Industrial Motors: How to Safely Reset an Overload Relay on a Three-Phase Motor

When a three-phase motor shuts down unexpectedly, the overload relay reset has likely been triggered. This device protects your motor from overheating or drawing too much current. The process of learning how to reset overload relay three phase motor is simple once you understand the steps. 

In this article, you’ll learn why relays trip, how to reset them safely, what to check before restarting, and how Simply Buy supports you with expert guidance and reliable products.

What Is an Overload Relay?

An overload relay is a safety component built into motor starters. Its role is to disconnect power when the motor is overloaded. This prevents overheating, costly damage, and potential hazards.

• Thermal overload relays trip when a bimetal strip heats and bends.
• Magnetic overload relays react instantly to excess current.
• Electronic overload relays provide precise, adjustable trip settings.

If your thermal overload relay won’t reset, it usually means the motor is still hot or the original fault has not been corrected.

Schneider TeSys Overload Relays

Product: TeSys LRD33 Thermal Relay
Supplier: Global Industrial Supplier
Application: Motor & Circuit Protection
Compatibility: TeSys D contactors

View Product Details

Before Resetting an Overload Relay on a Starter

Resetting without inspection risks further trips or damage. Always check for:

• Proper ventilation and clean air passages.
• Correct motor load within rated limits.
• Balanced phase voltage.
• No mechanical faults such as worn bearings.

By inspecting these conditions, you make sure the reset overload relay process is safe and reliable.

Step-by-Step: How to Reset Overload Relay Three-Phase Motor

Here’s how to safely reset:

1. Cut Off Power

Always disconnect the motor from power before touching the relay.

2. Locate the Reset Button

Most relays feature a reset button, often red or black, positioned on the starter or relay housing.

3. Wait for Cooling

If the motor overheats, give it 5–10 minutes to cool. This is essential for how to reset thermal overload relay correctly.

4. Press the Reset Button

Once cooled, press and hold the button. A click indicates the reset is complete. Some relays allow manual or automatic reset settings.

5. Restart Motor and Observe

After confirming the cause of the trip is solved, restore power and restart the motor. Monitor performance closely during operation.

Troubleshooting: When the Relay Won’t Reset

If your thermal overload relay won’t reset, consider:

• Has enough cooling time passed?
• Are relay settings correct for your motor’s current rating?
• Is there a persistent issue, such as phase loss or mechanical jam?

If these problems remain, the relay may need replacement or professional attention.

Technical Support and Consulting

Sometimes overload tripping is not a simple fix. If you face repeated trips or can’t identify the root cause, Simply Buy’s technical support team is ready to help. Our experts can guide you in selecting the correct relay, checking settings, or troubleshooting persistent faults.

Contact our team at +65 9397 6747 or email marketing@simplying.com for quick assistance and expert consultation. Turning technical challenges into reliable solutions is what we do best.

Products and Services: One-Stop Motor Protection

Simply Buy offers more than overload relays. We provide a full range of motor protection products, so you don’t need to shop across multiple suppliers:

• Relays: Thermal, magnetic, electronic, and safety relays.
• Circuit Breakers: MCCB, MPCB, and smart breakers for industrial safety.
• Contactors and Motor Starters: Essential for safe and efficient motor control.
• VFDs and PLC Modules: For advanced automation and energy savings.

With global warehousing, fast delivery, and guaranteed genuine brands, Simply Buy is your trusted partner for industrial automation.

Conclusion

Knowing how to reset overload relay three phase motor is essential for keeping equipment safe and operations efficient. By following the right steps—cutting power, allowing cooling, resetting, and troubleshooting—you can restore motors safely and prevent repeat issues.

For reliable components and expert guidance, Simply Buy offers a complete range of motor protection solutions, including overload relays, circuit breakers, contactors, and VFDs. With genuine products, fast global shipping, and professional support, we make motor protection simple and worry-free.Contact us today for the latest quote and a seamless purchasing experience.