How do switches control circuits

If one switch is up and one is down, the current reaches a dead end, no current flows and the bulb is off top left and bottom left. Note that the above color scheme does NOT reflect wire color. It is functional coloring intended to illustrate the voltage state of each wire segment. For more than two switches, one or more 4-way switches are added between the 3-way switches. A 4-way switch has two positions. In the first position, the contacts are connected straight through, so that the switch has no effect.

In position two, the switch cross connects the contacts on the left with the contacts on the right, in an "X" connection. Slide your mouse over the image to see the switch change state if you have Javascript enabled in your browser.

To view an animation showing how this works in a complete circuit, see How 4-way switches work -- an animation. This one-minute animation is the clearest illustration of the function of three- and four-way switch function. Don't worry about file size -- it should download in seconds even via a modem. Below is one example of a four-switch light circuit. This circuit also shows rough-in boxes, wire nuts, and proper color code. Note that the light can be placed anywhere in the return wire, shown above as white.

It may be as shown at the end of the run, but it may be between any pair of switch boxes as shown in a later figure , or even between the panel and the first switch box. You can use as many 4-way switches as you like. For the official word, consult the National Electric code. Here I will try to describe a bit of what the color coding is about, and how wires should be colored in lighting circuits and why.

Common practice in wiring a multiswitch circuit is to use two-conductor black and white cable from panel to the first switch, and then three-conductor black, red, white cable between pairs of switches. White denotes neutral, a current carrying wire that is bonded to ground in the circuit breaker panel. Black and red are used for "hot" conductors volts with respect to ground.

The previous figure shows a circuit that follows this convention. The NEC allows certain exceptions to this in lighting circuits, so that standard two-conductor black and white and three-conductor black, red, and white can be used, and used efficiently. Consequently, any use of this information should be done only in consultation with a qualified and licensed professional who can take into account all relevant factors and desired outcomes.

The information was posted with reasonable care and attention. However, it is possible that some information is incomplete, incorrect, or inapplicable to particular circumstances or conditions. We do not accept liability for direct or indirect losses resulting from using, relying or acting upon information in this blog post. Home White Papers Circuit Breaker vs. Circuit Breaker vs. Reliable short circuit and overload protection for all your branch and downstream device circuit protection.

Shop Miniature Circuit Breakers! Introduction Is it possible to use a circuit breaker as a switch interchangeably, or are they separate entities? But what are the differences between a switch and a circuit breaker? Making and Breaking There are two important parameters concerning the connection and disconnection of power for electrical utilities: Making Capacity — The maximum load current at start up. Breaking Capacity — The maximum fault current that can be interrupted.

A Switch An electrical switch serves the purpose of controlling the flow of electrical current within a circuit. A Circuit Breaker A circuit breaker is a safety device to prevent damage to motors and wiring when the current flowing through the electrical circuit supersedes its design limits.

However… Circuit breakers can be rated for switching duty for lighting circuits. Which will it be then? Can I use a Switch in place of a Circuit Breaker? Download PDF. Our Products. Cam Switches. Control Stations. Definite Purpose Contactors.

Disconnect Switches. DOL Starters. Electronic Timing Relays. The application of SPST switch is light switch given below and it is also called as a toggle switch. This type of switch has one input and one output. This light switch circuit controls one wire and makes one connection. The SPDT switch is a three terminal switch, one terminal is used as input and remaining two terminals are used as outputs. It joins a mutual terminal to one or the other of two terminals.

In the circuit below, when the switch A is closed, then the current flows through the terminals, but only light A will glow and light B will OFF. Her two circuits will be controlled through one source or one way.

The DPST switch consists of two poles that means it includes two identical switches located on side by side. This switch is operated by one single toggle, which means that two discrete circuits are controlled at a time through one push. The main purpose of this switch is to regulate a V appliance, where both supply voltages must be ON whereas the unbiased wire may be always connected. This switch is equal to two SPDT switches, it means two separate circuits, connecting two inputs of each circuit to one of two outputs.

The switch position controls the number of ways and from the two contacts each contact can be routed. At a time only two loads can be ON. The best example of this is, modeling of the railroad, that makes use of small scaled railways and trains, cars and bridges. The closed permits for the system to be switched at all times, whereas open permits for extra piece to be switched ON or triggered through the relay.