The electrical installation should always be in good condition to avoid short circuits and other dangerous incidents, such as those related to overload. It is crucial to check the wires and cables to make sure that everything is in order. In this article, we will discuss the most important short circuit requirements for protection, we will also look at the impact of short circuit sources. We will also explain the great importance of the type of device on the amount of energy flowing during a short circuit. Understanding these aspects is extremely important in the context of ensuring the protection of cables and wires in emergency situations.
Check cables and wires at the Onninen wholesaler
Short-circuit requirements for protection devices
Electrical installations have their own specifics, operating rules that must always be followed to prevent short circuits and other disruptions. This requires the use of appropriate protection. They are very important in protecting the installation. The protection must effectively detect short circuits and then immediately interrupt the flow of current in the circuits. Thanks to this, the cables and wires will remain intact, without damage. The same can be said about the devices connected to it.
The right selection of wires is therefore invaluable here. It must take into account the maximum expected short-circuit current and the time in which the protection will react. At the same time, the type of protection must be taken into account. We are talking about circuit breakers or fuses, which have different operating characteristics.
They minimize the extremely dangerous phenomenon of long-term current-carrying capacity of wires, which is why the operating time plays a significant role here. The sooner the protection of wires interrupts the flow of current, the better, because the risk of thermal damage to the cables will be eliminated.
This is even more important if the installation cables are high-power. Here, the use of protection should be additionally tested for their resistance to high-current impulses and mechanical resistance. As we can see, in the case of long-term thermal load capacity, there is no joking, so safety issues must be a priority here.
The influence of short-circuit sources on the selection of switches
The principles of conductor selection must always be observed, especially since short-circuit sources, such as power supplies, generators or transformers, significantly affect the selection of switches used in electrical installations. At the same time, remember that the short-circuit current depends not only on the short-circuit power of the source, but also on the network parameters - impedance and distance from the short-circuit location.
The closer the short circuit is to the power source, the automatically increased the value of the short circuit current. This creates a serious challenge for switches. Therefore, in order to guarantee the highest level of protection for the installation, we must remember to use switches taking into account the maximum short circuit currents that can occur in a given circuit.
If we do it incorrectly, the switch may be damaged, but it also may not provide adequate protection during a short circuit, especially with long-term current capacity. The wires and cables may then be seriously damaged. Therefore, the key to selecting wires is to carefully analyze the parameters of the short circuit source, adapting them to the operating conditions of the installation.
But breaking capacity is not everything, because switches must also be resistant to the dynamic and thermal effects of short-circuit currents when the ambient temperature is too high. They must therefore withstand enormous current pulses and mechanical stress.
The influence of the device type on the thermal effect transmitted during a short circuit
When designing an installation, we must always pay attention to the fact that the control cables function well when powering electrical devices, without any unexpected events. The type of protective device is very important here, influencing the amount of thermal energy that is transmitted during a short circuit. Its ability to quickly interrupt the flow of short circuit current without damage determines how much energy will reach the installation. The longer the device waits, the more heat accumulates in the cables. This results in their overheating, but also damage to the insulation, and even melting of metal elements.
The specificity of the device's operation is also of key importance, especially in the context of overcurrent circuit breakers, fuses or differential circuit breakers. This is due to the fact that they differ from each other - in terms of reaction time and method of operation.
If the installation has a large power, as in industry, the most important thing is to use switches with a high breaking capacity. This effectively limits the heat energy that is transmitted. Devices of this type are designed precisely to minimize the effects of a short circuit by immediately interrupting the current. They are also exceptionally resistant to current pulses.
In summary, checking cables and wires for short circuit conditions and requirements is a priority that must always be remembered.