What Is Overload? What Is Overcurrent? Did You Know~

Overcurrent Protection:

We mentioned earlier that overcurrent is a state. When overcurrent occurs, it is often smaller than short-circuit current, and it is within six times.

Usually, in electrical circuits, the probability of short circuit is much smaller than that of an overcurrent, especially when the motor is frequently started and reversed.

What needs to be mentioned here is that when there is an overcurrent in the line, if the current value can be restored to normal before reaching the maximum temperature rise, then the electrical components can still operate normally.

But there is one point, the overcurrent here may cause the inrush current to damage the motor. At this time, the instantaneous electromagnetic torque will damage the mechanical transmission components. Therefore, it is very necessary to cut off the power supply in time.

Overcurrent protection uses an overcurrent protection relay, which is installed in the protected circuit. When the current reaches a set value, the relay will act. Its normally closed contact is connected in series in the branch where the contactor coil is located so that the contactor coil is powered off, and then the main contact of the contactor in the main circuit is disconnected, so that the motor power is cut off in time.

Short circuit protection:

Many novices do not know that in the power system if the electrical equipment in the line or the insulation of its wiring is damaged, there may be wiring errors or load short circuits. Then, when such a situation occurs, the equipment will have a short circuit failure.

When a short-circuit fault occurs, at this time, the instantaneous current of the appliance is not only a little higher than the rated current but exceeds dozens of times.

The consequence of this may be that the electrical equipment is damaged due to the strong electric power in the electrical line, and an arc is generated at the same time, and the serious consequence will lead to the occurrence of a fire.

Therefore, we need to take some measures to avoid the harm caused by short-circuit faults, which is called short-circuit protection. Here we need to quickly cut off the power supply after a fault occurs. The method often used here is to install a fuse or a low-voltage circuit breaker in the electrical circuit.