Character

● Parameters control the structure of tripping ,cutting off the current selectively ;

● Contacts with high energy have a long life span ;

● Having the same shape with MCB ,small size ,making it easy to examine SPD when current is cut off ;

● Having a complex range of specifications ,being able to work with SPD of T1、T2 and T3;

● Installed with 35mm rails , meeting the demands of installation all around the world ;

● Impulse current with residual voltage ,being able to equal fuses ;

Technical Parameters

Selection of the order

The type and the order of the back-up protectors
	Protection level	limp In	The dimension of width	Order code	Electrical signal
T08/100	T1	25KA（10/350μs）	36mm	4110100004
		15KA（10/350μs）	18mm	4110100003
T08/80	T2	80kA(8/20μs)	8mm	4110100002
T08/60	T2/T3	60kA(8/20μs)	8mm	4110100001

product certification

working principle

SCB, the exclusive external disconnector of SPD ,is a kind of equipment which is developed according to the article 430.3 in the IEC61643-4-43:adopt suitable over –current protection devices before dangers caused by circuit .it mainly solve problems that when follow currents or leakage currents take place in SPD ,SCB can trip quickly ,while lightning currents pass ,SCB does not trip ,SCB ensures that SPD does not cause a fire and the lighting protection of equipment lasts long ,solving the problems that there is protection blind in current widely used fuses and breakers which are used as external disconnectors .SCB is the ideal matching devices of voltage switching type SPD、voltage limiting type SPD used low-voltage power supply system.

All over the world are taking part in solving the problem:

When the ignition of SPD takes place ,external breakers do not disconnect .And when surge flows through SPD ,external breakers disconnect mistakenly.

German conducted the experiment of lightning current impact on fuses and breakers in 1997.Geeen area means connection ,orange area means uncertainty ,and red area means disconnection .

IEC drafted and revised the standard of SPD .Sub-committee 37A set up Task Force 12 in Austria-Vienna meeting .solving the matching problem between breakers and SPD.

Many countries around the word launched the study the degeneration problem of MOV(metal oxide varistor) SPD .

1. When the degeneration of SPD takes place ,the display of electrical parameters is that Uc value reduces .

2. When Uc value reduces to the voltage of power ,leakage current will increase sharply.

3. When power appears abnormal temporary over-voltage ,it will cause SPD to start.

4. When normal current of more than 5A flows through SPD ,the speed of ignition is faster than heat transfer.

When current more than 5A passes through SPD ,it may catch fire immediately ,so the SPD needs a switch protector which releases quickly when current of more than 5A passes through to avoid fire !

It demands that when lightning current flows through ,it does not trip ,which keeps the effectiveness in the work .

When the degeneration of SPD takes place or before leakage current caused by abnormal power reaches 5A ,it can trip quickly .

can solve problem

The mismatching between lightning protection devices and fuse or breaker ?

The traditional method is to link a fuse or breaker in series in front of lightning protection devices, there would be four mismatching aspects if doing so.
1. When lightning protective devices degrade or there is over voltage occurring in the distribution circuit, lightning protective devices will become shor t-circuited to grounding and Fuses or breakers can not disconnect quickly
2. When lightning occurs, fuses or breakers can not stand temporar y energy of lightning current, for they were used as components of power distribution in the early design. So it is easy to cause them trip or explode, making lightning protective ineffective.
3. When lightning current go through breakers, the Up value is ver y high and lightning protective devices can’ t protect equipment well
4. Fuses or breakers can not disconnect in the power be installed line of transformer . When shor t circuit takes place, they can not break quickly.

SCB Can Solving Four Problems at the same time

SCB, linked in series in front of SPD can Solving Four Problems at the same time .

1. When lightning protective devices degrade or there is overvoltage occurring in the distribution circuit, SCB can disconnect quickly to avoid lightning protective devices from firing. The breaking current is less than 3 A
2. When lightning current goes through, the SCB linked in series in front of SPD can keep no tripping and no damage under the lightning current of 100KA, keeping the SPD in working order.
3. When lightning current goes through SCB, the Up value is very low, be equal to copper with
same length.
4. The breaking capacity of SCB exceeds plastic breakers, up to 100KA.

There is a big difference in time and amplitude between power frequency current and surge .SCB makes good use of this two parameters to control electromagnets ,achieving the function of tripping.

1.When alternating current flows through ,electromagnet can trip selectively to cut off alternating current .

2.Because the speed of surge is too fast ,surge ends before electromagnet takes action .so electromagnet is in stable state and SCB does not trip.

The residual voltage of SCBs、MCBs and fuses under impulse current

	Fuse			MCB				SCB
impulse current (8/20μs)	Gg32A Φ14×51	Gg40A Φ14×51	Gg63A Φ14×5	EA9AN1		DZ47		SCB
				C32	C63	C32	C63
In=6kA	107.5V	107.5V	95.5V	179V	167V	179V	101.3V	113.3V
In=6kA	197V	196V	173V	310.5V	220.9V	304.5V	185V	81.6V
In=20kA	Break	Break	358.2V	597V	441.7V	608.9V	405.9V	340.3V

Typical applications

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