How to select the RCD for houses and apartments ?

importance of the event

If you select the wrong RCD model that is wrong with its characteristics, it is fraught with the following consequences:

1. Automation will operate during a false alarm, becauseminor leakage of electricity is always present in the wiring, especially if it is old (in a wooden house in the country).
2. too high RCD power characteristics, which do you prefer, will not be triggered during a dangerous situation, whereby it is possible to receive an electric shock.
3. device will not be able to function when connecting aluminum conductors your home wiring, because most of today's models are designed only for connection of copper conductors.

To avoid these errors, you must first understand the characteristics of the differential switch, then move on to his choice.

main characteristics of the device

So, among the most important technical characteristics that need to be lean when selecting an RCD for apartments and private houses are isolated:

• Rated voltage: 220 V (single-phase) or 380 V (three-phase).
• Number of poles: bipolar (if 1 phase) and four-pole (if 3 phases).
• rated load current can be 16A, 20A, 25A, 32A, 40A, 63A, 80A, 100A.
• rated residual current (leakage) of 6 mA, 10 mA, 30 mA, 100 mA, 300 mA, 500 mA.
• Rated conditional short-circuit current - ranges from 3 kA to 15 kA.In simple words, this value indicates the reliability of the RCD and its stability in the event of faults.The front panel of the value displayed in the rectangle in amperes or after «Inc» symbol.
• Switching capacity (symbol «Im») - is the maximum value at which the product is able to properly react.It should not be less than 10 rated load values, or at least 500 A (modern products have switching capacity from 1000 to 1500 A).
• working principle: AC - operation with AC, A - AC + DC pulsing, B - AC +, S - there is a time delay before firing, G - is also present an excerpt, but her time is less.
• design electronic (mains powered) or electromechanical (no power).

existing specifications we provide to you now consider in detail how they should be taken into account to select the RCD in power is correct (in this case, amperage), current leakage, and other parameters.

recommend reviewing a selection of video lessons in which a procedure for calculating the RCD discussed in detail, as well as a strategy for choosing an appropriate model tables Example:

criteria for the correct choice

Rated

The first thing you need to pay attention - to a calculated current device.To correctly select the RCD current, you must initially decide on the purposes for which the product will be installed.If you want to protect a single network element, for example, a washing machine, a system of electric floor heating or water heater (boiler), the value can not be higher than 16 A. For all the wiring in an apartment unit should be placed not less than 30 A.To find the right value, you must first calculate the load of all the connected appliances and building on the amount received to choose the most suitable model RCD.In the case of modern technology manufacturers usually indicate the nominal current load, so the calculations should not be difficult.

Differential current

We have reviewed all the existing values, which range from 10 to 500 mA, and now understand, better to choose a RCD on the amperage in certain situations.Protect against electric shock, ensure the setting of 6 to 100 mA.At the same time, more than 30 mA leakage will be felt by the body.That is why the child and the bathroom is better to use the model to 10 mA, and for the protection of outlets and fixtures 30 mA.

There should also be noted that each appliance has a natural leakage current, which is indicated in the attached data sheet.When selecting an RCD leakage current is required to observe the following rule: the sum of the natural leakage must not exceed the nominal value of the security appliance for more than 30% (1/3).Otherwise, false positives will occur, from which a lot of trouble.

Product type

So, in simple words explain the purpose of each type of RCD:

1. AU - mainly used to protect the electrical appliances in the home when used as single-phase and three-phase network.Household appliances with pulsed current, for example, a washing machine, to protect such a product can not.
2. A - used just for individual protection of washing machines in the apartments and private homes.
3. B - mainly used in the production, so choose this type does not make sense for the home.
4. S - as we have said, is not off immediately when a leak is detected, and in particular the setting time.As a rule, used to prevent fire and is connected to the opening panel, serving all of the wiring (and therefore setting of at least 100 mA is selected on the leakage current).
5. G - mostly connected to a separate appliance for monitoring and timely fire protection.Unlike «S» type is minimal dwell time.

design

here especially to talk about, electrons have a more complex working principle and function only in the presence of the power supply (or external power supply).A more reliable and durable - electromechanical, so it is best to select electromechanical RCD for apartments and houses, besides the cost will be much lower.

Manufacturer

And the last, least important criterion for selecting an RCD - according to the manufacturer.To date, the following companies are the best in the production of these products:

• Legrand;
• ABB;
• AEG;
• Schneider electric;
• Siemens;
• DEKraft.

Among the low-end models is the high quality of the companies Austro-RCD and DEC.

recommend to give preference to more expensive products, but if the budget does not allow a fine job with the protection of domestic manufacturers.In any case, before buying advise you to visit the forums on the electrics and review customer feedback on the chosen model!As you probably know all the advantages and disadvantages of the product and determine exactly how best to choose the RCD.

Summing up

Here we provide guidance on the selection of protective devices, and now I would like to summarize and highlight the models that are used most often:

Detached house (or cottage) .On entering a residual current device rated at no less than 100 mA to respond to the leak, such as S and the rated current of 63 A. To date, we used three-phase network, so VDT should be four-pole.In separate groups: outlets, fixtures, etc.recommended to install one of RCD type A (or AC) at 30 mA and the nominal current load according to calculations - 16/25 / 32A.

Apartment .Everything is easier.Introductory board - device 32A, 30mA, type A / AC, usually double-pole (if not carried out the replacement of wiring in an apartment on a new one).For the washing machine or the bathroom, you can choose another RCD 16A separately.

That's all I wanted to tell you about this issue.We hope that you now know how to choose the RCD for apartments and houses for power, leakage current, the manufacturer!
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