Why does the transformer suddenly appear high voltage

1.The fault of the external high-voltage line causes overvoltage, and the first phase is grounded.

2。One of the phases on the output side of the transformer is faulty to ground.

3.Internal faults in the transformer.

4。Distribution capacitor failure.

That's probably all there is to see the site.

There is a short circuit inside the transformer or resonance in the line.

I think the transformer in your factory should be a dry-type transformer.

First of all, if the transformer has been 500v, obviously, the insulation is damaged and the transformer has the coil burned out.

Secondly, it is not suddenly 500v, and then it goes back to 380v. The phenomenon here is more complicated.

Generally speaking, the external overvoltage such as lightning weather induces voltage, which leads to an increase in the power voltage of the plant.

Second, the internal overvoltage.

Overvoltage caused by a change in the internal operation mode of the power system. There are transient overvoltages, operating overvoltages, and resonant overvoltages. Transient overvoltage is due to the operation of the circuit breaker or the occurrence of a short circuit fault, so that the power system undergoes a transition process and then reaches a certain temporary stability of the overvoltage, also known as the increase of power frequency voltage.

Common ones are: no-load long-line capacitance effect (Ferrante effect). Under the action of power frequency power supply, due to the accumulation of capacitance effect of long-distance no-load lines, the voltage distribution along the line is unequal, and the terminal voltage is the highest.

Asymmetrical short-circuit grounding. When the ground fault of phase A of the three-phase transmission line is short-circuited, the voltage on phase B and C will increase. Overvoltage is caused by the fact that the electromotive force of the power supply has not been automatically adjusted in time when the transmission line is forced to suddenly throw off the load due to a fault.

Operating overvoltages are due to circuit breaker operation or occur suddenly.

The attenuation caused by short circuit is fast and the overvoltage lasts for a short time, and the common ones are: no-load line closing and reclosing overvoltage. Remove the overvoltage of the no-load line.

Cut off the no-load transformer overvoltage. Arc ground overvoltage. Resonant overvoltage is the overvoltage caused by the resonance of energy storage components such as inductors and capacitors with the power supply frequency under certain wiring methods.

Generally, according to the cause, it is divided into: linear resonant overvoltage. Ferromagnetic resonant overvoltage.

Parametric resonant overvoltage.

There are several reasons for sudden high voltage in transformers:1Load Variation:

When the load increases, the output voltage of the transformer increases accordingly. This is due to an increase in voltage due to the resistance and inductive reactance generated when the current passes through the copper wire of the transformer. If the load increases suddenly, the system cannot adjust the control signal of the feedback loop in time, which will lead to a vicious runaway and high voltage.

2.Transformer failure: A failure inside the transformer can also lead to high voltage.

For example, problems such as short circuit in windings and saturation of core magnetic flux can cause abnormal output voltage of transformers. At this point, the transformer needs to be stopped and the necessary maintenance required. 3.

Voltage fluctuation of the power supply grid: If the voltage of the power supply grid is unstable, it will affect the voltage of the transformer traveling companion, resulting in high voltage. Note that when the grid voltage is too high, the transformer's protective device should play a role to a certain extent, cutting off the equipment to avoid damage to the equipment or people taking the barricades**.

4.Incorrect operation of the equipment: Human reasons may also cause the transformer to output high voltage, such as configuration error, wiring error, operation error, etc.

Therefore, when using the transformer, it is necessary to follow the normal installation, commissioning and use procedures, and operate in strict accordance with the instructions. In any case, if there is an abnormal voltage output from the transformer, the use of the equipment should be stopped immediately and a professional technician should be called for treatment.

Summary. Dear users, there may be many reasons why the transformer suddenly appears high voltage. One of the possibilities is that there is a fault inside the transformer, resulting in a sudden increase in the output voltage of the transformer.

This fault can be caused by a short circuit in the transformer winding, damage to the insulation, etc. In addition, the input voltage of the transformer can increase suddenly, resulting in an increase in the output voltage. This can be due to voltage fluctuations in the power grid or other reasons.

It is important to note that the sudden appearance of high voltage in a transformer may pose a threat to electrical equipment and personal safety. Therefore, when a high voltage is found in a transformer, immediate measures should be taken to deal with it, such as cutting off the power supply or replacing the transformer. 

Dear users, there may be many reasons why the transformer suddenly appears high voltage. One of the possibilities is that the dry part of the transformer is infested with faults, resulting in a sudden increase in the output voltage of the transformer. This fault can be caused by a short circuit in the transformer winding, damage to the insulation, etc.

In addition, the input voltage of the transformer can increase suddenly, resulting in an increase in the output voltage. This can be due to voltage fluctuations in the power grid or other reasons. It is important to note that the sudden appearance of high voltage in a transformer may pose a threat to electrical equipment and personal safety.

Therefore, when a high voltage is found in a transformer, immediate measures should be taken to deal with it, such as cutting off the power supply or replacing the transformer. 

It is a short period of time to generate high voltage.

And it happens once in a while.

Pro, the sudden appearance of high voltage in a short period of time may be one of the following reasons:1Grid voltage fluctuations:

If the grid voltage fluctuates greatly, it will have a large impact on the transformer, making the transformer appear short-term high voltage. 2.Electrical equipment start-up:

For example, when a nearby device suddenly starts up and generates an inrush current voltage, it can also cause a short-term high voltage in the transformer. 3.Poor line contact:

Poor line contact may occur on the input or output tracking side of the transformer, resulting in sudden changes in current or voltage. 4.Transformer Internal Problems:

For example, problems such as local short circuit or poor contact inside the transformer will also lead to high voltage.

Summary. The tap-changer of the transformer is on the high-voltage side, if there is an open circuit phenomenon, it may be: 1. The internal lead is broken, 2. The tap-changer gear is not in place, 3. The coil is damaged If it occurs on the low-voltage side, it is likely that the internal fastening screw of the transformer's low-voltage lead is falling off The problem you said is too general to judge, please be more specific.

The tap-changer of the transformer is on the high-voltage side, if there is an open circuit phenomenon, it may be: 1. The internal lead is broken, 2. The tap-changer gear is not in place, 3. The coil is damaged If it occurs on the low-voltage side, it is likely that the internal fastening screw of the low-voltage lead of the transformer is destroyed and fell off The problem you said is too general to judge.

I'm still a little confused, can you be more detailed?

When the load switch has a phase hidden fuse fuse, the high-voltage side of the transformer is out of phase, which will cause the current of the other two furnaces to suddenly increase dramatically, and the temperature of the transformer coil will rise, resulting in unsafe phenomena such as transformer burnout. In order to protect the transformer from damage, when it is found that the load switch has a phase fuse blowing, the load switch should be immediately withdrawn from operation to find out the original.

Summary. The open circuit operation on a certain side of the power transformer generally refers to the following two situations. First, the power supply side of the double-winding transformer is live, and the load side circuit breaker has not been merged, which is the intermediate state and the time is shorter in the operation process; The second is the situation that a certain winding does not operate normally for some reason in the three-winding transformer, such as replacing the faulty two-winding transformer with a three-winding transformer.

There will be some problems when a certain side of the power transformer is operated open-circuited.

Dear, glad to have your question. The open circuit operation on one side of the power transformer will cause the problem of overvoltage, which is mainly divided into two situations.

You've done a great job! Can you elaborate on that?

The open circuit operation on a certain side of the power transformer generally refers to the following two situations. First, the power supply side of the double-winding transformer is live, and the state that the load-side circuit breaker has not been merged is the intermediate state and the time is shorter in the operation process; The second is the situation that a certain winding does not operate normally for some reason in the three-winding transformer, such as replacing the faulty two-winding transformer with a three-winding transformer. If a certain side of the power transformer is operated in an open circuit, there will be some problems with Changxin.

Summary. The reasons for burning the transformer due to too high voltage are as follows: 1. The power supply voltage is too high (more than 20% of the rated voltage of the transformer), which causes the core magnetic circuit of the transformer to be saturated, and the primary coil current is large, which causes overheating and burning.

2. Overvoltage directly causes coil insulation breakdown, short circuit, and burning. 3. The load current increases due to the increase of voltage, the transformer will be overloaded, and the long-term overload heating will also cause the transformer to burn out. 4. Other reasons.

Excuse me: My circuit always alarms: the voltage is too high. My transformer burned too. What's going on?

The reasons for burning the transformer due to too high voltage are as follows: 1. The power supply voltage is too high (more than 20% of the rated voltage of the transformer), which causes the core magnetic circuit of the transformer to be saturated, and the primary coil current is large, which causes overheating and burning. 2. Overvoltage directly causes coil insulation breakdown, short circuit, and burning.

3. The load current increases due to the increase of voltage, the transformer will be overloaded, and the long-term overload heating will also cause the transformer to burn out. 4. Other reasons.

How can my household voltage be too high? Is it the power supply company's problem?

It could be caused by a short circuit in one of your appliances.

Let an electrician test it.

There are cutouts on every road in my house, why don't you jump away?

The cutout switch doesn't jump and burns the transformer directly, right?

Right. 1. Under normal circumstances, the voltage is too high, and the fuse is theoretically burned first. So as to protect the transformer, which is the role of the fuse; 2. In this case, it is very likely that the insurance is too large, or the voltage is increased, but the limit of the fuse current has not yet been reached.

Therefore, the voltage is too high, which causes the transformer temperature to rise and burns out the transformer coil. There is no case of a blown fuse; 3. The fuse is generally protected and blown out in the event of an internal short circuit in the circuit or a large current impact. However, the current generally rises slowly, even at the critical point of the fuse.

Even if the temperature does not rise quickly enough, the fuse will not be blown out.

I understand. excluded.