Jiaxing supply afci-10a / 3P + n fault arc circuit breake

  Jiaxing supplies afci-10a / 3P + n fault arc circuit breaker, fuse group disconnector, manual double throw disconnector, dual power automatic transfer switch, control and protection switch, AC contactor
1
Technical parameters of afci-10a / 3P + n fault arc circuit breaker:
 

Project	main technical parameters of afci-10a / 3P + n
rated working voltage (UN)	AC 220V(1P+N 2P) 、AC380V(3P+N)
rated frequency	50Hz
rated current (in)	6A、10A、16A、20A、25A、32A、40A、50A、63A
4 5KA(6KA/10KA)
number of poles	1P+N、 2P 、3P+N
communication method	RF2 4G、CAN BUS
basic protection functions	it can cut off the power supply of short circuit, overload arc and leakage fault in the load power supply line in time
has other functional features	it has led status indication, fault memory, load LED indication function, leakage indication function, wireless networking and power management function
tripping characteristics	C-type tripping curve characteristics (5 ~ 10) in instantaneous tripping
mechanical and electrical life:	> 9000 times

 
2、  Type of electrical fire
In order to study the characteristics of fire accidents in China, statistical methods are used to analyze the number of accidents, casualties, property losses, regional, urban and rural comparison, accident grade, accident cause, accident time and accident site
The results show that the number of fire accidents and casualties in China showed a downward trend from 2013 to 2016, and the number of large and above fire accidents decreased year by year; The number of fire accidents is the most in the eastern region and the least in the northeast region; The distribution of towns and townships is generally uniform; January to march is the peak period of fire accidents in China; The number of casualties caused by residential and dormitory fires far exceeds that of other places, the problem is prominent, and there is no obvious improvement trend in recent years
Based on these characteristics, this paper puts forward relevant measures and suggestions to reduce fire accidents in China

Electrical fire generally refers to the fire caused by electrical lines, electrical equipment and devices
Thermal energy released due to failure of power supply and distribution equipment (such as electrical failure)
High temperature caused by barrier, arc and energy released without fault (such as electricity)
The hot surface of a hot appliance)
Ignite the body or body under combustion conditions
Fire caused by other combustibles

3、  An important inducement of electrical fire & mdash& mdash; Fault arc
3
1 fault arc
Arc is the product of non-contact discharge of conductors with different potentials, which widely exists in power distribution system
According to the fire data of the Fire Department of the Ministry of public security, about 50% of the faults in electrical fire, such as loose electrical connection, aging insulation and material failure, are arc faults that cannot be effectively protected by traditional electrical protection elements such as circuit breakers and may cause fire
According to the statistics of the American Fire Protection Association: & ldquo; Electrical problem is the second culprit of fire, and fault arc is one of the important inducements of electrical fire& rdquo; NEC (National Electrical Code) data show that about 40% of residential fires are caused by fault arc
The National Association of state fire marshals (NASFM) also pointed out in the investigation and Research Report on the causes of electrical fires that 83% of electrical fires are caused by fault arc

3．2
Generation and harm of fault arc
Arc is a gas discharge phenomenon
It is an instantaneous spark generated by current breakdown of insulating medium
It is characterized by high temperature
During arc discharge, a large amount of heat will be generated
With the sputtering of high-temperature residues, it is very easy to ignite the surrounding inflammables and explosives, resulting in fire and even explosion
After testing, it is found that the temperature of the arc generated by a current slightly greater than 0
5A can be as high as 3000oc, which is enough to ignite any combustibles
Moreover, when the maintenance voltage of the arc is as low as 20V, the arc can still exist continuously and stably, which is the main cause of the ignition source of building electrical fire

4
Relevant foreign standards and Applications
The use of fault arc protection device in foreign countries is not long, and the fault arc circuit breaker (afci-10a / 3P + n) first used in the United States is only about 20 years
Afci-10a / 3P + n is considered to be electrical hazard after being used in residence
Fire protection is effective
In 1999, UL formulated and promulgated the first standard of fault arc protection: UL 1699 (standard for fault arc circuit breaker)
The National Electrical Code (NEC) 2002 edition establishes the fault code
Mandatory regulations on the use of arc protection (NEC 2002 & mdash; 210
12a, b): ① all branches installed in the bedroom shall be equipped with fault arc circuit breakers to protect the whole branch; ② The indoor air conditioner connected by single-phase power line and plug needs to be equipped with arc protection device
NEC 2008 (210
12b) version expands the application scope of fault arc circuit breaker and requires all branch circuits to be installed with fault arc circuit breaker
In 2003, the National Fire Protection Association (NFPA) made the following conclusion on the installation of fault arc circuit breaker: fault arc circuit breaker can prevent 75% - 80% of electrical line fires
After August 1, 2004, the United States requires that household air conditioners sold in the market must be equipped with power plugs with arc protection function
2007
The National Electrical Manufacturers Association (NEMA) released the white paper "arc fault circuit breaker improves home safety"
The white paper believes that arc fault circuit breaker can prevent the occurrence of fire at the initial stage, which is & ldquo; Nip in the bud & rdquo; Technology
In 2014, UL 474 of the United States required that dehumidifiers sold to North America after 2017 must be equipped with protectors with fault arc protection function
Compared with the application of fault arc circuit breaker in the United States, the European International Electrotechnical Commission did not launch the protection standard of fault arc until 2013: iec62606 & mdash- 2013(Generalrequirementsforarcfaultdetection devices)。 The research on arc detection and protection in many countries in Asia started relatively late
The drafting of technical standards for fault arc fire protection is also under way

5
Relevant domestic standards
With the design standard GB 50116 & mdash; With the promulgation of code for design of automatic fire alarm system in 2013, China's relevant departments have successively formulated and issued two national standards related to fault arc detection: GB / t31143 & mdash; 2014 General requirements for arc fault protection apparatus (afci-10a / 3P + n) (implemented on April 1, 2015); GB 14287．4— 2014 electrical fire monitoring system Part 4: fault arc detector (implemented on June 1, 2015)
At present, the technical performance and relevant detection methods of the above standards are applicable to afci-10a / 3P + n products with rated voltage not exceeding 240V, rated current (, n) not exceeding 63A and terminal installation

6  Development status of fault arc protection technology at home and abroad abroad abroad, the United States first proposed arc protection technology, Eaton, Siemens, Germany State instruments, Schneider, G , E company has also launched fault arc protection products (afci-10a / 3P + n), but these products are only applicable to North American power grid AC120 60Hz
Moreover, the high false alarm rate of products also hinders the development of fault arc products
Korea K E  S  Co company has launched afci-10a / 3P + n products, but it only produces products suitable for 120V 60Hz lines, which is not suitable for China's national conditions
At home
The research on fault arc protection products suitable for the Chinese market has just started
More than a dozen companies are developing products
Although most of them have not yet launched mature products on the market, some companies have started from the causes of fault arc, through the fault arc detection signal source, low-voltage distribution line system transmission function, fault arc signal attenuation theory, reliability Through the research and test of some columns such as sampling transformer, the effective criterion of fault arc is found out, and the high reliability afci-10a / 3P + n product is developed

 
7
In 2013, IEC International Electrotechnical Commission and China low voltage electrical Standardization Committee launched corresponding international and national standards for fault arc circuit breaker (afci-10a / 3P + n), and the state fire administration launched national standards for fault arc detector (afci-10a / 3P + n), promoting China's research and development of this technology in the field of low-voltage electrical appliances and electrical fire monitoring

In 2016, our team took the lead in successfully developing practical intelligent fault arc protection technology in China
It has complete domestic intellectual property rights and is particularly suitable for China's power grid conditions
At present, it is at the leading level in China

  It can be predicted that in the near future, all low-voltage electrical lines and household appliances at home and abroad will actively adopt mature and reliable fault arc protection technology (device) & mdash& mdash; Just like using short-circuit protector, overload protector and leakage protector, it has become the basic equipment in the field of low-voltage power grid and electrical safety

 
8
Conclusion
In order to make afci-10a / 3P + n products successfully pass the test and better enter the market, it is also necessary to improve the following two aspects: on the one hand, improve the arc detection algorithm
Due to the complexity of arc waveform, the current algorithms have more or less defects in varying degrees
We can try new algorithms or integrate existing algorithms through the analysis of specific test data to better solve the problem of arc judgment
On the other hand, solve the product misoperation