Home Improvement Tips: Wiring Switches

Simple projects like replacing switches can be done by homeowners, with caution

Working with electricity can be hazardous, but some minor projects can be accomplished by the DIYer; however keep in mind the rule of thumb: when in doubt, call a professional

DENVER, CO – Many people — and let’s be honest, especially men – fancy themselves handy enough to tackle small repair, replacement and enhancement projects like installing light switches, receptacles and lights. Or in some cases it isn’t the DIYer complex, but rather the aversion to spending the money on a professional electrician that drives people to Do It Yourself.

The truth is that simple electrical projects in and around the home can be done relatively easily by the homeowner, and the easiest among these involve installing or replacing light switches, receptacles (“plugs”) and fixed lights connected to switches.

Like everything else involving electricity, extreme care should be taken at all times. Even for the most minor of projects, it is wise to purchase a simple circuit tester to afford some assurance that the circuit being worked on is indeed off. There are also relatively inexpensive testers available at most hardware stores that can identify the “hot” wires and measure the amperes being used in the circuit.

If you are going to add or replace a light switch in a particular area, the paramount first thing to do is to identify the circuit that is supplying the power to that area so you can switch off the power supply at the circuit breaker. If you are installing a new switch, light or receptacle you’ll have to identify the circuit being used to supply the power and make sure it is turned off at the circuit breaker.

The easiest job, of course, is simply replacing a switch, light or receptacle. You take the old one off and rewire it in the same way. Make sure the switch is placed in the box so that “on” is up and “off” is down. For a switch, the black or “hot” wire from the power source leads directly to the bottom connector on the switch, and the white “neutral wire goes on the top. There are generally two ways to make these connections: most modern switches have both a screw (where the stripped wire is wrapped around and the screw tightened), and there is a hole on the back of the switch where a ½-inch stripped wire can be inserted. Then the wire leading out to the light is attached in the same way (wrapped around the screw or inserted in the hole), from the other side, with the “hot” or black wire leading out from the top connection. If the box is metal, attach the ground wire to the box; if it is plastic take all the other wires and cap them off with an electric screw cap.

If you are pulling wires to connect a new switch the job is much more difficult. Pulling wires through an existing wall is a task better left to a professional. If you are placing such a switch in a new wall or one that will be covered with drywall later, then you’re in luck. Make sure the circuit if off and connect all the wires in the same way. For receptacles (“plugs”) the connections are very similar and should be just as easy.  Switches should be 48 inches off the floor for convenience and it is recommended that they be placed in easy-to-reach spots that won’t be hidden by furniture.

When it comes to wiring light fixtures so they work off the new switch, all these same guidelines apply. You can attach the wires on an existing light switch the same way they came off; for a new one follow the instructions included in the light fixture package.

With all switches, receptacles and light fixtures, turn the circuit back on and test them before securing the boxes or fixture in the wall or ceiling

These are fairly simple tasks. It takes a little more skill to install dimmer switches or such room light with multi-purposes like ceiling fans, but these devices comes with relatively detailed instructions that the handy homeowner should be able to handle.

Where it gets tricky to install such devices is when you are putting a light fixture on two switches, like at opposite ends of a hall, both of which can turn on and off the lights. These are called 3-way switches.

First, bring the power supply in to one of the switch boxes (one hot, and one neutral), on a #14/2-wire cable, then run a #14/3-wire to the other switch location. From the second switch, run a #14/2-wire up to the light box. In the first box, splice the neutral (white) wire from the power supply to the white wire in the 3-wire cable going to the other switch. Attach the hot (black) wire to the common screw on the 3-way switch. The red and the black conductor from the #14/3 cable will be called the “travelers”, and will hook up to the two remaining screws on the switch. At the other switch location, you will hook the white wire from the #14/3 to the white wire going up to the light. The “travelers” (black and red) from the #14/3 will connect to the same screws as on the other 3-way switch, and the black wire going to the light will tie on to the “common” screw.

Of course, if you are installing switches and plugs into kitchens, bathrooms, basements or garages, most local codes require these to be GFI – ground fault interrupter – switches; these are called for anywhere there is water in close proximity. These types of devices are wired similarly to regular devices, and the generally come with instructions that can be easily followed.

The thing to remember about electricity in the home, even on small projects, is that it can be dangerous. There is, of course, the potential of shock, and improper wiring can lead to fire. Some older homes, wired before current codes were in place even just a few short years ago, have wires that would not pass muster in today’s environment, and years-older homes contain wires that were never color-coded. The best rule of thumb is: if in doubt, call a professional.

When you need expert, professional electrical services – from minor repairs and replacements to major projects, emergencies, even remodeling projects – call on Allstar Electrical Services, serving the commercial and residential electric service needs of the Denver are for over a decade. Call 303-399-7420 for complete details.