What is the difference and relationship between overload, overload, overvoltage, and overcurrent?

These concepts are all interconnected, but artificial distinctions are helpful to understand.

Generally speaking, it refers to electrical equipment or power supply equipment, and these concepts are used, and these concepts are used to distinguish between them.

Capacity, voltage, current.

The overload generally refers to the power supply equipment exceeding the rated capacity.

Finish. Overload: Generally refers to the electrical equipment exceeding the rated capacity.

Overcurrent: It means that the current of the power supply equipment or electrical equipment exceeds the rated current.

Finish. Overvoltage: It means that the voltage of the electrical equipment or power supply equipment exceeds the rated value.

A few points to note: 1: Some devices are both point-of-use devices and power-supply devices. For example: transformers (so both overload and overload can be said).

2: s = root number 3*u*i (single-phase is u*i).

According to the formula, the overcurrent does not necessarily exceed the rated capacity, and the overvoltage does not necessarily overcurrent or capacity, but the overvoltage will cause equipment insulation damage.

Sometimes overvoltage will lead to overcurrent and it must be overloaded, so you can understand how to call it!

When the voltage exceeds 10% of the rated voltage, it begins to enter the process of overvoltage, which can cause overload. When the load exceeds the power supply capacity, it enters the overload process, and the danger lies in the degree of overload.

All overloads are manifested as excessive overall circuit currents.

Overload itself is overload, which leads to overcurrent, and overvoltage leads to overcurrent. The voltage and current exceeding the carrying capacity of the circuit are also called overload, and the overvoltage will inevitably lead to the overcurrent, and the overcurrent is not necessarily caused by the overvoltage.

Overload is when the load current of the circuit exceeds the rated value. In the case of overload, the main aspect of the contradiction is the current problem, to consider the maximum carrying capacity of the circuit to the current, the general overload time can not be too long, otherwise it is easy to heat up and burn out the electrical appliances or circuits. The voltage drop of overload is also increased relative to normal operation, but it is not the main contradiction of the problem.

Overcurrent is the current that exceeds the rated current. The loop current that is greater than the rated load current of the circuit conductor is overcurrent. It includes both overload and short-circuit currents.

The distinction is that the overcurrent before the insulation damage of the wild rental circuit is called the overload current; The overcurrent after the insulation is damaged is called the short-circuit current.

The protection purpose of the two is different, overcurrent protection is for short-circuit fault protection, overload is essentially for the heat capacity of the equipment itself, and for high-voltage transmission lines, it is still necessary to stabilize the system. The action exit of the two is also different, the overcurrent protection is aimed at the short-circuit fault of the ridge, and the final outlet is to isolate the protection range, and sometimes the recloser will be started for the line; In case of overload, the recloser will generally not be activated, and sometimes there may be a design with a coupling.

Overload, overload, and overcurrent all have the same meaning and will cause the temperature of the appliance to rise. Among them, overload and overload generally exceed the rated value not much, and the allowable operation time is longer, while the overcurrent, including fault (short circuit) overcurrent, generally exceeds the rated current a lot, and is not allowed to run for a long time. Overvoltage refers to a lot of voltage exceeding the rated value, including lightning overvoltage and operating overvoltage, etc., the process is very short, but there is damage to the insulation of electrical equipment, and even leads to insulation breakdown.

Overcurrent is a fault in the line, but it is not within the protection range of quick break, and it is generally single-phase grounding, etc., which requires tripping within a certain period of time. Overload is the overload of the line, which is not a fault nature, but only an alarm signal, which generally appears in the summer, when the factory starts, and everyone is using air conditioning, which exceeds the rated load of the equipment. When the load is too high, the service life of the primary equipment will be shortened, especially when the transformer is overloaded.

The purpose of protection is different, the overcurrent protection is against short-circuit faults, and the overload is essentially against the device.

For high-voltage transmission lines, it is still necessary to stabilize the system. The purpose of protection is different, and the principle of selective coordination is different. Overcurrent protection is coordinated with the protection section of the adjacent device for short-circuit faults, while overload is coordinated with the thermal load capacity of the equipment.

The action outlet of the two is also different, the overcurrent protection is aimed at the short-circuit fault, and the final outlet is to isolate the protection range, and for the line, sometimes the recloser will be started; In case of overload, the recloser will generally not be activated, and sometimes there may be a design with a coupling.

The overcurrent is mainly for the electrical equipment (load side), and the overload is mainly for the power equipment (such as transformer) on the grid side.

Overload is generally calculated by the current setting of the electrical load;

The overcurrent is calculated by setting the short-circuit current at the end of the power supply line;

Both of these have the same effect in terms of electrical damage, and both will burn electrical appliances, such as TVs, motors, etc. But there are also differences, mainly because the overload burned equipment caused by overvoltage will be very fast, and the general overcurrent is relatively slow to burn the equipment, usually the temperature rise of the electrical equipment is too high, if not dealt with in time, or to burn the electrical appliances.

If from the electrical principle, the high-voltage overload is explained by Ohm's law at a glance, and the overcurrent is mainly operated by the current of the electrical appliance in a state that exceeds its rated current for a long time.

There are two main differences between overcurrent protection and overload protection.

1. The setting action value is different. The fixed value of overload protection is much lower than that of overcurrent protection, but it is greater than the normal load, which prevents the equipment from running overload, and a certain delay is added in order to avoid the starting current of the equipment. Overload protection can also be used as a backup to overcurrent protection when for some reason the overcurrent protection is rejected.

2. The action time is different. In order to avoid the starting current of the device, a certain delay is added. Overload protection can also be used as a backup to overcurrent protection when for some reason the overcurrent protection is rejected.

Produce different hazards:

1. The overcurrent reflects the fault state of the transformer, and the value is large, and the function is tripping; Overload protection is to remind the transformer of overload, generally only send signals, lock on-load voltage regulation, start air cooling, etc. The role of transformer overcurrent protection and overload protection is completely different.

2. Overcurrent is divided into several situations, overload will cause overcurrent, but faults such as grounding or short circuit of electrical equipment will also cause overcurrent, which may not only cause burning of metering devices and electrical equipment, but also cause great danger to people.

3. Overload refers to the actual use of the load exceeding the rated load, mostly due to the increase of electrical equipment, exceeding the approved use capacity of the power supply enterprise or exceeding the design capacity of the electrical circuit, which will cause the burning of metering devices and electrical equipment.

Overcurrent is for a certain electrical appliance or a certain circuit element, the harm caused is that it is possible to damage or burn the electrical appliance or circuit element, and the overload is for the circuit, the total power of the electrical appliance exceeds the carrying capacity of the circuit, resulting in excessive current in the circuit and damage the circuit.

Individuals of all parties and parts of the trade union law statutes.

Generally speaking, it is common to talk about load current, but there is no such thing as "overload voltage".

Overload...

The terminal voltage rises in the event of an overload...

Overload is when the current in the line is greater than the calculated current or allowable current carrying capacity of the line.

The reasons for the melting or deformation of the air pressure switch may be due to the following:

1.Overload or short circuit: If the load of the wind pressure switch exceeds its rated capacity, or a short circuit fault occurs, the current will increase rapidly, resulting in an increase in the internal temperature of the switch, which will never cause the switch to fuse or deform in extreme cases.

2.Long-term overload: If the wind pressure switch is overloaded for a long time, even if there is no short-circuit fault, it may cause the switch to overheat and deform.

3.The external ambient temperature is too high: If the ambient temperature of the air pressure switch is too high, the internal temperature will also rise, which will cause the switch to blow or deform.

4.Material quality problems: If the quality of the air pressure switch parts is not good, or the use of inferior materials, it may also cause the switch to deform or melt at high temperature or overload.

Therefore, when using the wind pressure switch, it is necessary to ensure its normal load capacity, avoid long-term overload and short circuit, avoid use in high temperature or humid environment, and choose a formal way to purchase products with guaranteed quality in order to better ensure its safety and reliability.

Overload is when the current in the line is greater than the calculated current or allowable current carrying capacity of the line.

Each electrical equipment has its rated power, when the rated power is exceeded, it is called overload, the protection of this state is called overload protection, and the protection against short circuit inside the electrical equipment is called short circuit protection.