What to do if in the socket two phases?
There is also such situation when in the socket two phases and are not present light. Somehow my friend calls me and asks to approach to help to deal with electricity at his place and just in case that I captured the indicator. The problem was in the following: it inserts the indicator into the socket, and that shows that in both entrances in the phase socket. I give it the indicator and it shows most too – two phases. Means, and my indicator "lies"? We with it walked on all rooms, povytaskivat all electric devices from sockets and checked that all switches were in the family way "is switched off". And after that checked sockets again - the second phase as happened. I explained to him that in the apartment there are no 0 years, and the "second" phase came to other end of the socket via some switched-on electric device or the bulb.
It occurs because all zero ends are tied among themselves by the scheme of the electrical wiring, and somewhere, through the switched-on switch, the phase through filament of the bulb connected to the zero wire, and it turns out that in the socket two phases. If to try to measure it with (present) 0, then tension on it will be not 220 V, and it is less at the expense of resistance of filament of one or several bulbs. And business was in the fused stopper. Replaced the stopper - and everything rose on the places. On the scheme it is well visible how the phase comes on 0. Generally, when in the "two phases" socket - means there is no 0. Still the small addition - "the second phase" at such moment – is dangerous and to handle it as with 0 it is impossible!
I will give one more example. The operator from one my object tells me that one electric motor is strongly heated. Arrived, looked, listened - everything normally, but temperature big - the hand long not to hold. The indicator fast checked - all 3 phases on site. Beru pincers, I measure current - as a result one phase loading - 0. I switch-off the electric motor, again I check, one insert (safety lock) – fused, and the operating time of the elektrodigatel - the phase "was rung, through the stator winding. Replaced the insert and everything went. It is the everyday occurence from life of the electrician and it would seem what here unusual and the matter is that the lack of the phase, did not affect operation of the engine at all, for example can sometimes howl or hoot slightly, all this was not. And one more moment - it is possible to check safety locks at the working electric motor the control lamp or the voltmeter - the result will be one - the phase "incomplete", that is it in general is absent.
It is extremely dangerous to make nulling of electric equipment! There can be such situation when electric equipment grounded by the nulling method turns out energized, in the absence of 0.