China Emergency Light Manufacturers – Fire Emergency Lighting Requirements
With the rapid development of the national economy and computer information technology, people are increasingly demanding the comfort and safety of buildings, making urban intelligent buildings come into being. In recent years, high-rise, super-tall buildings and large-scale commercial public buildings have developed rapidly. China Emergency Light Manufacturers said: Fire emergency lighting system as an important aspect of building safety, mainly when the normal lighting is controlled or extinguished due to the failure, it can provide power for timely evacuation, security or continued work.
A. Emergency lighting can be divided into three categories according to its function.
1. Emergency lighting for evacuation. That is, when a fire occurs, the normal lighting system is extinguished due to malfunction or control. In crowded public places, lighting is installed to enable people to evacuate safely and guide people to evacuate dangerous places quickly, such as evacuation aisle lighting and Emergency lighting, etc.
2. Emergency lighting for standby lighting. That is, abnormal lighting that is used to ensure normal operation and activities continue when normal lighting is extinguished. Such as: emergency generator room, fire monitoring center and other places of lighting (monitoring center equipment is generally UPS power supply).
3. Safety lighting. That is, when normal lighting is extinguished, lighting to ensure the safety of people or objects in danger, such as emergency lighting in the operating room.
B. Emergency lighting can be divided into distributed power supply mode and centralized power supply mode according to its power supply mode.
1. At present, a large number of distributed power supply emergency lighting methods with built-in power supply are widely used in buildings. The advantage of this system is that there are no special requirements for wiring. However, with the continuous improvement of building intelligence, this kind of lighting has increasingly exposed some insurmountable shortcomings. For example, the price of a single emergency light is relatively high, and the investment in the whole project is large; the number of batteries is too high, causing high failures, and the maintenance workload is too large; it cannot be monitored by a computer, which is extremely inconsistent with the intelligence of modern buildings. When the battery power is used, the luminous efficiency is drastically lowered. Due to the above shortcomings, the emergency lighting system with its own power supply is far from meeting the requirements of the current building intelligence.
However, some of the previous and current projects have also used this kind of self-contained emergency lighting. The Chinese emergency light manufacturer has introduced its structure and working principle: this kind of luminaire mainly has common light source, emergency light source and transformer. The rectifier bridge, relay, battery and other components are composed of two-wire or three-wire connection. Since the principle of the two-wire system and the three-wire system are exactly the same, the three-wire system is explained below. One is a common zero line, one is For the fire line A, the transformer is directly transformed by the transformer without passing the switch, and then the relay and the rectifier bridge are rectified by the rectifier bridge to charge the battery. The other one is the fire wire B, which is connected to the common light source through the switch. Under normal circumstances, the A wire is always charged, and the charging of the B wire is related to the on and off of the switch. When the emergency lighting is activated, the A and B lines will be cut off. At this time, because the A line is cut off, the relay loses power, the relay contacts act, the battery is switched from the charging state to the power supply state, the normal light source is extinguished, and the emergency light source is put into use.
Since the battery power supply generally does not perform inverter conversion, it is generally an AC power supply illumination mode under normal conditions, and is a DC power supply illumination mode in an emergency situation.
2. Below, China’s emergency light manufacturer explains the centralized power supply emergency lighting mode and its superiority
The centralized power supply consists mainly of charging equipment, battery packs, inverter equipment, control equipment, and connections to the fire control center. Charging equipment and battery packs can generally be placed in low-voltage power distribution stations. The inverter equipment can be directly connected to the DC to AC inverter in the low-voltage power distribution station, or the emergency lighting power conversion box can be set on each floor to realize the DC-to-AC inverter. The control device implements various control and switching of power supply.
For the inverter part, SPWM sine wave pulse width modulation can be used. For the system with emergency lighting power conversion box on each floor, the power supply mode switching in the conversion box and the monitoring signal of the emergency lighting fixture can be connected to the fire control center to realize automatic switching and timely monitoring. It should be noted that all wires or cables connected to the emergency lighting fixtures must be flame-retardant cables in addition to the normal power supply requirements, and may be fireproof if available. The circuit connecting important fire-fighting equipment (such as: fire pump, fire elevator, anti-exhaust, smoke exhauster) is powered by dual power supply, and the circuit from the emergency bus must use fire-proof cable.
In addition, the number of circuits should be fully considered during design to ensure the reliability of power supply in the event of a fire. The power supply time of such a system can be flexibly achieved by adjusting the number of batteries. If continuous operation is required, it can be equipped with a diesel generator for power supply. Under the condition of meeting the switching time, the diesel generator can also be used for power supply. However, when there is no battery as a backup and only a diesel generator is used as the emergency power supply, the generator must be started within 15 s after the power failure. Centralized power supply emergency lighting mode can also monitor the power supply status while power supply. Through the fire control center, all fire emergency lighting equipment can be inspected. The operating status of the system can be displayed on the console at a glance, reducing the lamps. The probability of a failure.
In addition, in the scene of the fire, in order to evacuate people in time, it is necessary to change the passive and passive way of independent self-contained power supply to provide active, fast and accurate accident lighting, which can correctly guide evacuation and reduce casualties. Nowadays, many large public buildings and high-rise civil buildings have set up hundreds of emergency lights. For example, the centralized monitoring device for fire emergency power can centrally manage lighting fixtures and save investment. This also represents the future of large-scale and high-rise building fire emergency lighting. Direction of development. However, such systems must ensure the reliability of power supply in emergency situations.
C. Whether it is centralized power supply or distributed power supply, the following requirements must be met.
For fire evacuation sign lighting, the minimum illumination should not be less than 0.5Lx, and the continuous power supply time should not be less than 20min. For super high-rise buildings with a height of more than 100m, the continuous power supply time should not be less than 30min. For example: elevator car, fire hydrant, escalator safety exit, steps, evacuation corridor, indoor passage, public exit, etc. For standby lighting that continues to work temporarily, the illumination should not be less than 50% of the normal illumination, and the power supply time should not be less than 1h. For example: exhibition halls, multi-purpose halls, restaurants, business halls, dangerous places, refuge floors, etc. The standby lighting that continues to work, the illumination requirements are normal, and the power supply time is required to be continuous. For example: power distribution room, fire control room, fire pump room, generator room, battery room, telephone room, BAS central control room, etc. In addition, after the normal power supply is cut off, the power conversion time of the emergency lighting should be: evacuation lighting ≤ 15s, standby lighting ≤ 15s (financial commercial trading place ≤ 1.5s), safety lighting ≤ 0.5s.