Connecting socket and switch in one block

Sockets and switches in one block before the widespread phenomenon occurs in the Soviet buildings were established as a rule in the corridor.

What causes such a concept? From the chart below shows that this Dawla significant wiring savings. To block do not have to pull a four-wire, three is enough!

Tell - a trifle, but now imagine the savings of the vast country, the values ​​are obtained enormous. Yes, the Union was a zealous owner.

Now let's consider the circuit connection.

Transparent connection scheme

When connected, the main wiring to determine power outlet, it is sufficient to use a sampler (cartridge with a bulb and wires).

Where the light comes on in full glow, and will connect the wires to the socket. By the third wire through the jumper we need to connect the switch, according to the rules it should be a phase (but it will be zero due to incorrect installation of wiring).

How to understand, right we wiring or not? See diagram below, if the three wires on one phase turns, your scheme

right and we serve across the bridge phase of the switch.

And if three wires, we found two phases, the installers do not bother and assembled wiring not right. In this case, two specific "rosette" of wires, the switch across the web, we will apply a zero.

Determine the phase connection switch socket block

Have questions, then watch the video:

Other articles on the electrics:

Connecting double switch

How to connect the chandelier

Non-contact detection phase