What is an RCD and how is it used?
The main purpose of the RCD (residual current device) is to compare the current that entered the apartment with the current that left the apartment.
If the currents are different, the RCD immediately cuts off the voltage. The RCD must be installed at the time of network installation.
What are the benefits of using an RCD?
This device will help you if there is a breakdown in the insulation of wires in any electrical appliances. For example, if the insulation of the phase wire is damaged in the washing machine and the current goes to the box, then the RCD will turn off the electricity, because the current that went to the apartment on the phase wire did not return to the RCD.
With careless handling of electrical wiring, an RCD can save lives. For example, if, while drilling a wall, you lean with your bare feet on the battery and get into the phase wire, then the electric current passing through: the body of the drill - arm - chest - leg - battery will cause cardiac paralysis or respiratory arrest . If there is an RCD in the house, the voltage will be turned off very quickly and nothing terrible will happen.An RCD can also protect against careless handling of electrical appliances.
But you need to understand that the RCD has no intelligence and therefore will not determine what exactly is included in the electrical circuit. If there is no leakage current, the device will not turn off the electricity. However, an RCD greatly increases safety, since most often an electric shock is associated with a leakage current, and it is this RCD that is easily recognized. The risk of life-threatening situations without current leakage is very low.
Just one device is enough for the whole apartment to ensure reliable protection against electric shock. It is good, in case of problems with electrical wiring or electrical appliances, to turn off only the relevant line and not to turn off the whole room. But, unfortunately, more than one RCD can be installed only in a separate panel located in the apartment. But there is hardly any room in the dashboard of the site.
When an RCD is used for a single line, then in order for the electric current to flow to the consumer, you must have a built-in maximum current limiter. And if you put an ordinary RCD, then there is a high risk that it will fail in the event of a short circuit.
When does it not make sense to install an RCD?
If the house has old wiring, then the ability of the RCD to detect current leakage will only bring problems, as it will begin to work completely unpredictably. In this situation, it is better not to install an RCD in the power circuit, but simply to use sockets with a built-in RCD.