Relay and contactor difference - Solutions - Huaqiang Electronic Network

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

Photocoupler

Contactor QJX2-9511/380V is mainly used for primary circuit, it can pass large current (up to several hundred to more than one thousand A), relay is used for secondary circuit only through small current (a few A to More than a dozen A), to achieve a variety of control functions, relay contacts, there are many types, there are time relays, AC relays, Electromagnetic Relays, etc. are very fine, mainly used for secondary protection contactor current is large, Once for the ferromagnetic coil and the main contact. When the contact capacity of the relay does not meet the requirements, it can also be replaced by a contactor. When the contactor's auxiliary contacts are not enough, a relay can be added as an auxiliary contact to achieve various controls.
The design is different. It looks like a look at it. One is to emphasize the high current and short reliability for direct control of electrical equipment. The other is to control the relay or other auxiliary equipment (lighting valve body, etc.), emphasizing Functionality, the principle is the same, the design concept is different, just like the power cable and signal cable, you can also use the coaxial light bulb to light (as long as the pressure is enough), it can also supply power, such as the common electricity TV system; you can use a small-diameter power cable as a control cable. It's no different, but it's completely different from the field of use and the direction of design. There are two things. Two circles, only a small part of the intersection.
The relay has a typical contact capacity of 5A (of course, there are special ones), so that the contacts can increase the number and other functions (time, current, voltage, etc.), so that the interlock key control requirements can be achieved. Due to the small capacity of the relay, the contactor coil has a small capacity and is easy to use between the main control unit and the contactor. Contactors are primarily used for primary loop control equipment, so currents range from a few amps to thousands of amps. The arc extinguishing device has been added, and according to the use, there are AC contactor mechanical lock type AC contactor SC-N14/VS and DC contactor micro intermediate relay (DC coil) GMR-8MD. The use of the arc extinguishing cover is a method of the arc extinguishing device. Each contact of the contactor has a cavity, which has great advantages for arc extinguishing. The independent cavity is also an arc extinguishing device, and the relay is generally more The group contacts share a cavity, so the arc extinguishing performance is not good and cannot withstand large currents in the AC circuit. "Low-voltage contactor" does not make any sense to the arc extinguishing device. AC24V/20A AC contactor and AC380/20A AC contactor have the same arc extinguishing device. Even the AC24V/5A intermediate relay has arc extinguishing. Device because it has a separate cavity for each set of contacts. The crab has an arc extinguishing device that can break a large current. Generally it refers to more than 10A.