Motorcycle Relay Selection Principle
Motorcycle Relay Selection principle
The contact of the motorcycle relay has the following 3 in the form:
1, dynamic type (normally open) (H type) coil is not energized when the two contacts are open, power, the two contacts on the closed. With the word "H".
2, dynamic type (normally closed) (D type) coil is not energized when the two contacts are closed, after the two contacts on the power off. With the hyphenated phonetic prefix "D" said.
3, conversion type (Z type) This is the contact group type. This contact group has three contacts, that is, the middle is moving contact, up and down a static contact. When the coil is not energized, the movable contact and one of the static contacts are disconnected and the other is closed. After the coil is energized, the movable contact moves so that the original opening is closed and the original closed is disconnected and the converted purpose. Such a contact group is called a changeover contact. Use the word "z" for the word "z". When selecting a motorcycle relay, you should mainly consider the power supply type, the rated voltage and rated current of the contact, the rated voltage or rated current of the coil, the way of contact combination and the number of times and the release time. The following describes several commonly used motorcycle relay selection principle.
1. Selection of Electromechanical Motorcycle Relay
(1) current motorcycle relays according to the protection required by the load, the current motorcycle relay is divided into over-current motorcycle relays and undercurrent motorcycle relay two types.
Over-current motorcycle relay selection t parameter is the rated current and operating current, the rated current should be greater than or equal to the rated current of the protected motor, the operating current should be based on the motor work according to its starting current 1.1 to 1.3 times the setting. General winding rotor asynchronous motor starting current by 2.5 times the rated current to consider, cage-type asynchronous motor starting current by 5-7 times the rated current to consider. Select the over-current motorcycle relay operating current, should leave some room for adjustment.
Undercurrent motorcycles Relays are generally used for field weakening of DC motors and electric chucks. The main parameters are the rated current and the release current, the rated current should be greater than or equal to the rated excitation current, the release current setting value should be lower than the excitation circuit within the normal working range may occur the minimum excitation current, the minimum allowable current 0.85 times The Select the undercurrent motorcycle relay release current, should leave some room for adjustment.
(2) voltage motorcycle relays in accordance with the role of the control circuit, the voltage motorcycle relay is divided into over-voltage motorcycle relays and undervoltage (zero voltage) motorcycle relay two types.
Overvoltage Motorcycle relay selection of the main component is the rated voltage and operating voltage, the operating voltage can be 1.1-1.5 times the rated voltage of the system. Undervoltage Motorcycle relays commonly used as electromagnetic motorcycles relay or small contactor as its choice as long as the general requirements can be met, the release voltage value no special requirements.