How to judge the quality of contactors

- Jul 24, 2019-

A contactor is a long-range control device that frequently turns on and disconnects the main circuit through electromagnetic mechanism movements. In the circuit, it is represented by the letter "KM" and usually "C" in the model. The contactors are divided into AC contactors and DC contactors, depending on the type of current passing through the contact.

Because the contactor belongs to the low-voltage distribution cabinet, the distribution box is more commonly used in a low-voltage electrical appliances, so we have a higher chance of contactcontact, the contactors installed in the distribution cabinet before, it is necessary to detect the good or bad contactors. In the event of a failure, it is also necessary to detect damage to the contactor. So how do we judge the quality of contactors?

When the contactor's internal coil is energized, the internal switch contacts are absorbed and the internal contacts are disconnected when the internal coil is disopened. Therefore, when the contactor is detected, it is necessary to detect the internal coil resistance and the resistance of the internal switch when it is open edgy and closed. Because it is good or bad to detect the contactor, the switch contact button at the upper end of the Anton contactor is required to force the contact to close for detection.

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Here's how to judge the quality of the contactors:

1. If the internal coil of the contactor is measured to have a certain resistance value, the internal switch in the closed state, its resistance value is 0, in the open state, its resistance value is infinite, it can be judged that the contactor is normal.

2. If the limit of the inner coil of the contactor is infinite or zero, the inner coil of the contactor is indicated to be bad.

3. If the contactor's switch is measured to be disconnected, its resistance value is zero, it indicates that the contact contact stoiding inside the contact is damaged.

4. If the contactor's switch is measured in a closed state, its resistance is infinite, it indicates that the contact points inside the contactor are damaged.

5. If the four sets of switches inside the contactor are measured, any set of damage, all indicate that the contactor is damaged. Because of the important role of contactors in low-voltage power distribution cabinets, in order to ensure their normal operation, we can judge whether the contactors are normal based on the above conclusions.