Build Daily


August 12, 2017 18:08

How to select the RCD to be installed in the apartment


  • 1 application of circuit breakers in the apartment
    • 1.1 device home breaker
    • 1.2 consider the principle of the RCD without grounding
  • 2 What type of RCD is applicable in homes andapartments
    • 2.1 How do I check on the efficiency of the RCD

for those who are worried about defending their home against electric shock, the question arises: how to select the RCD for an apartment or house?
Due to the abundance of these devices for the classification and type, you can buy it is not what you need, and all the efforts to protect the family will be in vain.
This article will help you in the selection of this device.

Application apartment breakers

RCD at the house or apartment is necessary to protect against the negative impact of electric current on the human body, which directly touched the live parts of electrical equipment or a body under voltage, inDue to the failure of its individual parts.
Also, this device is used to protect against fire wiring in aging or damaged insulation of wires and cables.

Note that the RCD is turned off when a ground leakage, but if you take up the work phase and zero, it will treat it as a load connection and disconnection does not happen, which is fraught with tragedy.

protection device home

machine The device RCD includes: a toroidal core made of ferrite a certain brand, the two primary coils (single-phase RCD), made of copper wire cross-section of not less than the rated load current, a secondarya coil of a thin wire and with a large number of turns.
actuator is designed to turn off the power contacts in the event of an earth leakage, test key resistance required for verification of RCD on the performance, when pressed, which are changing the currents in the phase and neutral coil, which leads to triggering off mechanism, a current amplifier (in RCDs with electronic control), and the device body.

consider the principle of the RCD without grounding

By and large, the grounding conductor to work it is not necessary, since the phase of use and working zero.These two conductors pass through a kind of current transformer control coil.
assume the load of 10 amps.According to the phase conductors to the load current will flow so strong.And passing through the load, it is back on the neutral conductor with the same parameters.Once a person has touched the body of the boiler, for example, which went bankrupt PETN and potential appeared on the body, a portion of the current through the body starts to go into the ground and the current difference in the phase and neutral conductor changes.These changes scanty captures and transmits the control coil of the relay, which in turn drives the mechanism to a trip line and disconnects from the mains.

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What type of RCD is applicable in homes and apartments

When asked what type of RCD put on entering the apartment, the answer is simple - the machine withdifferential protection (type AC-AC and type A for pulsating and alternating currents), and an electromechanical release device that does not require an additional power supply.Buy the device must be of good quality, such as the German company ABB.She has earned a lot of popularity for its quality electrical products and reasonable price.This will ensure the reliability and security.
Such machines in addition to tripping earth leakage, provide protection against short-circuit and over-current consumption.
Calculation of differential circuit breaker.
first step is to calculate what the maximum current can consume electrical equipment in the house or apartment.We believe their total power in watts, which is indicated on the label of the instrument, and then divide the output voltage on the network and obtain the current in amperes.
example: total power of 4000 watts priborov-.Divide by 220 and get 18 amperes.Therefore, the machine must be at least 20 amps.
As for the leakage current, then to the normal apartment is suitable for 30 milliamps.These often occur in electrical and stores.
If there is a shower and a particularly damp areas, it is advisable to make a separate power line and install for better security Emergency circuit breakers at 10 milliamps.
For larger residences, where all the wiring can total length of up to a kilometer or more, RCD at the house put a face value of 100 mA and higher, as if such a line length is unavoidable leakage, which may lead to false tripping RCDs.Next you need to connect the RCD in the panel on each group separately with nominal 30 mA leakage current.This will ensure the protection of a certain area.

Nominal current induction machines working in tandem with the RCD

Current denomination machines that are connected to the RCD in the panel as the input, and in groups, to be lower than with automatic differential protection.It is necessary that the load on the network fell on conventional circuit breakers, as they cost ten times cheaper machines with RCD.Also, higher currents can cause incorrect work of the RCD mechanism.
errors during installation.
common mistake when connecting ouzo in the apartment, it is that a grounded outlet neutral without passing through the RCD and is used as a grounding, is connected to the zero Clem in the socket.This leads to shut down the machine with a differential protection when you try to turn anything into this socket.If this happens, reverse the neutral wire to a grounding outlet Clem knocks.
should also be properly connected the wires at the entrance to the unit.Phase - a contact & lt; & lt; L & gt; & gt ;, and the zero - at & lt; & lt;N & gt; & gt ;.This will ensure correct operation of the device.

How do I check on the efficiency of the RCD

As already mentioned, this button is provided & lt; & lt; test & gt; & gt ;.
But her work does not guarantee complete protection.In order to fully verify performance of the device, then once a month on the ground to simulate a leak.This can be done very simply.Mark bipolar voltage pointer type LED & lt; & lt; contact & gt; & gt ;, which define the socket phase, one contact insert pointer in phase and the other touch the grounded conductor, such as a radiator or a metal water pipe.Also, if in the country or in a private house just stick a pin in the ground and touch its second end pointer.
During normal operation, the RCD should work as LED leakage current is generally greater than 30 milliamps.In the extreme case, you can use a cartridge with a bulb at 220 volts.Also, one end of the cartridge to connect the phase, another on the ground.The result should be the same.If the RCD does not work, it's time to change it.

Important!Connection Errors video ouzo