1. What is a contactor
Contactors are divided into AC contactors (voltage AC) and DC contactors (voltage DC), which are used in electric power, distribution and electricity occasions. In a broad sense, a contactor refers to an electrical appliance that uses a coil to flow through a current to generate a magnetic field to close the contacts in order to control the load in industrial electricity.
Second, what is a relay
A relay is an automatic electrical appliance, which is suitable for making and breaking AC and DC small-capacity control circuits over a long distance. And in the electric drive system for control, protection and signal conversion. The input of the control relay is usually electricity such as current and voltage, or it can be non-electricity such as temperature, pressure, speed, etc. The output is the electrical signal sent by the contact action or the parameter change of the output circuit. The characteristic of the relay is that when the change of its input quantity reaches a certain program, the output quantity will change in a stepwise manner.
Three, the difference between contactor and relay
1. Contact capacity is different
Contact The contact capacity of the contactor is larger than that of the relay, the contact of the contactor is not lower than 10A, and the capacity of the relay is not more than 5A.
2. The design of the number of contacts is different
The number of contacts of the contactor is not designed in pairs, three groups of normally open contacts are the main contacts, plus The upper auxiliary contacts are normally open and normally closed. The number of contacts of the relay is designed in pairs, and there is no auxiliary contact.
3. Different functions
The function of the relay is to detect, convert and transmit signals, and its contacts compare the on-off current Small, commonly used in control circuits. The function of the contactor is to switch on or off the main circuit, and its on-off current is often used in the main circuit to make the high-power load energized or de-energized.
4. Different arc extinguishing devices
One of the most important differences between contactors and relays is that contactors have arc extinguishing devices, but relays do not.
5. Different additional products
More relay derivatives means more additional products. Contactors are relatively simple and there are no additional additional products. Relays can be designed as time relays, speed relays, counters, etc., but there are no contactors.
6. Use different
Sometimes contactors can be used as relays, but relays often cannot be used as contactors.
