Three-phase motor that trips.

Is your three-phase electric motor tripping the breaker? Find out why and how to restore power to your system.

If you're reading this article, it's because one of your three-phase motors is causing your system to trip. Unfortunately, this can happen without warning. You're about to leave for the weekend or finish work, and your colleague calls to tell you that a three-phase motor tripping the breaker is causing a problem with your system. This type of fault always occurs when you need your system most.

This type of fault is one of the most common issues with a three-phase motor. This problem can be caused by various reasons.

Your three-phase electric motor is likely tripping the breaker because it's defective, overloaded, has an insulation fault, is running on two phases, has a mechanical problem, or is protected by a faulty circuit breaker.

Whether your motor is installed on a pump, a fan, a compressor, a gear reducer, or a machine tool, it doesn't change the problem.

We will elaborate on each fault and provide you with solutions that will help you understand why your three-phase electric motor is tripping the breaker and how to correct this problem.

Your three-phase electric motor is defective.

In most cases, an out-of-service three-phase motor will cause your system to trip.

The winding of an electric motor must not be in contact with the motor casing. A short circuit can occur in case of faulty wires or damaged components, leading to a direct fault and consequently tripping the motor's starting circuit.

This type of fault can occur after a jam on your machine, an overload, a mechanical problem, or abnormal humidity in the motor.

When the winding is defective, it is best to contact a qualified specialist with in-depth technical knowledge. A qualified specialist will be able to assess the cost of repairing your motor and tell you the most cost-effective solution for you: either perform repairs or opt for the purchase of a new three-phase motor.

You can also consult our article to find out how to check a three-phase motor.

Your three-phase electric motor is overloaded.

An overload on a three-phase electric motor occurs when it is strained and consequently draws more current than expected. Several factors can cause this overload:

- Excessive load: If the mechanical load on your motor exceeds its nominal capacity, this will lead to an overload. Furthermore, if your application requires much more energy than your motor can produce, it will be under excessive load. It is therefore important to check if your motor is suitable for your activity.

- Incorrectly calculated supply voltage: If your supply voltage is lower or higher than normal, this can lead to motor overheating, overconsumption of energy, or motor overload. The electric motor can be damaged, which will result in a loss of performance and reduce the lifespan of your motor. You can measure your supply voltage with a voltmeter or multimeter and compare it with the voltage indicated on your three-phase motor's nameplate. If you have difficulty reading a nameplate, here is an article that will simplify the task for you: Understanding a nameplate.

- Improper use of your electric motor: If the motor is used in an application for which it is not designed, this will lead to an overload and thus damage your motor and your application. Don't panic, Dymatec Industries helps you select the right three-phase motor. The entire team is available to provide you with the necessary information. You can find our article On which applications should I install my three-phase motor?

Worn bearings or a mechanical problem:

The bearings on your motor allow the rotor to rotate freely. If one of the bearings is worn, massive vibrations and an excessive load will be caused on the three-phase motor, leading to it tripping.

If one of your bearings is damaged, it must be replaced immediately to avoid complete motor failure. You should not ignore a bearing problem on your motor, as this can lead to higher repair costs or even render your three-phase motor unusable.

The insulation of your three-phase electric motor is faulty:

What is insulation on an electric motor? It's a layer of varnish that protects your electrical wires and thus prevents short circuits and motor tripping.

Insulation can be damaged with age, humidity, or exposure to high temperatures. Faulty insulation can lead to current leaks. These can trip the differential, which is designed to automatically cut off the motor's power supply in case of leaks.

If you notice faulty insulation on your motor, you should consider having your motor serviced, rewound, or completely replaced.

Your three-phase electric motor has a faulty circuit breaker:

Your circuit breaker can trip in case of overload, short circuits, or wiring problems. However, it is possible that it is just the circuit breaker itself that is faulty and causing a trip. In such cases, there is no need to panic, you just need to replace your circuit breaker. You can consult an electrician to check if your circuit breaker is suitable for your three-phase electric motor.

Unbalanced loads on your three-phase motor's phases:

A three-phase motor that trips the breaker may have an imbalance on one phase, meaning it is operating on two phases instead of three.

If a load is uneven on one of your phases, it will cause a trip and sometimes make the motor "growl."

If an abnormal noise comes from the motor, it is said to "growl"; this fault is often due to a missing phase.

Load imbalance can be caused by:

- A defective coil on one phase.

- A bad connection on one or two phases.

- A bad terminal connection.

- A faulty bar in the rotor.

- A defective fuse.

It is advisable to consult a specialist quickly to avoid further problems with your motor: overheating, premature wear, loss of power, etc.

As you will have understood, a problem with your motor should not be left unattended. It is preferable to consult a specialist when your three-phase electric motor trips the breaker to avoid further damaging the motor.

You can find all our three-phase motors via the following link: Three-phase motors.

Do not hesitate to contact us if you have any doubts; we are available by email or phone to meet your needs.