Contactor old tripping? What is the reason why the main switch trips a few minutes after the AC cont

Contactors. Control protection circuit, for reference:

You said that there is no problem with the empty operation of these two motors, that is, there is no problem with no load, and the AC contactor will automatically trip after working for a while, which shows that the control loop is no problem, but the overcurrent protection action is caused by the overcurrent protection action, if your overcurrent protection is an ordinary thermal relay (thermal element);

First of all, you can first check whether the wiring of the upper and lower ports of the thermal element is loose, oxidized, etc., which causes heating phenomenon when the motor is running, check whether the setting current of the thermal element matches the rated current of the motor, if there is no problem, and then check the motor:

Turn off the power and spin the motor directly by hand and see if it's easy:

1.If it is sudden, disconnect the mechanical part of the motor and the motor connection (let the motor float) and then rotate the motor directly by hand, if it is still flare-up, please remove the motor and replace the motor bearing or bearing grease (I will not say more here); If it's easy, you're caused by a sudden attack on the mechanical part driven by the motor.

2.If it feels easy to rotate the motor by hand, then please find a clamp type ammeter to test the no-load current of the motor and the current when the load is working normally, to see if it is correct (the specific test method and current size will not be specific here), if there is a problem with the test current, then please remove the motor to check the motor problem (the specific inspection and treatment methods will not be said more); If the test current is still normal, then it can only be said that your thermal element is damaged, then replace it with a new one.

The contactor is old and tripped, and the reasons are as follows.

The contactor coil is faulty, or the contactor coil terminal is loose, or the contactor coil voltage is not enough to cause the old power trip.

Hello, the contactor is old and off Well, normally there should be two reasons, one is that the contactor is in a state of disconnection and reconnection, and second, your voltage is unstable, causing her to have his contact work not intact, causing the voltage to trip, thank you, I hope it can help you.

The thermal relay performs a protective action. Reason:

1: There is a problem with the motor and it is not found, and the load increases, resulting in an increase in the current.

2: Most likely is that the protection value of the thermal relay is not adjusted well, and it should be set according to the sign of the motor, (or take the current ordinary asynchronous motor, which is energy-saving design and cannot reach the maximum working current at all.)

3: If you exclude the above two points, that is, the thermal relay is too sensitive, there is often this situation on the scene, most of them are small factories or fake, you can change one.

The old tripping of the contactor means that the contact of the line is not good, and if the line contact is somewhat broken, this situation will also occur.

There are other high-power equipment on the same line, which starts from time to time, causing the voltage to fluctuate too much, and when the starting voltage is lower than 85 of the rated voltage, it will trip.

The line is too far, the voltage loss is too much, and the contactor armature suction is insufficient.

Hello, the old tripping of the contactor is a leakage place, and it is possible that the contactor is a problem, and it can be replaced.

If the contactor trips for a while, it is explained that the contactor may be caused by a short circuit or excessive current, which causes her to trip all the time.

This means that he is broken, or the spring inside is not up to standard, or it is caused by improper use, and it can be replaced.

The first is the release of the contactor coil, or the control of the empty trip? If the contactor coil is released, then check the secondary circuit, and if it is an empty trip, then check the main circuit.

The contactor trips old, it should be that the voltage is unstable, you can try to change the contactor.

I always trip, then one is caused by too high voltage, and one is a short circuit that occurs and you need to check the line.

The old tripping of the contactor may be the reason for your voltage instability.

My contactor will sometimes power off by itself when it is working normally, and the indicator light will also go off, I have checked the line and the motor are no problem, and the motor is not hot, but I just turn off the main gate and reopen it will continue to work, and the contactor is connected to a thermal relay under it, will it be the reason for it.

A few minutes after the AC contactor works normally, the main brake trips for basically two reasons

First, the load is too large, beyond the range that the main gate can bear.

Second, there is a problem with the main gate itself, such as the aging of the parts, which cannot withstand the rated load.

Another possibility is that the load changes after a few minutes of operation (such as leakage or short circuit, etc.); I don't know what you said about the main switch refers to the air switch or what, there are many kinds of air opening, there are no leakage protection, there are leakage protection, complex may also have phase loss protection, etc., need to be analyzed according to the situation.

The question you're talking about has basically nothing to do with the AC contactor itself. Problems that can occur with AC contactors are: contact burn (which can cause some or all of the contacts to be unable to be opened); The coil is either open or short-circuited (both will cause the AC contactor to not engage).

Some people always have the misconception that AC contactors will trip. In fact, the AC contactor itself is not overload protected, and the disconnection of the AC contactor is only related to the coil circuit (such as: the coil circuit is open or the coil is damaged).

That is to say, the overload protection action of the AC contactor must be realized by connecting the main loop to the overload protection element (such as overload relay, etc.) to control the coil circuit of the AC contactor.

The AC contactor trips a few minutes after normal operation, you touch it immediately when tripping, the shell of the AC contactor is hot, if the heat is more serious, then your fault is estimated to be caused by overload.

You can change to an AC contactor with a larger capacity.

The AC contactor trips as soon as it is engaged, indicating that the load connected under the main contact of the contactor has a short circuit, and the insulation resistance and ground situation on the load side can be measured with a multimeter.

AC contactors.

Abnormal suction refers to abnormal phenomena such as the AC contactor suction is too slow, the contact cannot be completely closed, and the iron core emits abnormal noise. Causes and treatment methods for abnormal suction of AC contactors.

1. Because the power supply voltage of the control loop is lower than 85% of the rated voltage.

The electromagnetic force generated when the solenoid coil is energized.

Small, the moving iron core can not be quickly sucked to the static iron core, resulting in slow or tight contactor sucking, at this time, the power supply voltage of the control loop should be adjusted to the rated working voltage.

2. The spring pressure is insufficient, resulting in abnormal contactor suction; The reaction force of the spring is too large, resulting in slow engagement; The contact spring pressure overtravel is too large, so that the core cannot be completely closed; The spring pressure and release pressure of the contact are too high, so that the contact cannot be completely closed. The solution is to adjust the spring pressure appropriately and replace the spring if necessary.

3. Due to the large gap between the moving and static cores, the movable part is stuck, and the rotating shaft is rusted or deformed, resulting in abnormal contactor sucking. During processing, the dynamic and static iron core can be removed for inspection, the gap can be reduced, the shaft and support rod can be cleaned, and the accessories can be replaced if necessary.

4. Due to long-term frequent collisions, the iron core plate surface.

uneven and expands outward along the thickness of the lamination, at which point it can be trimmed with a file and the core replaced if necessary.

5. The short-circuit ring is broken, causing the iron core to make an abnormal sound. In this case, a short-circuit ring of the same size should be replaced.

Summary. The contactor contactor trips as soon as it is engaged, you can remove the wire at the lower end of the contactor and then test it, if it still trips, it is a short circuit of the contactor. If it does not trip, the power line or motor on the load side has leakage and short circuit.

Hello, the contactor trips generally because the contact of a certain component is broken at the head of its control loop. Or the power cord is too small or the load is too large, causing the contactor coil to be under-voltaged. Recommendations:

Find a professional to repair it, if you are not particularly proficient in this, don't go or count it yourself.

The contactor contactor trips as soon as it is sucked in, you can remove the wire at the lower end of the contactor and then test the source of the edge, if it still trips, it is a short circuit of the contactor. If the base does not trip, it is the power line or motor on the load side, and there is a leakage short circuit.

The reasons for the old tripping are as follows:1. The tripping caused by the short circuit of the electrical appliances can be checked one by one, and the damaged electrical appliances can be repaired to solve the problem;

2. The circuit load is too large, when multiple electrical appliances are used in the same lease, it will cause overload, and the meter switch will automatically trip, and you can buy a higher power meter;

3. Voltage instability, voltage instability is very common, and only need to buy a Qinglu voltage regulator to solve it.

It may be a short circuit in the line, it is recommended to check it.

1. The line is short-circuited. Air switch.

It can be used for a while, and the situation that occurs is that the air switch trips.

But leakage protectors.

There is no action. So this kind of is a conditionally triggered short-circuit.

2. The air switch does not match. This circuit uses high-power electrical appliances (air conditioners, washing machines, water heaters, bath bombs, etc.), but it is equipped with a small load and an empty travel rate.

It is easy to trip. If the total power exceeds the rated range for the empty opening, then tripping is also possible. At this time, it is necessary to replace the air opening with higher load power.

3. Loose wiring or poor contact of the wire. This situation is also one of the common reasons for air tripping, you can cut off all the air opening, use a screwdriver to check the air defense quietly open the wiring one by one, and tighten one by one, just in case.

4. Circuit breaker damage is rare, you can disconnect the circuit breaker to remove the load first, if it still can't be closed, it means that the circuit breaker is damaged, then you can replace the circuit breaker of the same model.

Kiss. Hello, I am happy to answer for you: what is the reason for the tripping of the pump contactor Answer: If it is an empty open leakage switch tripping, then it may be that the pump is overloaded, short stove and road, leakage, and empty opening rated current selection is small; If the contactor is disconnected and tripped, it may be an overload (thermal relay hidden round star) tripping or the thermal relay is not properly set.

There are many reasons for the overload of the submersible pump to trip, such as: the cavity pump is blocked, the bearing is worn, the oil is lacking, the valve is closed, etc.

Summary. If the conditions permit, adjust the power supply voltage of the transformer, generally the normal tap-changer is in the second gear, and can be adjusted to the third gear as needed. You can consider taking a step-down start, such as a star angle start.

You can also install a reactive power local compensator (capacitor) next to the motor, and the motor stator lead wire in parallel, and the power of the general compensator (thousand shortage) can be selected according to the rated power of the motor 30. Thickening the wire diameter of the cable can effectively increase the current conduction and reduce the voltage drop. If you choose CJ12 contactor, you can readjust the reaction force of the armature spring and the initial and final pressure of the H main contact spring.

Hello kiss The problem of AC contactor tripping is too much voltage loss, and the suction of the contactor armature is insufficient.

There are many reasons why an AC contactor trips. There are other high-power equipment on the same line, which starts from time to time, causing the voltage to fluctuate too much, and when the starting voltage is lower than 85 of the rated voltage, it will trip. The line is too far, the voltage leakage loss is too much, and the suction of the contactor armature is insufficient.

For example, the 22kw motor chooses a 4mm2 cable, which causes the voltage to be too low due to the insufficient current conduction of the cable. The CJ12 contactor reaction force spring is adjusted too tightly, and the voltage will trip if it fluctuates slightly.

If the conditions permit, adjust the power supply voltage of the transformer, and the normal tap-changer is generally in the second gear, and it can be adjusted to the third gear according to the need to carry it. You can consider taking a step-down start, such as the star angle debate booth start. You can also install a reactive power local compensator (capacitor) next to the motor, and the motor stator lead wire in parallel, and the power of the general compensator (thousand shortage) can be selected according to the rated power of the motor 30.

Thickening the wire diameter of the cable can effectively increase the current conduction and reduce the voltage drop. If you choose CJ12 contactor, you can readjust the reaction force of the armature spring and the initial and final pressure of the H main contact spring.