Most often, such an unpleasant phenomenon as 380V (overvoltage in the network) occurs in spring and autumn, when the heating is not yet included, and to bask such as you have
The second common reason of such phenomenon - an attempt by a neighbor to self paszamant in the flap entrance or overcurrent (true, often the condition of the wiring inside the panel - have no, what is there to be surprised )
Why are these 380V, indeed, in our houses and apartments 220V? some basic theory
Is there such thing as a "phase" and "zero". They are in any of our outlet. Remember that our screwdriver now with a light bulb (control print )?
If you put in one hole of the socket, the bulb will light up (this phase), and no (that's zero). Current flows from the phase through the load (everything that is included in the socket) and exits through the zero
Voltage between phase and zero are called phase and it is 220V (us). To the house usually fail three phase and the zero (four wires) for smoother distribution of load (in addition, some engines, welding and other devices for supply is not 220V, they need all three phases or 380V)
The voltage between any two wires with the "phases" referred to as linear and it is 380
What does that mean? And the fact that, on one platform, You and Your neighbors connected to different phases, but common to all of You - "zero"
If you do not go into the physics of the process, let's just say: 380V or overvoltage occurs when "zero" otgorit in switchboard or at the substation (due to congestion), in this case, instead of phase (220V) we have a linear (380V) voltage.
Our technique, of course, is not designed for 380V: light bulbs begin to Shine with a white light and burn in his eyes, the sound of the motor of the refrigerator like it is now on the rise go from the TV, the DVD receiver appears white smoke with a disgusting smell and all goes out
How to protect your equipment from similar, see useful tips, and now - about what you need to do, since it's already happened
First of all, as soon as possible to power off the apartment (the house), disconnect tube (machines) and don't forget to pull all the plugs from sockets. Why they have not worked and do not protect equipment from Delta? and it is not their function, they work not overload voltage and over current (ie, only when short slyvania has already happened, read more here: why are fuses)
Make the inclusion of machines only when you are sure that the problem (380) has already been fixed, otherwise it burns (or burns out) again
do Not include into the network the equipment and devices from which the smoke went, and not to delay the repair, otherwise hot acid ejected with a powerful surge inside the instrument may corrode parts and so disfigure fee that will not find it.
It so happens that, despite the smoke, the technique still works even in this case suggest to immediately apply to the master , otherwise the acid, spilled on Board with the details and got into every crevice and hole with rations - will do the trick and this, of course, will ultimately affect the cost of the repair and your wallet
Also, do not forget that acid has a conductivity (through it can pass current, and he will do it by adding the number of burnt parts, and if located near the processor? don't risk, you don't need )