Electrical Circuits - Electrical 101
Search

Copyright 2018 Electrical101.com All Rights Reserved.

Sitemap
Electrical101

Sitemap

Terms of Use

Privacy

About

Electrical Circuits

Electrical Panel and Circuit Wiring Diagram

Electrical Panel

120 V

Neutral

240 V

A & B

phases

Two pole

circuit breaker

for electric oven, dryer and/or air conditioner

Ground bar

Question or Comment?

Household Circuits Diagram

These diagrams show a typical circuit path from the power company through the main electrical panel and to the outlets (light sockets, switches, and receptacles).

120V A&B Phase

From power company

Neutral

Electric meter

Ground and neutral are connected together

in one location only, at the neutral point either at the power company transformer or in the main electrical panel.

The potential difference between the A phase and B phase is 240 volts.

Main breaker

Neutral

bar

Electrical Panel Diagram

NM cable

Electrical Panel

A phase

power bus

To ground

B phase

power bus

Ground

Circuit Capacity

Circuit capacity depends on the voltage and current ratings of wires and circuit breakers. When a circuit is rated for 15 amps, the wires and circuit breakers must be rated for at least 15 amps. The circuit is rated for the lowest current rating of wire or circuit breaker. For example, if the wire is rated for 15 amps, the circuit should not have a 20 amp breaker even if the breaker trips frequently.

It is very important that a 20 amp (or higher) circuit breaker NOT be used on a circuit with a wire rated for 15 amps or less.