Internal Circuits and Electrical Installations in Residential Buildings
INTERNAL CIRCUITS
Protector Overview
Private protection circuits are implemented in accordance with the ITC-BT-17 and contain at least:
- An automatic cut-off switch with manual omnipolar of minimum rated current of 25 A and protection devices against overloads and short circuits. The power switch is independent of the switch for power control (PCI) and cannot be replaced by it.
- One or more switches that ensure protection against indirect contact of all circuits with a differential-residual intensity of 30 mA and maximum rated current or higher than the general switch. When using switches in series, it will ensure that all circuits are protected against differential-residual intensity of 30 mA maximum, being able to install other differentials of intensity greater than 30 mA in series, and who fulfill the above.
For residential installations fed different networks to type TT, which eventually might be authorized, protection against indirect contact is achieved as indicated in paragraph 4.1 of the ITC-BT-24.
- Surge protection devices, if necessary, under the ITC-BT-23.
Provision for Automation of System Installations, Technical Management, and Energy Security
In the case of facilities automation systems, technical management of energy and security, developed in ITC-BT-51, the power to control devices and centralized control of electronic systems will be done through a circuit breaker omnipolar cutting with protection device against overloads and short circuits that may be located upstream of any switches, provided that their diet is made through a source of SELV or PELV according ITC-BT-36.
Derivations
The independent circuit types shall be as set out below and will be protected each by a court omnipolar breaker with manual and protective devices against overloads and short circuits with a rated current according to the application and indicated in paragraph 3.
1. Basic Electrification
Independent circuits:
- C1 internal distribution circuit, intended for the lighting points.
- C2 circuit internal distribution outlets for general use and refrigerator.
- C3 internal distribution circuit, designed to feed the stove and oven.
- C4 internal distribution circuit, for feeding the washing machine, dishwasher and electric boiler.
- C5 internal distribution circuit, designed to feed outlets bathrooms, as well as auxiliary bases kitchen room.
Determinations in Number of Circuits, Section of Drivers, and Voltage Drop
Table 1 lists the minimum circuit provided with electrical characteristics.
The circuit section indicated minimum is calculated for a limited number of points of use. Increase the number of points of use will require the installation of additional circuits involved.
Each fixture or circuit element in question will have a rated current of not less than the value of the expected intensity of the recipient to connect.
The value of the current intensity provided in each circuit are calculated according to the formula: I = nx Ia x Fs x Fu
- No: Number of shots or receivers
- Ia: Intensity provided for making or receiving
- Fs (simultaneity factor): Ratio of total receivers simultaneously connected
- Fu (load factor): Average utilization factor of the maximum power of the receiver
Automatic protection devices for both the intensity value assigned to the short circuit. Maximum admissible intensity correspond to the circuit and short circuit at that point respectively.
The size of wire must be at least as indicated in Table 1, and also be conditioned on the voltage drop is not more than 3%. This voltage drop is calculated for an intensity of operation of the circuit equal to the rated current of the circuit breaker and for a distance corresponding to the point of use furthest from the origin of the internal equipment. The value of the voltage drop may be offset between the interior and the installation of individual referrals, so that the total voltage drop is less than the sum of the limit values specified for both, depending on the scheme used.
2. High Electrification
This applies to homes with an expected major appliances requiring install more than one circuit of any of the types described above together with a forecast of electric heating systems, air conditioning, automation, energy management and technical safety or usable areas of housing higher than 160 m2. In this case will be installed in addition to those for basic electrification, the following circuits:
- C6 additional circuit C1, for every 30 points of light
- C7 additional circuit type C2, for every 20 outlets in general use or if the floor space of housing is greater than 160 m2.
- C8 internal distribution circuit, for the electrical heating system, when there is anticipation of it.
- C9 internal distribution circuit, for the air conditioning installation, when there is anticipation of this
- C10 internal distribution circuit, for the installation of a separate dryer
- Circuit C11 internal distribution for feed automation system, technical management and energy security, where there is anticipation of it.
- C12 additional circuits either type C3 or C4, when providing, or additional circuit C5, where the number of outlets exceeds 6.
Both basic and electrification for high, be placed at least an RCD of the properties listed in paragraph 2.1 for every five circuits installed.