The outlet in the bathroom must be connected through the RCD. Photo: Jung
one Determine the required number of protection devices
If for a small utility block from one room only an introductory machine on the electrical panel is enough, then a cottage designed for a relatively long and comfortable stay will require much more. In this case, all electrical consumers are divided into groups: lighting, sockets, power devices (boilers, electric heaters, etc.), household equipment (in the garage, basement, various outbuildings and detached objects). Each group needs a separate line protected by a separate machine. If the house is large enough, then it is also advisable to divide the consumers into floors or even into separate rooms.
2 Connect powerful consumers separately from the rest
It is advisable to connect devices that consume high power through a separate line and protect them with a separate machine. If this rule is violated, the overload protection of less powerful consumers may not work at the right time — if the AB is designed for a current that is standard for a heating boiler in a mini-boiler room, then a kettle plugged into a socket, for some reason consuming a current higher than the nominal one, it simply won’t notice. In addition, to power powerful electrical devices, a thicker cable is required, which does not make sense from a technical point of view, and is too expensive from an economic point of view.
3 Calculate the permissible parameters of circuit breakers
RCD. Photo: Eaton
The easiest and most correct way to determine the value of the rated current AB is to look at the current values in the passports of all connected devices and add them up. If for some reason this is difficult to do, then one should proceed from the capacities of energy consumers.
To find out the current strength, it is necessary to divide the power consumption of the load by the voltage of the electrical network. Since power is usually indicated in kilowatts, the value of the current in a single-phase network of 220 V is approximately 5 times less than this value.
four Buy a machine whose characteristics are as close as possible to the calculated ones
Shield_ for circuit breakers. Photo: Eaton
If the type of time-current characteristic is defined correctly, then there is no reason to choose AB with a margin. You should purchase a device designed for current, the value of which is minimally higher than the real one. Based on these considerations, the manufacturer’s equipment should be preferred, offering the user the largest selection of current options. For example, Eaton’s range of circuit breakers includes nine types B and C, ranging from 6A to 63A. This diversity allows you to choose the right set of protection devices without sacrificing the safety of your electrical distribution system.
5 Pay attention to the prices and quality of devices, as well as the reputation of the manufacturer
RCD. Photo: Leroy Merlin
Avoid buying devices in the lower price range: they are of extremely low quality and not only do not effectively protect the power supply system, but can themselves become a source of danger. It is more reliable to choose products of large companies, the quality of which is guaranteed by the manufacturer’s reputation and successful use practices. It is hardly reasonable to make a platform out of your own dacha for experiments with protective equipment of little-known brands or completely nameless.
Photo: Schneider Electric
The editors would like to thank Eaton for their help in preparing the material for this article.