Electrical wiring repairs are crucial for any home or business. However, knowing when you need to invest in electrical repairs is not always an easy task. Recognizing the first signs of trouble is crucial for preventing complicated hazards that can cost both your health and money. Knowing how to identify, buy and install different kinds of electrical wiring is essential. This comprehensive guide will provide you with everything you need to know about your home’s electrical wiring.
What You Should Know About Electrical Wire Sizing
The first thing you’ll notice when you step into an electrical shop is that there are many different types and sizes of electrical wires. The choice of electrical wire depends on the usage. That’s why knowing the right wire gauge, size and type is vital to the functioning of your electrical system.
Electrical wires are sized according to the American Wire Gauge System (AWG). The gauge is related to the physical size of the wire. The smaller the wire gauge, the larger the diameter of the wire. Basically, the size indicates how much current can the wire handle safely. Every wire gauge size comes with a maximal limit for carrying electrical current safely.
Knowing these different capacities allows you to determine which wire size you need. Below you will find the different amperage capacities for standard non-metallic (NM) cable:
| Wire Gauge Size | Amp Capacity |
| 16 | 13 |
| 14 | 15 |
| 12 | 20 |
| 10 | 30 |
| 8 | 40 |
| 6 | 55 |
| 4 | 70 |
| 3 | 85 |
| 2 | 95 |
Keep in mind that amperage capacities may vary. For example, aluminum wiring has different amp capacities. It used to be a very popular choice for electricians and homeowners alike.
However, the problem with aluminum wires is that they would sometimes loosen up due to aluminum’s greater expansion profile under load. This would lead to accidental electrical fires. Surely, if your home has an aluminum electrical wiring system, that doesn’t mean that you are automatically at risk. However, regular inspections are recommended to know whether electrical wiring replacement is needed.
What You Should Know About Electrical Wiring Sheathing
Most of the interior wiring of homes is done using NM cable, often referred to by the popular brand name Romex. Non-metallic cables are made of three or more wires that are wrapped inside what is called the sheathing, which is basically a flexible plastic wrap. NM wiring is by far the most common and popular choice used for light fixture installations, outlets, switches, different appliances and more.
To identify the gauge size of the wires within the sheathing you have to look at its color. Here is a quick overview of the most common sheathing colors and their respective wire gauges:
| Sheathing Color | Wire Gauge | Intended Amp Service |
| White | 14 | 15 |
| Yellow | 12 | 20 |
| Orange | 10 | 30 |
| Black | Heavier gauge wires | 40 – 60 |
Top 4 Electrical Wiring Safety Principles You Should Know About
Dealing with electrical work requires the right knowledge and careful precautions. Making contact with a hazardous electrical part puts your life at risk. Therefore, understanding basic electrical safety principles is vital, not only for homeowners who want to attempt DIY electrical work, but for professional electricians as well. Below you will find a summary of the four most important principles:
Only work on dead equipment
Trying to work on live electrical equipment is extremely dangerous! The majority of electrical repairs or installations must be performed on dead equipment to avoid potential hazards. That’s why you should never attempt to interfere with a live electrical appliance!
Even professional electricians are instructed to carefully shut down any equipment before proceeding with their work. Not only can this practice save lives, but it can also save you money and time in the long run.
Lock it out
In some unfortunate cases, equipment may accidentally be reenergized. This happens due to lack of proper control. That’s why you should make sure to always lock out the device. Lockout or Lockout/Tagout is a process that refers to one of the most fundamental electrical safety practices. It involves padlocking the isolation switch or breaker to ensure that the electrical equipment is properly isolated throughout the whole duration of work.
Test the device
Hazardous voltage is impossible to detect without the proper equipment. Do not ever think that you can make sure a device is dead simply because the noise went away or the lights went off. Most people think that the circuit is dead, however, find themselves getting shocked after touching the device. The proper way to test a device for voltage is by using a contact multimeter or another type of voltage tester.
Remember: you should first verify if the meter is in proper working conditions by using it on a known live circuit before and after the zero voltage measurement.
Be qualified for the job or call an electrician
To guarantee that electrical work is being carried out safely, you should ensure that the person doing the work is fully qualified for the job. If you’re going for a DIY project, ask yourself these questions:
- Can you recognize the hazards?
- Do you know which parts could be live? If yes, to what voltage?
- Are you competent enough to work on the system?
- Can you read and follow a circuit diagram?
- Do you know how to choose the right tools?
- Do you have the necessary personal protective equipment?
- Do you have relevant hands-on experience?
- Do you know the body positioning techniques that will help keep you safe?
DIY work can be quite complicated. There are many risks involved with electrical procedures and recognizing when things are wrong is often not enough. That’s why we always recommend that you trust a professional electrician. Electricians have the right licensing and technical expertise that allow them to perform electrical repairs and installations safely.
Moreover, they are equipped with the necessary tools for the job. Calling an electrician instead of attempting to work on your electrical system yourself can save you not only time and money, but also your health.
Understanding Electrical Wiring Color Coding
Electrical wiring colors help us identify which wires carry an electrical current and which ones are used for ground or neutral purposes. Understanding these colors is very important when it comes to dealing with electrical work.
First of all, you should know the difference between sheathing colors and wire colors. The color of the sheathing refers to the gauge of the wires inside. The color of the wire inside refers to the wire’s intended use and its potential danger. Here is a quick overview of electrical wiring colors and their meanings:
| Sheathing Color | ||
| White | 14-gauge wire | Light circuits |
| Yellow | 12-gauge wire | GFCI outlet circuits |
| Orane | 10-gauge wire | Larger devices: dryers, water heaters, AC, etc. |
| Black | Heavier wires | Devices that require 40 amps to 60 amps |
| Wire Color | |
| Black & Red | Current-carrying or hot connections |
| White | Grounded neutral conductors |
| White Wires with Black or Red Tape | Hot wire (rather than a neutral wire) |
| Green & Bare Copper | Grounding Wires |
Understanding Electrical Wiring Labels
If you were to look closely at any electrical wire, you would notice that they have markings stamped or printed on them. These labels provide valuable information related to the wiring and its insulation. Apart from the wire color, these labels will help you determine which type of wire is the best to ensure that your electrical system is working properly.
Below you will find an overview of the typical non-metallic cable labels and their meanings:
| Label | Meaning |
| 14-2G | 2 insulated 14-gauge wires + 1 ground wire |
| 14-3G | 3 insulated 14-gauge wires + 1 ground wire |
| 12-2G | 2 insulated 12-gauge wires + 1 ground wire |
| 12-3G | 3 insulated 12-gauge wires + 1 ground wire |
| 600 V | Cable rated for max 600 volts |
| Type NM-B | More resistant than NM cable. Standard for residential installations. |
What Kind Of Electrical Wire Should Be Used Outdoor?
Standard electrical wires are meant to be used in indoor settings, where walls, ceilings or floors provide sufficient protection from humidity. If you are going to work on outdoor structures or underground, you have to use direct-burial cable. Direct-burial cables can withstand moisture and direct exposure to soil.
Basically, this kind of wire is specifically designed for wet and damp environments. Never attempt to install standard electrical wires outside, as that could lead to extreme hazardous situations!
What Is Electrical Wire Stripping?
Electrical wire stripping refers to the process of removing the sheathing or plastic insulation that surrounds the wire’s metal core. Stripping electrical wires must be done very carefully! If you don’t know the proper technique or have the right tool for the job you risk damaging the wire.
Although stripping electrical wires is not overly complicated, we recommend that you contact a professional electrician if you are dealing with a large project.
Electrical Wiring In A Circuit Breaker Panel
The electrical panel serves as the main power distribution point of your home’s electrical system. In other words, all the individual electrical circuits of your house are powered through the electrical panel, which protects them by fuses or breakers. Electrical panel installation should be performed only by a qualified electrician.
Repairing or replacing an electrical panel is quite a complicated task. What you should do is learn how to recognize the signs that your electrical panel needs repairing, so that you can call an electrician in due time. Here are some of the most common signs that your electrical panel is malfunctioning:
- Dimming or flickering lights,
- Tripped breakers and power surges,
- The electrical panel is emitting too much heat or smoke,
- The electrical panel is broken, rusted or making odd noises.
What About Electrical Disconnect Switches?
Electrical disconnect switches are used when you need to immediately shut off the power to your home. Usually, these devices are installed in outdoor locations. Electrical disconnect switches come in handy in many different situations. Whether you need to make sure your home’s electrical system is completely shut down in case of malfunctions, or you need to make new repairs or installation safely, a switch is worth having.