Are Household Loads & Appliances Typically Wired in Series or Parallel?

Series and Parallel Circuits

• Electric circuits are wired in series, parallel or some combination of the two. A series circuit contains only one pathway for electric current to pass through. When electric current passes through each device in this circuit, the voltage drops across each device, and the amount of current is the same through each device. In contrast, a parallel circuit can have multiple pathways for electric current to travel through. Each parallel branch of the circuit has the same voltage; however, the amount of current flowing through each circuit branch may be different.

How Each Outlet Receives Power

• Each standard electrical outlet in a home will provide between 110 and 120 volts of electrical power. This is accomplished by wiring each outlet circuit in parallel. Each outlet circuit receives power from the electrical service box through its own circuit breaker. If the power through the circuit exceeds the breaker rating -- such as 18 amps of current attempting to flow through a 15-amp circuit -- the circuit breaker “trips,” thereby interrupting the circuit.

Return Wires and Grounding

• Each electrical outlet circuit is tied to two electrical bus blocks -- one “neutral” block and one “ground” block. Since electrical energy flows from a region of high voltage to a region of low voltage, the neutral block provides a low-voltage region for electricity to flow to in order to complete the electrical circuit. A ground block is used to provide an emergency pathway for the electricity to flow to. If there is a loose wire or short-circuit condition in one of the circuit branches, a properly-grounded outlet will dump the electrical energy to electrical ground. This will also cause the circuit breaker to overload and trip, thus providing an additional layer of protection against electrical shock.

Daisy-chained Electrical Outlets

• Additional electrical outlets may be added to an electrical circuit by daisy-chaining an electrical outlet to an existing electrical box. While it may appear that daisy-chaining a circuit turns the circuit into a series circuit, the opposite is the case. Daisy-chaining a circuit creates a new branch to that circuit, and the voltage of any devices plugged into that circuit will still be in the 110 to 120-volt range.