlet, and all the outlets in the house may be on the
same 15-amp circuit. That’s enough power for a few lamps and not much more. It certainly won’t
support a modern lifestyle. You may be able to turn on the lights and watch TV in the evening, but forget
the microwave popcorn!

The NEC sets standards for residential electrical outlets. These standards may or may not be enforced
in home improvement projects in your community. The degree that these regulations affect your project
may be a matter for negotiation between the contractor and the building department. Select an electrical
contractor with experience in negotiating with building inspectors. Remember, however, that the code
exists for a reason and most of what it requires is simply good professional practice. Follow the code
standards whenever possible.

Spacing of Outlets – In most rooms, the code requires that no point along the floor line be more than 6'
from a receptacle. That means you need an outlet at least every 12' along walls. Floor outlets don’t help
meet this requirement unless they’re near the wall. Different standards apply to kitchens, bathrooms
and laundry rooms. Spacing in hallways can be 20' and closets don’t need any outlets at all.

Kitchens – Plan at least two 20-amp small appliance circuits to serve the kitchen, pantry and dining
area. These circuits are in addition to circuits used by the refrigerator, dishwasher, oven, range, garbage
disposer and lighting. Every kitchen counter wider than 12" needs at least one outlet. No point on a
kitchen counter can be more than 24" from an outlet. That means you need at outlet at least every 4'
over counters. Outlets have to be mounted on a wall, not face-up in the counter. The outlet next to the
sink must be protected with a ground-fault circuit interrupter (GFCI). Plan on dedicated circuits for the
range, dishwasher, garbage disposer, refrigerator, and microwave oven. A microwave oven will trip the
breaker if it’s on the same circuit with another large appliance, such as a refrigerator.