How to choose the RCD for the house and apartment?

importance of the event

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

1. Automation will be triggered during a false alarm, becauseminor leaks of electricity are always present in the wiring, especially if it is old( in a wooden house in the country).
2. Too high RCD power characteristics that you give preference to will not work during a hazardous situation, as a result of which you can get an electric shock.
3. The device will not be able to function when connecting the aluminum conductors of your home wiring, since most modern models are designed only for connecting copper conductors.

In order to prevent these errors, you first need to understand the characteristics of the differential switch, and then proceed to its selection.

The main characteristics of the device

So, among the most important technical characteristics that you need to rely on when choosing an RCD for an apartment and a private house, distinguish:

• Nominal network voltage: 220 V( single-phase) or 380 V( three-phase).
• Number of poles: bipolar( if 1 phase) and four-pole( if 3 phases).
• The rated load current can be 16A, 20A, 25A, 32A, 40A, 63A, 80A, 100A.
• Nominal tripping differential current( leakage) 6 mA, 10 mA, 30 mA, 100 mA, 300 mA, 500 mA.
• Nominal conditional short-circuit current - varies from 3 kA to 15 kA.In simple words, this value shows the reliability of the RCD and its stability in the event of a short-circuit. On the front panel, the value is displayed in the rectangle in amperes, or after the "Inc" symbol.
• Switching capacity( designation "Im") - represents the maximum value at which the product is able to react normally. Should not be less than 10 values ​​of the rated load, or not less than 500 A( modern products have a switching capacity of 1000 to 1500 A).
• Principle of operation: AC - actuation with alternating current, A - variable + constant pulsating, B - constant + variable, S - delay time before activation, G - shutter speed is also present, but its time is shorter.
• Construction: electronic( works on the network) or electromechanical( does not require power).

We have provided the existing characteristics, now we will consider in detail how to take them into account in order to choose the correct RCD for power( in this case amperage), the leakage current and other parameters.

We advise you to look at a selection of video lessons that discuss in more detail the procedure for calculating the RCD, as well as the strategy for selecting the appropriate model using the example tables:

Criteria for correct selection

Rated current

The first thing you need to pay attention to is the current calculated by the device. In order to correctly select an RCD with respect to the current, you must first determine the purpose for which the product will be installed. If you want to protect a separate network element, for example, a washing machine, an electric floor heating system or a water heater( boiler), the value can be no higher than 16 A. For all electrical wiring in the apartment you need to put the unit no less than 30 A.To correctly select the value, you first need to calculate the load from all connected electrical appliances and based on the amount received select the most suitable model of the RCD.On the body of modern technology, manufacturers usually indicate the rated current load, so the calculations should not be difficult.

Differential current

We have considered all the existing values, which range from 10 to 500 mA, now we will figure out which RCD is better to choose for amperage in certain situations. Protecting a person from electric shock is provided by settings from 6 to 100 mA.At the same time, leaks above 30 mA will be felt by the human body. That's why in the nursery and bathroom it is better to use the model for 10 mA, and to protect the sockets and lamps 30 mA.

It should also be noted that each electrical appliance has a natural leakage current, which is indicated in the attached technical data sheet. When selecting an RCD for leakage current, be sure to consider the following rule: the sum of natural leaks should not exceed the protective device rating by more than 30%( 1/3).Otherwise, there will be false triggers, which are a lot of trouble.

Product Type

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

1. AS - mainly used to protect electrical appliances at home using both single-phase and three-phase networks. Household appliances with a pulsating current, for example, a washing machine, can not protect such a product.
2. And - is used just for the separate protection of washing machines in apartments and private houses.
3. B - mainly used in production, so choosing this type for the house does not make sense.
4. S - as we have already said, the trip does not occur immediately when a leak is detected, but through a certain time setpoint. As a rule, it is used to prevent a fire and is connected to the input board, servicing all electrical wiring( therefore, the set point for the leakage current is selected at least 100 mA).
5. G - basically connects to a separate electrical appliance for monitoring and timely fire protection. In contrast to type "S" has a slower aging time.

Construction

There is nothing special to say here, electronic systems have a more complex operating principle and function only if there is a power source( external or mains).More reliable and durable - electromechanical, so it is better to choose an electromechanical UZO for an apartment and a house, besides the cost will be an order of magnitude lower.

Manufacturer

Well, the last, no less important criterion for choosing an RCD - according to the manufacturer. To date, the best companies in the production of these products are the following companies:

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

Among the budget models the highest quality among the companies Austro-UZO and DEK.

We recommend to give preference to more expensive products, but if the budget does not allow, domestic manufacturers will be able to cope well with the protection. In any case, before buying, we advise you to visit the forums on electricians and get acquainted with the customers' opinions about the chosen model! So you will surely learn all the advantages and disadvantages of the product and determine exactly which RCD is better to choose.

Summing up

Here we have provided recommendations for choosing a residual current device, now I would like to summarize and highlight the models that are used most often:

Detached house( or cottage) .At the input, a protective shutdown device with a rating of at least 100 mA for leakage response, type S and rated current 63 A. Today, a three-phase network is used, so the VDT must be four-pole. On separate groups: sockets, fixtures, etc.it is recommended to install one type of RCD type A( or AC) at 30 mA and a rated current load according to the calculations - 16 /25/ 32A.

Apartment .Everything is simpler here. The input board is a 32A, 30 mA device, type A / AC, usually two-pole( unless the electrical wiring in the apartment has been replaced with a new one).For a washing machine or a bathroom, you can choose one more RCD separately for 16A.

This is all I wanted to tell you about this issue. We hope that now you know how to properly choose the RCD for the apartment and the house in terms of capacity, leakage current, the manufacturer!
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