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The Mystery of Contactor Chattering and How to Prevent It

Are you facing the frustration of chattering contactors wreaking havoc on your electrical systems?

Chattering, the rapid opening and closing of a contactor, can cause a host of problems, from increased wear and tear to overall system instability. But fear not, for we're here to shed light on the primary causes of chattering and g

uide you on how to prevent this disruptive phenomenon.

The Culprits Behind Contactor Chattering

Chattering contactors are often a result of several underlying issues. Identifying these issues and addressing them head-on can help you put an end to the relentless cycle of contactor chattering.

1. Voltage Mismatch: Bringing Harmony to Coil


One of the leading causes of chattering is the discordance between rated coil voltage, frequency, and the source voltage. Imagine connecting a 220V coil to a 110V source – a recipe for disaster! To avoid this, make sure the coil voltage matches the source voltage and frequency. When in doubt, it's better to adjust the coil to fit the source voltage than to risk continuous chattering.

2. Voltage Fluctuations: Keeping the Current Flow Steady

Low voltage and rapid voltage drops can induce chattering in contactors, especially when starting up motors. If the voltage drop exceeds 35%, the contactor can get trapped in a loop of opening and closing. This relentless cycle, occurring every 20 to 50 milliseconds, can be a headache to deal with. To tackle this issue, regularly maintain your systems and consider using an oscilloscope for accurate voltage drop measurements.

3. Connection Complications: Ensuring Stable Connections

Loose, leaky, or inadequate connections can all trigger chattering. Connections that are too small, distant from the source, or subjected to excessive vibrations can lead to the dreaded chattering effect. Take care to inspect and improve the connections, ensuring proper screwing, soldering, and torque application. Additionally, make sure not to overload your system with simultaneous motor startups, which can further exacerbate the issue.

4. Vibration Vulnerabilities: Averting Oscillations

Contactor connections that are easily jolted by vibrations can cause chattering. A shaky relay or an unstable pressure switch can set off a chain reaction of chattering events. Address these vulnerabilities by strategically placing relays, switches, and limit switches to avoid undue vibrations. Be aware of pressure and preparation issues that could cause vibrations, and take necessary measures to counteract them.

5. Installation Insight: The Art of Proper Setup

Even the installation of the main contactor body can influence chattering. If the control board's structure or the main body's placement encourages bouncing, chattering is likely to follow. Consult the product catalog for precise installation instructions, ensuring that you're mounting everything correctly to prevent unwanted vibrations and chattering.


As frustrating as contactor chattering can be, understanding its causes and implementing preventive measures can bring stability and harmony back to your electrical systems. By addressing voltage mismatches, fluctuations, connection concerns, vibration vulnerabilities, and installation intricacies, you can bid farewell to the era of chattering contactors. Remember, a well-maintained and correctly configured electrical system not only saves you time and resources but also keeps your operations running seamlessly.

Get Connected for Expert Insights!

Contactor chattering might seem like a daunting challenge, but armed with knowledge and the right approach, you can conquer it and restore stability to your electrical systems. We've unveiled the primary causes of chattering and provided you with valuable preventive strategies to put an end to this disruptive phenomenon.

For more in-depth insights, expert advice, and tailored solutions, don't hesitate to get connected with us.Yo ur operations deserve the best, and we're here to make it happen!

For more information, you can contact us at, Sunitha P, Marketing Manager, LS ELECTRIC, 8061429108.

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