Interlock is that the two contactors cannot be engaged at the same time, which is generally used in the motor positive and reverse circuit. If the two contactors are engaged at the same time, a short circuit between the power supply phase will occur.
The electrical interlock is that the normally closed contacts of KM contacts are connected in the coil loop of KM contacts, and the normally closed contacts of KM contacts are connected in series in the coil loop required for KM1 contact.However, if a contact contact is welded, the electrical interlock fails.Therefore, contactors with mechanical interlock must also be used in places with strict requirements.Two contactors intervene their respective auxiliary often closed contact reserves into the other’s control loop and lock each other, so that the two contacts can not engage at the same time.This loop is relatively simple, the general principle is to ensure that the motor is reverse can not be on, and reverse is not on, otherwise the suction contact will make three phase ac under the contactor form short circuit, so to lock in the loop, there is whether reverse or turn requirements can stop motor operation at any time, so stop button to series, start to be in parallel.
This is the two contactors KM1, KM2 control motor positive-reversal circuit.If KM1 and KM2 act at the same time, they will seriously short circuit the main circuit and cause an accident.Therefore, the normally closed contacts of KM1 are connected in series in the KM2 coil loop, and the normally closed contacts of KM2 are connected in the KM coil loop.Once KM is turning electricity, KM2 is impossible to get electricity, to objectively prevent short-circuit accidents.
Post time: Mar-03-2022
