1, The impact of circuit carrying capacity
The carrying capacity of a circuit, namely its rated current and power, is the primary factor determining the number of emergency lights installed. Each circuit has its specific upper limit, exceeding which may cause circuit overload and pose a safety hazard. Therefore, when designing emergency lighting systems, it is necessary to ensure that the total power of the lamps on each circuit does not exceed the rated power of the circuit.
Specifically, the rated current and power of a circuit depend on the specifications and diameter of the wires, as well as the overall design of the power supply system. Under normal circumstances, the wire specifications and diameters of emergency lighting systems are selected based on the expected load current to ensure the safe operation of the circuit. At the same time, the overall design of the power supply system will also take into account the demand for emergency lighting, ensuring that it can be quickly activated and provide sufficient lighting in emergency situations.
2, Consideration of rated power of lighting fixtures
The rated power of emergency lights is another key factor. Different types of emergency lighting fixtures have different rated power, which directly affects the number of fixtures that can be installed on each circuit. Generally speaking, the rated power of emergency lights includes DC24V conventional marker lights (less than or equal to 1W), DC24V evacuation lighting lights (2W, 3W, 5W, etc.).
According to the GB51348-2019 standard, when lighting fixtures are installed on the ground, each circuit should not exceed 64 lights; When lighting fixtures are installed on walls or ceilings, each circuit should not exceed 25 lights. This regulation is based on a comprehensive consideration of multiple factors such as the rated power of the lamp, the allowable rated current of the circuit, and the layout of the circuit. In practical applications, it is necessary to ensure that the total power of the lamps on each circuit does not exceed the rated power of the circuit to avoid circuit overload.
3, Limitations on wire specifications and length
The specifications and length of the wires are also important factors affecting the number of emergency light installations. The specifications of a wire determine its current capacity, while the length of the wire affects resistance and voltage drop. Longer wires can increase resistance and voltage drop, thereby affecting the power supply capacity of the circuit.
Therefore, when designing emergency lighting systems, it is necessary to fully consider the specifications and length of the wires. Choosing wires of appropriate specifications can ensure that the current capacity of the circuit meets the requirements, while controlling the length of wires reasonably can reduce the impact of resistance and voltage drop. In addition, to ensure the safety and reliability of the circuit, a certain margin is usually left to avoid power shortage in emergency situations.
4, Constraints of safety regulations and standards
When designing and installing emergency lighting systems, it is also necessary to follow relevant safety regulations and standards. These regulations and standards aim to ensure the safety and reliability of emergency lighting systems, as well as the ability to provide sufficient lighting in emergency situations.
According to the relevant provisions of GB51309-2018 standard, there are clear regulations on the number, range, rated power, and rated current of any distribution circuit that is equipped with lighting fixtures. For example, the number of connected lamps should not exceed 60, and the total rated power of the connected lamps should not exceed 80% of the rated power of the distribution circuit. These regulations aim to ensure the safe operation of circuits and avoid safety hazards such as overload and short circuit.
In addition, the installation location, spacing, and lighting range of emergency lights also need to comply with relevant safety regulations and standards. For example, on emergency evacuation routes such as escape routes, stairwells, corridors, etc., the spacing between emergency lights is usually 10-20 meters to ensure that the route is clearly visible in emergency situations.
5, Comprehensive considerations in practical applications
In practical applications, determining how many emergency lights can be installed on a circuit requires comprehensive consideration of multiple factors. This includes the carrying capacity of the circuit, the rated power of the lighting fixtures, the specifications and length of the wires, as well as safety regulations and standards. At the same time, factors such as the nature of use, area, height, and evacuation needs of the building also need to be considered.
For example, in high-rise buildings, due to the large number of floors and dense population, more emergency lights need to be installed to ensure evacuation safety in emergency situations. In some small buildings, it may only be necessary to install a small number of emergency lights to meet the demand.
Therefore, when designing emergency lighting systems, it is necessary to fully understand the actual situation and needs of the building, and conduct comprehensive analysis and calculations. By considering multiple factors comprehensively, determine a reasonable number and layout plan for the installation of emergency lights to ensure sufficient lighting and evacuation instructions can be provided in emergency situations.
