Why relay is used with contactor?
Relays are used to control contacts of an electrical circuit due to a change of parameters or conditions in the same circuit or any other associated circuit. Contactors, on the other hand, are used to interrupt or establish connections in an electrical circuit repeatedly under different conditions.
How does a relay actually works?
In a normally open relay, power flows through an input circuit, activating an electromagnet. This generates a magnetic field that attracts a contact to join with the second, larger circuit, allowing current to flow through.
What is a contactor and how does it work?
A contactor is an electrically-controlled switch used for switching an electrical power circuit. A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagnet controlling a 230-volt motor switch.
What is basic difference between relay and contactor?
Control Relay: It is a device through which contacts in one circuit are operated by an alteration in conditions in the same circuit or in associated circuits. Contactor: It is a device which is used for repeatedly establishing and interrupting an electric circuit under normal conditions.
What is the purpose of contactors?
A contactor is a special type of relay used for switching an electrical circuit on or off. They are most commonly used with electric motors and lighting applications.
What is difference between relay and switch?
You are correct that a relay is basically just a switch, but it’s a switch operated via remote control, so to speak. A regular switch controls electrical current by connecting or breaking the path of either the positive side of a circuit (most common) or the negative side of a circuit.
How are contactors similar to a control relay?
This is similar to how control relays work, except that with contactors you generally have larger coils, bigger contacts, and can control much larger loads than a typical relay could handle.
How are relays used in an electrical circuit?
How Relays Work. Relays are switches that open and close circuits electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. As relay diagrams show, when a relay contact is normally open (NO), there is an open contact when the relay is not energized.
How does a contactor work in a circuit?
They operate similar to relays, but often times deal with more voltage, higher amperage, and have more input and output options. Contactors are extremely useful pieces of equipment that allow switching of several different circuits at the same time.
What happens when a contact on a relay is opened?
This normally-closed contact is usually connected in series with the relay coil, so that when it opens the relay will automatically de-energize, thereby shutting off power to the motor. We will see more of this overload protection wiring in the next chapter.