What is the difference between a relay and 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.
Is contactor a relay?
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.
Is magnetic contactor a relay?
Magnetic contactors are a form of electrical relay found on most electrically powered motors. They act as a go-between for direct power sources, and high-load electrical motors in order to homogenize or balance out changes in electrical frequency which may come from a power supply as well as to act as a safeguard.
What is the purpose of an auxiliary contact?
Auxiliary contacts are mainly used to signal switching or malfunction states, for interlocking circuits or logic and sequence controls with low to high loading. Many protection or control devices have additional auxiliary contacts.
Why do contactors chatter?
Low voltage to the contactor coil will allow the contactor to chatter. Contactor chatter can also occur due to chattering switches or loose connections in the control circuit. A low voltage situation can also occur due an unbalanced loading of the motor.
What is difference between contactor and circuit breaker?
The main difference between electrical contactor and circuit breaker is, a contactor is an electrically controlled switch that makes contact to connect the load with the power supply whereas a circuit breaker is an electrical protective device that breaks contacts to disconnect the load from the power supply during a …
What happens if you don’t use a relay?
This can cause premature failure of the switch. Another required use for relays is when you’re installing an electric cooling fan. If you wire direct, without a relay, all of the additional stress from the fan will be placed on the switch, leading again to early failure.
What makes a contactor trip?
What’s the difference between a relay and a contactor?
Relays are generally classified as carrying loads of 10A or less, while a contactor would be used for loads greater than 10A, but this definition, while simple, gives an incomplete picture. It leaves out any physical differences, or standards. 2.
What are the interlocking contacts on a relay?
The main contact can have interlocking contacts to indicate the opening and closing of the main contact. Relays are generally used in electrical control circuits to expand the contact capacity of miniature or small relays to drive larger loads.
What is the symbol for the contactor wiring method?
The graphic symbol of the contactor is shown in the figure below, and the text symbol is KM. Wiring method of contactor
When to use a contactor in a circuit?
For any circuit where an overload condition could occur, and a failure to de-energize the circuit will create a dangerous condition, then a contactor is likely the best choice because of the additional safety features.