the best of those or other reasons and circumstances in power voltage may appear unfavorable for home appliances.
It can be: open "zero" in the three-phase circuit, overloaded transformer substation, power lines obsolete.As a consequence, instead of the power of your 220 (plus - minus 10%), you may receive a higher voltage (380 V for example) or low (eg 170 wills).In such adverse conditions, household appliances, or "refused" to work or crashes.
prevent the negative impact of these factors on the appliances can be by setting the voltage or voltage relay.
voltage regulator - the appliance, which stabilizes the input voltage of the power supply (high or too low), and already gives our consumer network, regulated voltage (output voltage range depends on the model of the stabilizer), but in any case within the tolerance.Appliances connected to the stabilizer will work stably and reliably, regardless of the input voltage.It is used stabilizer is usually in suburban homes, father-in regional areas.Input
voltage relay - the appliance, which will disable the entire electrical engineering (which is connected to it) in the case of elevated or underestimated the power supply network.Such devices are usually placed in apartments.Relays are single-phase (single-phase networks) and three-phase (for three-phase networks).To select a single-phase power switch, you must calculate the power of all the appliances that will be connected through this relay.When installing three-phase relay takes into account not only the power of all electric appliances, and of the distribution of the phases.There is also a three-phase relay contactor is needed, which performs the function of communication, as in the three-phase relay is available.The input voltage range and the response time is programmed individually, at any time and very simply.
Mounting and installation of the stabilizer and voltage relays, must by a qualified electrician, with at least fourth group tolerance.