AdministratorWhich is better contactor or relay?
Relays are used in circuits that have load capacity equal to or smaller than 10 amperes, so spring load contacts are not commonly seen in relays due to their low load capacity. On the other hand, contactors have load capacities greater than 10 amperes which means that they can carry higher loads.
Is a contactor the same as a relay?
A contactor joins 2 poles together, without a common circuit between them, while a relay has a common contact that connects to a neutral position. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V.
Why use a relay instead of a contactor?
Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available. Contactors are switching devices used to control power flow to any load. Mainly used in control and automation circuits, protection circuits and for switching small electronic circuits.
What is the difference between a motor starter and a contact relay?
A contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. On the other hand, a starter employs overload relays to protect the motor from load surges by shutting it down to prevent overheating.
What’s the purpose of a contactor?
A contactor is a device that is for making and breaking an electrical power circuit. For example, we usually use a contactor for turning on and off an electrical motor.
Do contactors and relays matter?
Relays and contactors are very effective components for switching electrical power as long as they’re specified correctly, which means getting the right coil voltage (including AC and DC) and sizing the contacts correctly.
Why do you need a contactor?
Why are Contactors Used? Contactors are used for high power applications. They allow a lower voltage and current to switch a much higher power circuit, so they are generally larger and more heavy-duty than control relays, enabling them to switch higher power loads on and off for many thousands of cycles (Figure 1).
Why is a contactor used as a starter for motors?
The contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. A motor starter is simply a contactor PLUS an overload relay and is rated by motor HP or amperage. If there is no overload relay it is not a starter any longer. It’s back to being just a contactor.
What is the difference between a relay and a contactor?
Both relays and contactors are electromagnetic switching devices, relays are switching devices that work in the control loop, and contactors are switching devices that work in the main loop.
What are the auxiliary contacts of a contactor?
Some contactors come with additional auxiliary contacts that may be either NO or NC. These auxiliary contacts get activated along with the main contacts. Switching is achieved by energization and De-energization of the contactor coils.
When is a contactor the best option?
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.
What is the current carrying capacity of a contactor?
The current carrying capacity of the contactor’s contact tips are high and having ability to break large amount of fault current (around several kA). Since they are coming with the arc chute which is used to quenching the electrical arc during opening condition.