High-voltage current limiting fuse for transformer protection（DIN stardand）

This product applies to the indoor AC 50 ~ 60Hz system with the rated voltage of 3.6~40.5kV, and may be used along with other switching devices (such as load switch, vacuum contactor, etc.) as short-circuit and overload protection element for the power transformer and other power equipment. The product is also essential for the high-voltage switchgear, ring main unit, high/low-voltage pre-installed substation.

Model

GB model：XRNT3A-□/□-50

Overseas equivalent model:

High-voltage current limiting fuse for transformer protection（DIN stardand）

Basic parameters

Product Model	Equivalent Model	Rated Voltage (kV)	Rated Current of Fuse Element (A)	Standard Size		Rated Breaking Current (kA)
Product Model	Equivalent Model	Rated Voltage (kV)	Rated Current of Fuse Element (A)	L(mm)	φA(mm)	Rated Breaking Current (kA)
XRNT3A-7.2	SDODJ	7.2	3.15, 6.3, 10, 16, 20, 25, 31.5, 40	192	φ51	50
	SEODJ		50, 63, 80		φ66
	SFODJ		100, 125		φ76
	SXODJ		160, 200		φ88
	SDLDJ		6.3, 10, 16, 20, 25, 31.5, 40, 50	292	φ51
	SELDJ		63, 80, 100		φ66
	SFLDJ		125, 160		φ76
	SXLDJ		200, 250, 315		φ88
	SEMDJ		100, 125	442	φ66
	SFMDJ		160, 200		φ76
	SXMDJ		250, 315, 355		φ88
XRNT3A-12	SDODJ	12	1, 2, 3.15, 6.3, 10, 12	192	φ51	50
	SELDJ		16, 20, 25, 31.5, 40		φ66
	SFODJ		50, 63		φ76
	SDLDJ		3.15, 6.3, 10, 16, 20, 25, 31.5, 40	292	φ51
	SELDJ		50, 63, 80		φ66
	SFLDJ		100, 125		φ76
	SXLDJ		160, 200		φ88
	SDMDJ		6.3, 10, 16, 20, 25, 31.5, 40, 50	442	φ51
	SEMDJ		63, 80, 100		φ66
	SFMDJ		125, 160		φ76
	SXMDJ		200, 250		φ88
XRNT3A-24	SDLDJ	24	2, 3.15, 6.3, 10, 12	292	φ51	31.5
	SELDJ		16, 20, 25, 31.5, 40		φ66
	SFLDJ		50, 63		φ76
	SDMDJ		6.3, 10, 16, 20, 25, 31.5, 40	442	φ51	50
	SEMDJ		40, 50, 63		φ66
	SFMDJ		63, 80		φ76
	SXMDJ		100, 125		φ88
	SFQDJ		63, 80, 100	537	φ76
	SXQDJ		125, 160	537	φ88
XRNT3A-40.5	SDMDJ	40.5	2, 3.15, 6.3, 10, 12	442	φ51	31.5
	SDQDJ		2, 3.15, 6.3, 10, 16, 20	537	φ51
	SEQDJ		20, 25		φ66
	SFQDJ		31.5, 40		φ76
	SXQDJ		50, 56, 63		φ88

Main technical data

1. The fuse under specified operating conditions is able to reliably break any fault current from the minimum breaking current to the rated breaking current.

2. This product applies to the indoor AC 50 ~ 60Hz system.

3. Time - current characteristic curve, as shown in Fig. 2, Fig. 3 and Fig. 4, the part above the minimum breaking current is indicated with dotted line.

4. Current limiting characteristic curve is as shown in Fig. 5.

5. I²t characteristic curve is as shown in Fig. 6.

Fig. 2 XRNT3A-12 time - current characteristic curve

Fig. 3 XRNT3A-24 time - current characteristic curve

Fig. 4 XRNT3A-40.5 time - current characteristic curve

Fig. 5 XRNT3A current limiting characteristic curve

Fig. 6 XRNT3A I²t characteristic curve

Selection of fuse

General selection principle for primary fuse of transformer

Rated Voltage (kV)	Rated Capacity of Transformer (kVA)
	100	125	160	200	250	315	400	500	630	800	1000	1250	1600	2000
	Rated Current of High-voltage Fuse (A)
6/7.2	16	20	20	25	31.5	40	50	63	80	100	125	160	200	250
10/12	10	16	16	20	25	31.5	40	50	63	80	80	100	125	160
15/17.5	6.3	10	10	16	16	20	25	31.5	40	50	80	80	100	125
20/24	6.3	10	10	10	16	16	20	25	31.5	40	50	63	80	100
35/40.5	3.15	6.3	6.3	6.3	10	10	16	16	20	25	31.5	40	50	56

Outline drawing of non-standard fuse link

Fig. 7 XRNT3A-40.5/6.3A～50A

Fig. 8 XRNT3A-40.5/6.3A～50A

XRNT