How many times is the electrical life of an AC contactor the mechanical life?

The electrical life of an AC contactor is generally 3-5 times the mechanical life. The electrical life is affected by contact wear, arc corrosion and contact welding; the mechanical life is affected by mechanism wear, spring fatigue and insulation aging.

AC contactor electrical life: 3-5 times the mechanical life

The electrical life of AC contactor is It refers to the number of switches it can work normally under the rated current, while the mechanical life refers to the number of switches it can work normally without carrying current. Generally speaking, the electrical life of an AC contactor is 3-5 times its mechanical life.

Cause:

Electrical life is affected by the following factors:

• Contact wear:During the switching process, Contacts will continue to wear, causing resistance to increase, causing heating and arcing.
• Arc corrosion:The arc generated during switching will corrode the contacts, causing their surfaces to be rough, further increasing the resistance.
• Contact welding:When the current is too large, the contacts may be welded together, causing the contactor to malfunction.

The mechanical life is affected by the following factors:

• Mechanism wear:The components in the switch mechanism will wear during movement, resulting in The movement is insensitive or stuck.
• Spring fatigue:The spring will gradually fatigue during the rebound process, resulting in a decrease in its restoring force and affecting the contact action.
• Insulation aging:Insulating materials will age over time, causing their insulation performance to decline and causing leakage or short circuits.

Since electrical life is more affected by contact wear and arc corrosion, it is usually shorter than mechanical life.

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