what is the diffrence between relay and contactor?

Answer 1

A relay is an electrical switch that opens and closes under the control of an outside electrical circuit

A contactor is a pparticualr type of relay. It is generally used in high current applications. contactors are used in heavy industrial settings. examples of applications of contactors are large pump motors, large AC compressors, extremely large heaters.

Most contactors use silver as the conductor because of the inevitable arcing and corrosion of the metal when the circuit is broken. Silver Oxide is still a decent conductor where as iron oxide is not.

Answer 2

Relay Contactor

Answer 3

1) A contactor is an electro-magnetic switching device (a relay) used for remotely switching a power or control circuit.[1] A contactor is activated by a control input which can be a lower or higher voltage / current than that which the contactor is switching. Contactors come in many forms with varying capacities and features. Unlike a circuit breaker a contactor is not intended to interrupt a short circuit current. Contactors range from having a breaking current of several amps and 110 volts to thousands of amps and many kilovolts. The physical size of contactors ranges from a device small enough to pick up with one hand, to large devices approximately a metre (yard) on a side. Contactors are used to control electric motors, lighting, heating, capacitor banks, and other electrical loads. 2) A relay is an electrical switch that opens and closes under the control of another electrical circuit. In the original form, the switch is operated by an electromagnet to open or close one or many sets of contacts. It was invented by Joseph Henry in 1835. Because a relay is able to control an output circuit of higher power than the input circuit, it can be considered to be, in a broad sense, a form of an electrical amplifier...

Answer 4

Relay is a device which can be set at aparticular range depending upon the capacity of a motor,it trips when overload is applied.
In healthy condition nc( normally closed) is in closed position,in overload condition it becomes no ( normally open ).



Contactor is a device which transfers 3 phase power,in which
moving & fixed contacts are present,moving contact with armature which is housed in a coil,230v / 415 v is applied accross the two leads wherin due to electro magnetic action the armature is pulled down ,thereby making the fixed and moving contacts to contact.
Contactors cannot be set at required value it is fixed range,it does not trip,one advantage is auxiliary contacts can be added for indication purpose.

Answer 5

Relay could be found on electic cabinet. One complet set could be use like one PLC automat. One relays coule be large or small. one realy could have more than 1 Normal closed or Normal open contacts.
there is one commande 24Vdc or 110vac ( or dif). to close it. there is no directe mecanique operation to close or open the contatc associed.
one contactor could be used for all voltae for exemple to close or open one ligne. the order could be mecanical.

Answer 6

Relays and Contactors are electromagnetic switches. The only
difference is that relays are usually used for low voltage
applications while contactors are used for higher voltage
application. Contactors usually have Overload protection.

Some examples that I can give (at least in Manufacturing of
Industrial Control panels):

-Relays are use as electromagnetic switches to control
certain parts of a circuit (low voltage application). A
better example would be such as if you want your circuit to
sound a horn when a certain abnormality is happening at a
certain period of time, then depending how you set up your
circuit, a specific relay will either open or close and you
horn will start making the sound.

-Contactors can be used for example, to start motors or a
number of motors that require a higher voltage in order for
the motor or motors start working. In the example that I
just gave, contactors work as starters.

Answer 7

Both are same. Time delay relay is contactor + timer.