0
No it is not hard to tell them apart. A Single Pole Single Throw switch will go directly from the on position to the off position breaking the circuit. This is the type of switch that is used in homes for lighting control. A Single Pole Double Throw switch will usually have a stop indent which is the off position mid way through the throw. This is the switch that is used for a transfer switch when using a stand by generator in the system. The full up (on) position is usually connected to utility power. The full down (on) position is usually connected to the stand by generator.
Still curious? Ask our experts.
Chat with our AI personalities
Vivi
Jordan
BlakeIt is not difficult to differentiate between a SPST (Single Pole, Single Throw) and a SPDT (Single Pole, Double Throw) switch. A SPST switch has one input and one output, while a SPDT switch has one input and two possible outputs. This difference can typically be visually identified by looking at the number of terminals on the switch.
Add your answer:
Earn +20 pts
What are the uses of spst and spdt switches?
SPST (Single Pole, Single Throw) switches are commonly used to control a single circuit, either turning it on or off. SPDT (Single Pole, Double Throw) switches can control two separate circuits or functions, allowing for the selection of one of two options. Both types of switches are used in various electronic and electrical applications to control power distribution and circuit function.
What does com mean on a light switch?
In a situation where there is only one switch controlling the light or lights you normally use a spst (single pole single throw) switch that has only two connection terminals. This type of switch either connects or disconnects the two wires that are connected to the switch's terminals depending upon the position if the switch lever. The com terminal on a light switch means that it is a three way or the kind of switch used where there are two or more switches that controll the same light or lights. The three way switch is a spdt ( single pole double throw) . If you look closely you will find this designation somewhere on the switch. On the spdt switch you have three terminals, a common and two branches. In one postiion the common connects to one branch and in the second position the common connects to the other branch. If you are trying to install this switch in a situation where there is more than one switch controlling the light you must have the ability to correctly identify the common wire; if you can't do that you need help from someone who can do that correctly.
What else is a single pole switch known by?
This is the typical light switch in your home that controls a single light from a single location. Sometimes you might see it described as SPST or single pole single throw.
How many line conductors are installed between the switch and light fixture?
One. A typical "two way" ON-OFF light switch is a Single Pole Single Throw (SPST) switch with two terminals. It is wired in series with the fixture: that is, the power circuit is routed from the breaker to one side of the switch. The other side of the switch is connected to the "phase" or "power" terminal of the fixture. In a 115VAC single phase circuit, the other terminal of the fixture is connected to neutral. A "three way" switch circuit consists of two switches in different locations, each of which is a Single Pole Double Throw (SPDT) switch with three terminals. A typical use would have one switch at the top and the other at the bottom of a set of stairs. For the sake of clarity, we can label the "common" terminal on a SPDT switch the "C" terminal. This terminal is internally connected to one of the other two terminals, call them "A" and "B", depending of the position of the switch. A three way switch is connected with the circuit breaker connected to the "C" terminal on either switch. Conductors connect the "A" terminal on one switch the the "A" terminal on the other switch and the "B" terminal on one switch the the "B" terminal on the other switch. The remaining "C" terminal is connected to the "phase" or "power" terminal of the fixture. The other terminal of the fixture is connected to neutral. Note that, in either case, there is no neutral wire connected to the switch. Ground conductors do connect to the chassis of the switch box and the fixture, but they do not carry current and do not affect the operation of the circuit.
What type of switch has an on off position with one pole and one contact?
A single-pole, single-throw (SPST) switch has an on-off position with one pole and one contact. It is the simplest type of switch where the circuit is either connected (on) or disconnected (off) with just one path for the current to flow.
