Operating current building standards designed to account for a significant amount of electrical equipment, is equipped with a housing. As a consequence, protect the wearer from possible electric shock is an important requirement. One of the main roles in the organization of an effective barrier plays a residual current device.
We'll show you how to connect the RCD in the apartment without grounding. In the present article we describe in detail the proven assembly of electric circuits with protective gear. Independent domestic masters we find instructions for assembly.
The content of the article:
- The need for an RCD Ground
- How does the protective device without the "land"?
Wiring diagrams RCD without grounding
- The inclusion of the RCD with enhanced functionality
- Nuances connections in private households
- Step by step guide implementation of protection
- Conclusions and useful videos on the topic
The need for an RCD Ground
It is believed that the excellent functioning protective device is achieved only when the availability of the mains with phase conductor contact, the conductor of "zero" and the grounding bus.
In fact, if we consider the work RCD and ground bus operably both devices are designed to perform similar actions - de-energize the circuit in case of leakage of electricity to the housing. The difference is observed only in the circuit principle.
Classical installation of steam, thanks to which is quite effective in blocking and against electric shock, and from the possibility of fire due to short circuit
It follows a logical conclusion: both the circuit solutions are applicable in the practice of housing supply. Moreover, the best option is seen sharing the two circuit solutions.
If the power line is installed RCD ground organization, by and large, it is permissible to exclude. Thus the introduction of the protective device seen reasonable solution for a two-wire power supply, where technically no earthing bar.
The best technical solution for the construction of the electrical circuit wiring residential buildings, where in addition to the protective tripping device activated also grounding rail. Such decisions - a standard for new buildings
Actually, if you carefully examine himself RCD deviceFor it will not be possible to find a terminal, specially designed for the connection of "ground".
This factor proves once again the possibility of including without grounding. However, modern housing projects necessarily presuppose the existence of a ground bus.
How does the protective device without the "land"?
connection option without earth - is a typical case for apartments and private homes of old buildings. Electricity such structures are usually organized without supplying a ground bus. But how correct action can be expected without a RCD inclusion "of the earth"?
Option wiring widespread in relation to project old-style property. The introduction of the old breaker infrastructure devices have to perform in the absence of an earth bus
For example, during operation of electrical breakdown occurred in the housing. In the absence of a ground bus rely on instantaneous actuation RCD installed it is not necessary. If, however, there will touch the man punched the equipment housing, the leakage current will flow to the "ground" through the human body.
It will take some period of time (unit setting the threshold) until the work RCD. During this period (rather short) remains quite acceptable risk of injury from exposure to electrical current. Meanwhile, the RCD would work immediately if there is a ground bus.
Driving electrical wiring without the presence of "ground" where the protection device is connected without additional ground bus, still remains to some extent, the danger for the user. In such situations should be carefully set up on the RCD threshold
In this example it is easy to deduce the expense that connect RCD and machines in the housing panel or a panel of a private house, always together with the connection to the ground bus. Another issue that remains a sufficient number of buildings where there is no opportunity to do so due to lack of "land" in the scheme of the project.
Options for buildings, where electricity is organized without grounding switching device protection by RCD actually looks like the only effective means of protection, which can be applied in such conditions. Therefore, we consider possible schemes applicable to power supply for private housing.
Wiring diagrams RCD without grounding
One of conventional circuit design, which uses the protective device RCD is a variant of the device mounted directly on a power input in the object structure. That is, a residual current device is mounted immediately after the electricity meter.
Traditional connection characteristic for most use cases protective devices on the electrical power lines in the private sector
This approach provides protection to electrical home fully, and hence, the leakage current is monitored every household appliance. From the mains voltage is supplied to the device cable, combines in one housing two phase terminals and two zero (there is also a three-phase devices).
These two pairs of terminals are divided into input and output. One pair of passes phase line through another zero. After completing the layout according to this scheme, sets forth additional machines for each type of load.
Execution of the three-phase device: 1 - terminal supplying a zero bus; 2 - operating current value; 3 - allowable overcurrent value; 4 - the value of the cutoff current; 5 - type device; 6 - phase terminals; 7 - test button; 8 - action indicator; 9 - platoon key
The predominant aspect of this circuitry is to save on electrical equipment. Just installing one device has successfully solved the issue of protection. However, on the other hand, if your home network appear leakage current object, there is a complete blackout of the home.
In some cases, this situation could become unsuitable. To some extent reduced comfort component for property owners. Allow this lack may be using a different circuit solutions - more functional in terms of Multiple Feature Select off.
The inclusion of the RCD with enhanced functionality
Several other schematic, suggesting implementation of the RCD for each separate branch of power, it leads to the protection of more "soft" relative to the blocking power.
Several modified version of the circuit design, where there are two (or more) of protective device. In this case one speaks introductory remaining intermediate: 1, 2 - a zero bus bar terminals
It uses several security devices, depending on the number of branches of electric network of the apartment.
For example, if the two branches exist, the scheme will be as follows layouts:
- Mounting one RCD similarly to the first embodiment - the input.
- Installation of the RCD after subsequent selectively established automata network drops.
- At each branch line protection on the number of consumers.
With this construction and control scheme implemented cutoff voltage with respect to the home private branch wiring. Therefore, the fact the current leakage, as recorded on a separate line, lead to blocking only the network portion in which the load is connected punched. The remaining portions will remain in operation.
For the case of the wiring circuit shown above is a characteristic increase in the dimensions of the control cabinet. Therefore it is not always an option for the device is acceptable in terms of private homes
But more functional solution is not without certain drawbacks. It is clear that with increasing number of devices have to expand switchboard. Increasing the size of the switchboard can also be a problem for the user. In addition to the financial aspect of the choice of application award scheme also seems not entirely successful.
Cost is almost two-fold increase compared with the first embodiment. The truth is if you are already thinking about an effective full-featured protection, saving is not recommended in this case.
Nuances connections in private households
Private buildings differ from the apartments of public housing is essential. The first use of the equipment that is never used in the apartments. For example, the traditional equipment of the private sector are the electric heating system or electrical heating bath module.
Often requires the inclusion of the safety interlock device on circuits powerful appliances. In this case, when the private sector is involved residential electric boiler. For such equipment is mandatory tire earthen
For any of these systems is absolutely necessary to put the safety shutdown, as it is not just household appliances, but rather a powerful technological equipment. Here, the RCD is not just protection against leakage current on the body, but also serves as a fire-prevention safety device.
In relation to such projects often uses circuitry to "TT" system that provides relative safety in cases of leakage currents in the equipment housing.
Scheme "TT" for electrical networks, which use hollow earthed neutral: 1 - a transformer with a grounded neutral bus; 2 - limiting resistor; 3 - a disconnecting device; 4, 5 - consumer load section
Addition of such a circuit device Lock enhances the degree of reliability. However, the system "CT" requires a ground bus.
Step by step guide implementation of protection
For complete information regarding the connection devices ensuring protective cutoff, consider a stepwise process creating a communication circuit with the introduction of the protection device:
- bring to switchboard power cable from a centralized interface input energy into the house.
- Inside the panel mount circuit breaker (this device is pre-calculated to total cutoff of load network).
- Mount electric meter in a convenient location and connect the machine output to the input terminals of the meter.
- Set inside the RCD shield and connect the input of the device (upper terminals) to output terminals Electric.
- At the output (phase) terminal of phase conductor RCD connect home wiring.
- On the output (zero) RCD clamp connect the neutral conductor home wiring.
- Connect the main cable to the input terminals of automatic switch.
Performing selected operations should take into account some of the nuances. For example, it is necessary to follow the rule consistent with the circuit breaker protecting the cutoff device.
If it does not provide for the introduction of the machine network, it is imperative to put in place the machine fuses.
Fusible links that can be used for protection of electrical circuits for short circuit currents. Fusible elements can sometimes be used to protect, replacing the function of circuit breakers
As a rule, the rated current value of the security module is recommended to take a few more than the current value of the circuit breaker. In some cases, this option may be chosen equal to the parameters of the machine.
Performing work on the integration of the supply protection device, it is recommended to check all available circuits for possible defects. After installation of the device is required to test the effectiveness of the cut-off. For this operation, there is a special test button on the front panel.
Testing correct operation of protection keys. After installation and connection of the RCD should take advantage of these elements of the device for checking the protective function
When installing all the work on the connection must be carried out carefully.
Supply network lines should be carried out in strict accordance with the icons present on the device. That is, the phase is connected to the "phase" and, accordingly, zero is connected to "zero". From change of places "terms" there is a high risk of exit of the protective device down.
Conclusions and useful videos on the topic
This article concludes a video clip about the instruments used as security systems, electrical networks, equipment and users of apartments and private homes. Review material with all the subtleties of use, which will certainly come in handy for practice.
Connect the RCD without grounding in modern apartments the sample is not only recommended, but also prohibited. If you need to install the equipment in a switchboard, be sure to contact the webmaster serving the house. All work concerning obschekvartirnogo shield filling a qualified technician.
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