An appliance's electrical system can be compared with your home's plumbing system. Electrical current flows along wires in much the same way as water flows through pipes. Both electricity and water enter the home, are distributed through the house, do their "work" and then exit. With plumbing, water flows through a pressurized supply system. With electricity, current flows along "hot" wires. Current flowing along hot wires is also pressurized. The pressure of electrical current is called voltage. Larger supply pipes have a greater capacity to carry larger amounts of water. In the same way, larger wires can carry more current than small wires. Water is distributed for use by faucets, valves, and shower heads. Electricity is made available through receptacles, switches, and fixtures. Water leaves the home through a drain system that is not pressurized. Similarly, electricity flows back through neutral wires. The current within neutral wires is not pressurized and is said to be at zero voltage. Many people make the mistake of overlooking the neutral wires and connections during appliance troubleshooting. You would not ignore a leaking drain pipe in your wall! Don't forget to consider the neutral connections during your appliance repair. Your appliance won't work without them!
Circuit Basics... A Great Place To Start!
Circuit: A complete path from positive to negative through which electricity can travel.
Load: Component that converts electricity to heat, light, or motion. All loads restrict the flow of electricity while performing their work.
Conductor: Material through which electricity can flow. It will usually be a copper wire, and sometimes the chassis, or metal frame, on which the components are mounted.
Short: A circuit that offers no resistance to the current flowing through it. A direct short will cause a breaker or fues to blow and possibly start an electrical fire. A direct short is when electrons find an alternate path to a ground source that offers no resistance, such as water or a broken wire contacting the grounded metal cabinet of an appliance.
Shorted Switch: A switch that has fused in the closed position and can offer no resistance to the flow of current through it.
Open Switch: A switch that will not allow current to flow through it.
Closed switch: A switch that will allow current to flow through it.
ELEMENTS of a CIRCUIT
1. Power Source
A circuit must have a power source such as electricity supplied by a wall socket, battery, or generator.
Conductors are usually copper or aluminum wire, in some cases it can even be the frame on which the components are mounted.
The load is the components that do all the work through the use of resistance, such as a washer motor, heating element, or light bulb.
Controls are devices that control the flow of electricity to the loads. A control is usually some sort of switch that is operated by the user of the appliance, or operated by the appliance itself.