Contactors

A contactor is a device for switching or disconnecting an electrical connection. Contactors are used in      control circuits, eg as control contactors for medium power. Higher power equipment,      such as motors, are powered via power contactors.

Principle of contactors

Contactors and relays have a similar design, principle and characteristic parameters. When we bring it      voltage on the coil terminals, a magnetic field arises. The anchor with movable contacts is attracted.      The movable contacts are connected to the fixed contacts or interrupt the existing connections. For contactors      the main current contacts are switching. The auxiliary contacts are switching or expanding.      By changing the individual parts, such as a set of contacts or a coil, the contactor can be adjusted      for other voltages or equip other types of contacts. Contactors are divided into categories      by type of current and use. The relevant category must be indicated on the contactor.

Distribution of contactors

Depending on the application, we distinguish the contactors into power and auxiliary, depending on the type of switching current on      AC contactors and DC contactors. Inclusion in      use category makes it easy to choose the right contactor. The DC contactor is different      in a coil which is wound onto the magnetic core (hence does not have the electrical plates) which it has      north and south pole. The AC contactor has windings wound on the el. Sheets of the shape E and I.      When describing the contactor, the schematics and the actual contactors are called: A1, A2 -      control coil terminals; NO (Normaly Open) auxiliary switching contacts; NC (Normaly Closed)      auxiliary contacts.

DC contactors SU

The SU contactor is manufactured by Apen (now part of General Electric), which is a universal contactor for      jog AC and DC networks.

SU contactors are open contactors equipped with electromagnetic drive with Lp-5 forging coupling and electromagnetic discharge cavity. The SU contactor is equipped with an ŁP-4 auxiliary switch. The reciprocal positioning of the drive and contact systems allows for a minimum mounting surface, and the position of the jumper connection point in the axis of the main contact opening provides overall symmetry of the contact kinematics so that a combination of a normally open and normally closed contact is achieved.

Designation of contactors SU

• first digit - current size
• second digit - number of main contacts
• third digit - number of main contacts
• the letter Tr (if given) - traction