How to protect the house from surge surges?
Hello. I have the task of comprehensive protection against pulsed currents of a private house, which is connected via an overhead line of 3 phase voltage. With a grounding system made according to the TT scheme with an individual grounding circuit, and with a common RCD installed for all consumers.
The street pole of the overhead line is the final one along the street; a shield with the following type of electricity metering device NP73E.2-12-1 is installed on the pole. According to the description, it says there is a protective shutdown, but it is not specified how and under what conditions. The distance of the overhead line from the pillar to the inner shield is about 15 meters.
QUESTION: what is the best way to implement protection? I am considering this option, please comment on which of your equipment I can use, and whether such an application will be true:
- Install an SPD of class 1, or an SPD of 1 and 2 classes on a pole and ground directly near the pole. Which is better before or after the counter? In which version connect 3 + 1 or 4 + 0. Bit type or varistor?
- In the shield in the house put the overvoltage relay UZM-50 (51) or similar, to control both high and low voltage, with the possibility
automatically turn back on.
2 QUESTION: Protecting the telephone line. The house has an AIR-UNDERGROUND two-wire copper telephone line for telephone communications and the Internet using VDSL technology. In total, about 15-20 m of cable goes through the air. What protection devices should be used in this case? Thank you very much in advance.
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Hello! On the shield. Most likely, protective shutdown is understood as an automaton, in the best case an RCD or Dif.
By SPD. To a greater extent, varistor devices are used for these purposes. Bit is more in KTP and RU.
You somehow implicitly wrote inclusion schemes, send a photo or drawing. In any case, it must suppress the high voltage pulse to the ground or between phases.
Before or after the meter does not really matter, but if they let you install them before the meter, then in this case they will protect the meter itself. But it’s not a fact that the energy supply, homeowners association or whoever supplies you there and who makes the connection will let you do it without unnecessary nerves and waste of time.
To protect the telephone line. Do you want to protect her from a thunderstorm? As far as I know, varistors also use to protect data lines. You can look at the market for galvanic or optical isolation.
It will not be superfluous to install a relay in the house’s shield, but it will protect not from bursts, but from simple drops and rises, for example, when the phases are out of phase.