Many residential service calls involve homeowners adding something new to their homes. This usually requires a larger electrical capacity than what is currently available from the main service panel.
The first thing to look at is how the electricity enters the house. This is called the Electrical Service. It is the responsibility of the customer to furnish and maintain the weather head, mast, meter box, disconnect and grounding.
Switches
Switches allow you to control the current running through a circuit. They work by creating an air gap that has different electrical properties than the conducting material of the circuit. This can disrupt the flow of electricity and prevent it from flowing to where it shouldn’t.
Electric switches have a current rating that indicates the maximum amount of electricity they can carry before starting to incur physical damage. This includes deformation and melting of the components inside. They also need to be resistant to heat.
If your switch is hot while you’re using it, this may indicate an underlying problem with your home’s wiring. A qualified electrician can inspect the wiring and recommend an appropriate course of action.
Circuit breakers
The circuit breaker, also called the breaker box or fuse panel (in apartments and older homes that still use fuses), is where you control your electrical service. Inside are a row or two of lever-operated switches. If one of them trips, it means that you are making too many demands on the circuit and need to move appliances or devices to other circuits. Breakers, which are rated by their normal current capacity and maximum short-circuit current they can safely interrupt, use mechanically stored energy to open their contacts and stop the flow of electricity.
If there is a short, such as the wires in your electrical outlets touching each other and causing a sudden surge of electricity, your breaker will trip to prevent it from heating up and igniting surrounding materials. The same is true for overloads, where you put too much demand on a circuit. Unlike fuses, which must be replaced when they blow, breakers are resettable.
Wiring
Electrical wiring is the system of conductors that transports electricity throughout a building. It is usually hidden from view behind walls, floors and ceilings but may also run through the roof. Wiring systems are different depending on the application. For residential purposes, insulated wires are typically in a metal or plastic conduit or tubing. Commercial facilities often have more complex wiring requirements that require large apparatus, frequent changes to equipment layout and corrosive environments.
Most electrical inspectors will inspect the service panel, lateral wires and the main service drop on a home or small business inspection. The service panel is the central hub of the entire electrical system and it must be properly inspected to ensure that all components are working correctly and that they are safe for use. When inspecting a service panel, look for spaces to add circuit breakers and remember that tools (like screwdrivers) should never be used on exposed wiring because they could cause an electric shock.
Arc fault circuit interrupters
AFCIs have electronic and electrical circuits that monitor currents coming into your home’s branch wiring. They look for characteristics unique to arcing and shut off the power when they detect them. This reduces the chance of fires caused by arcing. They are built into conventional circuit breakers and combine traditional overload and short-circuit protection with arc fault detection.
AFCIs are required for all new circuits in dwelling units and for any additional circuits when the existing wiring is upgraded or extended. They can save lives and property by detecting arcs that can cause fires before they cause serious damage. Like GFCIs, they are a safety feature that should be used and maintained properly to keep them working.