Electrical networks of apartments are extremely rarely divided into power and lighting panels. Typically, such equipment is located in one building. A similar situation occurs in offices and small industrial premises.
Network separation
Despite this, in some situations it is necessary to separate the power and lighting networks for several reasons:
- The need to create emergency power.
- Installation of devices that control lighting.
- Indoor conditions.
- Location of cable routes.
- Ease of use.
In these situations, only shields are installed for the operation of lighting devices and marked with the abbreviation SHO.
Lighting board design
The same requirements apply to lighting boards as to distribution boards. Power supply is carried out through a knife switch or an automatic input switch, designed for the load created by all devices connected to the shield. Power line of the shield when using a knife switchmust be protected by a circuit breaker, the protection zone of which must cover the electrical wiring stretched to the outgoing line breakers.
Outgoing lines are equipped with their own circuit breakers, the rated current of which is calculated based on the total connected load. It is permissible to connect several outgoing cables to one circuit breaker, however, when repairing wiring or lighting, you will have to turn off all powered devices, and therefore you should not save on the number of machines.
Lighting wiring, designed in lighting, is three-wire. Luminaires are powered from the conductor of the working zero and the phase conductor. The conductor of the working zero in the cable is made in blue. Housings of lighting fixtures are grounded with a yellow-green conductor, which is part of a three-core protective cable. It is forbidden to connect the neutral conductor and the luminaire body.
In the lighting board there are two tires designed to connect neutral conductors: N - for working conductors and PE - for protective conductors. Reflector grounding is not required if the body of the lighting fixture is made of non-conductive material and the reflector is made of metal. However, in any case, a three-core cable is used, as in the arrangement of sockets without a grounding contact.
Power boards for portable lights
Portable lamps located in high-risk areas are powered by voltagenot more than 50 V. For this purpose, step-down transformers are installed that convert the voltage.
Specially for such transformers, special shields of a special design are produced with the following components:
- Step-down transformer that converts the voltage to the desired one.
- A circuit breaker designed to protect the winding from high voltage.
- Circuit breaker for protection of lines on the low voltage side of the transformer.
- Socket for portable appliances.
Not only sockets are connected to the transformer, but also cable lines leading to stationary lighting fixtures. Low voltage luminaires are most often installed in rooms with a high risk of electric shock.
Lamps operating from networks with a voltage of not more than 12 V are installed in the following cases:
- Small spaces.
- Uncomfortable working position.
- Constant worker contact with grounded metal structures.
The step-down transformer can be installed in lighting boards used to connect general lighting.
Outdoor lighting boards
Unlike a conventional lighting board, the outdoor one is equipped with an automatic or manual notification device. To control outdoor lighting in automatic mode, use:
- Photo relay. Responds to the level of illumination injurisdictional territory.
- Sound sensors.
- Motion sensors. They detect the appearance of people or animals in the illuminated area.
- Annual or monthly relays programmed to turn on the light at a certain time, changing during the month or year.
- Relay that turns on the lighting depending on the geographical coordinates of its installation.
Manual control
The transition to manual lighting control is carried out in the following cases:
- To repair the network during the daytime.
- To activate lighting when the control relay fails.
- Turning on the lighting in situations where the control relay does not work according to the specified conditions.
Switches are placed on the door or side surface of the lighting board, thanks to which the transition to manual control is carried out. There are several ways to manually turn on:
- Indoor or outdoor switch.
- Transferring the manual control key to one of the positions.
- Pushbutton control station - industrial option.
The operation of the control relay depends on sensors located in the most convenient places. Often, a photorelay is placed under the shields and lighting poles. Sensors are connected to the circuit with cables using terminal blocks mounted on a DIN rail.
If the load connected to the outdoor lighting panel exceeds the maximum allowable, then it is connected through the starter. In suchIn this case, the relay is responsible for turning on the starter, which, in turn, turns on the lights.
Emergency lighting boards
Emergency lighting is a completely self-contained system with independent power, which is pulled from the input switchgear. Its connection is made through an automatic transfer system powered by two independent sources.
Emergency lighting, unlike the working one, is not turned off manually: switches are not installed after the lighting board. Such lighting either constantly works, or turns on automatically using magnetic starters or automation.
Shield placement
The requirements for the location and installation of lighting boards are as follows:
- Shields are installed at a distance of one meter from sewer communications, gas pipelines and water pipes. At the same time, the room in which the control room is located should not be subject to flooding. If the operation of the lighting board and power cabinets will be carried out in a room that can be flooded, then they are installed above the possible flood limit.
- Much depends on the correct choice of switchboard. When selecting, the method of mounting the lighting panel is taken into account - built-in or hinged. The embedded method is considered the most convenient, since the structure installed in this way takes up a minimum of free space and additionallyprotected from temperature and mechanical influences.
- When installing a switchboard yourself, you must take into account the material from which it is made. Its choice is based on the location of the switchboard: if it is made of combustible materials, then the shield itself must be made of steel. If the shield is installed on a base made of non-combustible materials, then it can be made from low-flammable materials.
- Outdoor lighting boards are installed at a height of 20 centimeters from the ground or concrete base. If there is a high probability of snow drifts, then the shields are installed on a special foundation.
- Equipped with impulse relays, counters and measuring devices, outdoor panels must be equipped with heating. The exception is switchboards with devices that retain functionality at temperatures below 5 degrees.
Lighting board OSHV-12
The shield is made of metal, in the body of which there is a mounting panel designed for installation of input and distribution equipment.
The OSHV shield has a high level of safety and reliability and distinctive features:
- the possibility of installing an introductory switch;
- fixed wall mount design.
ShRO-63A lighting shield
Shield for receiving and transmitting electrical energy in lighting equipment located in administrative, industrial and public buildings. Also canbe used to protect circuits from overloads and short circuits. Connects to three-phase electrical networks and provides operation of four- and five-wire systems with grounding.
