The connection of sockets with a loop is often used when installing electrical wiring in an apartment. This is a fairly common connection method; in essence, it is a backbone connection of consumers.
Connection methods
There are currently two main schemes arrangement of electrical wiring in the apartment:
- Radial connection (sometimes called "star" connection, which should not be confused with the circuit used in three-phase circuits). This technical solution is widely used in apartments and private houses. Its main advantages are simplicity and reliability. The main disadvantage is the high consumption of expensive cable.
- Ring diagram. It is practically not used in our country, but it is widespread in some regions of Western Europe. The meaning of such a connection is that the electrical circuit supplying the load is closed in a ring. This achieves the possibility of supplying consumers simultaneously from two sides. The ring scheme significantly increases the efficiency of electrical wiring compared to the traditional radial connection and at the same time is more reliable in relation to the main one.
Wiring diagram
In case of radial connection of each outlet a separate line is allocated, going directly to the junction box. Naturally, the reliability of such a scheme is the highest of all non-redundant connections. In order to reduce the consumption of electrical cable required for the installation of electrical wiring in a radial pattern, looping of sockets is often used.
Loop connection can only be used in cases where the total power of consumers, as well as their technical characteristics and operating conditions allow it.
In general, the scheme for connecting a group of sockets with a loop looks like this:
Since this circuit uses socket terminals as places for connecting wires, such a connection has some properties of a series electrical circuit. Namely:
- If the wire burns out at the terminal of one of the devices (the vast majority of breaks occur in such places), all the devices following it are inoperative.
- Connecting each of the consumers causes a significant increase in current in the wires connecting the sockets to the electrical box.
Thus, it is advisable to use the connection of sockets with a loop in cases where the total power of consumers does not exceed the maximum allowable power of the cable supplying the group of sockets.
Features of mounting a group of sockets with a loop:
- According to the requirements of the PUE, the PE conductor should not have breaks. To connect it to the terminals of the electrical installation, separate branches must be used. Incorrect connection of the ground conductor can lead to the fact that if it breaks at one of the outlets, all other devices will also be ungrounded. Since it is impossible to determine the quality of grounding without special measurements or visual inspection of the integrity of the PE conductor, in this case it is not possible to achieve the required level of electrical safety.
- To protect consumers fed from a group of outlets, a circuit breaker 16 A. If the total power of the supplied electrical installations exceeds 3 kW, then a separate line must be laid for each device.
Installation of branches in the socket
In order to fully comply with the requirements of the PUE and at the same time not incur too high costs for laying a separate PE conductor to each outlet, you can make branches directly in the socket. For this, special terminal blocks or crimp sleeves can be used.
The main advantage of terminal blocks is the absence of the need to use special tools for their installation. Such products are installed very quickly and easily. In addition, each of them can be easily dismantled for repair or maintenance of the junctions of the wiring elements.
In turn, the advantages of crimp sleeves include a higher quality of the electrical connection, as well as their low price.
When using terminal blocks or crimp sleeves, it is necessary to proceed very carefully, since it will be necessary to compactly arrange all the resulting connections in the socket. Some experts recommend not being limited to making a branch for the ground wire, but connecting the phase and zero to the socket contacts in the same way.
Phase and neutral wires can be connected directly to the socket contacts. The quality of such a connection is largely determined by the type of contact. Standard bolt clamps are often not able to provide sufficient reliability for connecting two wires inserted into them at once. Therefore, for devices intended for daisy chain connection, terminal blocks must be used. Another option is to use quality devices equipped with several clamps for each terminal.
The procedure for the installation of a stub connection
- Preparation of installation sites for socket boxes and wall chasing for cable laying between sockets.
- Laying a cable from the junction box to the first socket, from the first to the second, and so on according to the number of sockets in the loop.
- Installation of socket boxes.
- Preparation of branches for connecting a PE conductor, and, if necessary, a neutral and phase wire.
- Installation of branches and laying them in the socket.
- Connecting the neutral, phase and ground conductors to the corresponding terminals of the device.
- Fixing the working part of the product in the mounting box.
- Installing the outlet cover.
Thus, the daisy-chaining of sockets can significantly save on the length of electrical cables. In addition, it makes it possible to significantly reduce the amount of construction work on laying electrical wiring. Such a technical solution may be ideal when it becomes necessary to add one or two outlets in the room without major repairs.
