Industrial & Electrical Fuses

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QS High-Speed Round Body Fuses

Littelfuse QS Series High-Speed Round Body Fuses provide circuit protection at the fast speeds required by modern semiconductor devices. These fuses offer extreme current limiting protection against power surges and balanced performance for longevity. L50QS and L70QS series high-speed fuses use arc-quenching stone sand to provide lower arc voltages while offering reduced l²t let-through energy and peak currents. This improved performance differentiates the QS series from other power fuses, including previous S series fuses. Universal mount bolted-end terminals give these RoHS and REACH-compliant fuses the ability to replace existing fuses in the field easily. Littelfuse QS series fuses are ideal for drive panel builders, the oil and gas industry, pulp and paper industries, motor controls, wastewater treatment plants, and other large factory settings.

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Part #

Industrial & Electrical Fuses 90A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS090.T
Littelfuse
1: S/220.12
62In Stock

Mfr. Part #
L50QS090.T

Mouser Part #
576-L50QS090.T

Littelfuse

Industrial & Electrical Fuses 90A 500VAC 500VDC FF L50QS POWR-SPEED

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Datasheet

62In Stock

S/220.12

S/192.80

S/156.05

S/149.74

S/143.52

Min.: 1
Mult.: 1

Semiconductor Fuses

90 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 600A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS600.X
Littelfuse
1: S/1,349.45
16In Stock

Mfr. Part #
L70QS600.X

Mouser Part #
576-L70QS600.X

Littelfuse

Industrial & Electrical Fuses 600A 700VAC 700VDC FF L70QS POWR-SPEED

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Datasheet

16In Stock

S/1,349.45

S/1,132.37

Min.: 1
Mult.: 1

Semiconductor Fuses

600 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 350A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS350.V
Littelfuse
1: S/549.19
60In Stock

Mfr. Part #
L50QS350.V

Mouser Part #
576-L50QS350.V

Littelfuse

Industrial & Electrical Fuses 350A 500VAC 500VDC FF L50QS POWR-SPEED

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Datasheet

60In Stock

S/549.19

S/455.97

S/419.61

S/365.16

S/354.41

Min.: 1
Mult.: 1

Semiconductor Fuses

350 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 450A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS450.X
Littelfuse
1: S/1,359.88
5In Stock

Mfr. Part #
L70QS450.X

Mouser Part #
576-L70QS450.X

Littelfuse

Industrial & Electrical Fuses 450A 700VAC 700VDC FF L70QS POWR-SPEED

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Datasheet

5In Stock

S/1,359.88

S/1,205.20

Min.: 1
Mult.: 1

Semiconductor Fuses

450 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 150A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS150.V
Littelfuse
1: S/381.93
147In Stock

Mfr. Part #
L50QS150.V

Mouser Part #
576-L50QS150.V

Littelfuse

Industrial & Electrical Fuses 150A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

147In Stock

S/381.93

S/318.52

S/293.92

S/248.30

S/228.61

Min.: 1
Mult.: 1

Semiconductor Fuses

150 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 200A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS200.V
Littelfuse
1: S/390.22
39In Stock

Mfr. Part #
L50QS200.V

Mouser Part #
576-L50QS200.V

Littelfuse

Industrial & Electrical Fuses 200A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

39In Stock

S/390.22

S/324.13

S/300.15

S/248.30

S/228.61

Min.: 1
Mult.: 1

Semiconductor Fuses

200 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 250A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS250.V
Littelfuse
1: S/609.14
23In Stock

Mfr. Part #
L50QS250.V

Mouser Part #
576-L50QS250.V

Littelfuse

Industrial & Electrical Fuses 250A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

23In Stock

S/609.14

S/528.25

S/487.89

S/385.05

S/354.41

Min.: 1
Mult.: 1

Semiconductor Fuses

250 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 300A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS300.V
Littelfuse
1: S/600.92
27In Stock
33Expected 10/5/2026

Mfr. Part #
L50QS300.V

Mouser Part #
576-L50QS300.V

Littelfuse

Industrial & Electrical Fuses 300A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

27In Stock

33Expected 10/5/2026

S/600.92

S/505.09

S/465.70

S/381.62

S/354.41

Min.: 1
Mult.: 1

Semiconductor Fuses

300 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 600A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS600.X
Littelfuse
1: S/889.90
56In Stock

Mfr. Part #
L50QS600.X

Mouser Part #
576-L50QS600.X

Littelfuse

Industrial & Electrical Fuses 600A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

56In Stock

S/889.90

S/740.86

S/675.54

S/595.90

Min.: 1
Mult.: 1

Semiconductor Fuses

600 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 100A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS100.V
Littelfuse
1: S/511.94
21In Stock

Mfr. Part #
L70QS100.V

Mouser Part #
576-L70QS100.V

Littelfuse

Industrial & Electrical Fuses 100A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

21In Stock

S/511.94

S/411.94

S/383.26

S/323.74

S/298.01

Min.: 1
Mult.: 1

Semiconductor Fuses

100 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 150A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS150.V
Littelfuse
1: S/721.59
18In Stock

Mfr. Part #
L70QS150.V

Mouser Part #
576-L70QS150.V

Littelfuse

Industrial & Electrical Fuses 150A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

18In Stock

S/721.59

S/611.82

S/564.88

S/455.89

Min.: 1
Mult.: 1

Semiconductor Fuses

150 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 200A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS200.V
Littelfuse
1: S/652.03
48In Stock

Mfr. Part #
L70QS200.V

Mouser Part #
576-L70QS200.V

Littelfuse

Industrial & Electrical Fuses 200A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

48In Stock

S/652.03

S/598.28

S/461.14

S/455.89

Min.: 1
Mult.: 1

Semiconductor Fuses

200 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 300A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS300.X
Littelfuse
1: S/1,032.29
10In Stock

Mfr. Part #
L70QS300.X

Mouser Part #
576-L70QS300.X

Littelfuse

Industrial & Electrical Fuses 300A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

10In Stock

S/1,032.29

S/869.23

S/782.98

S/667.84

Min.: 1
Mult.: 1

Semiconductor Fuses

300 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 35A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS035.T
Littelfuse
1: S/245.85
46In Stock
73Expected 10/14/2026

Mfr. Part #
L50QS035.T

Mouser Part #
576-L50QS035.T

Littelfuse

Industrial & Electrical Fuses 35A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

46In Stock

73Expected 10/14/2026

S/245.85

S/209.38

S/192.60

S/164.07

View

Min.: 1
Mult.: 1

Semiconductor Fuses

35 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 60A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS060.V
Littelfuse
1: S/403.96
25In Stock

Mfr. Part #
L70QS060.V

Mouser Part #
576-L70QS060.V

Littelfuse

Industrial & Electrical Fuses 60A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

25In Stock

S/403.96

S/346.43

S/319.85

S/255.62

S/235.34

Min.: 1
Mult.: 1

Semiconductor Fuses

60 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 60A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS060.T
Littelfuse
1: S/249.55
11In Stock
16Expected 10/29/2026

Mfr. Part #
L50QS060.T

Mouser Part #
576-L50QS060.T

Littelfuse

Industrial & Electrical Fuses 60A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

11In Stock

16Expected 10/29/2026

S/249.55

S/204.40

S/190.97

S/158.07

View

Min.: 1
Mult.: 1

Semiconductor Fuses

60 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 80A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS080.T
Littelfuse
1: S/274.69
11In Stock
12Expected 10/22/2026

Mfr. Part #
L50QS080.T

Mouser Part #
576-L50QS080.T

Littelfuse

Industrial & Electrical Fuses 80A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

11In Stock

12Expected 10/22/2026

S/274.69

S/242.39

S/224.21

S/173.92

View

Min.: 1
Mult.: 1

Semiconductor Fuses

80 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 400A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS400.V
Littelfuse
1: S/551.57
6In Stock
32Expected 10/5/2026

Mfr. Part #
L50QS400.V

Mouser Part #
576-L50QS400.V

Littelfuse

Industrial & Electrical Fuses 400A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

6In Stock

32Expected 10/5/2026

S/551.57

S/473.83

S/465.70

S/365.74

View

Min.: 1
Mult.: 1

Semiconductor Fuses

400 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 450A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS450.X
Littelfuse
1: S/925.29
4In Stock

Mfr. Part #
L50QS450.X

Mouser Part #
576-L50QS450.X

Littelfuse

Industrial & Electrical Fuses 450A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

4In Stock

S/925.29

S/767.02

S/707.07

S/584.19

Min.: 1
Mult.: 1

Semiconductor Fuses

450 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 50A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS050.V
Littelfuse
1: S/403.96
8In Stock

Mfr. Part #
L70QS050.V

Mouser Part #
576-L70QS050.V

Littelfuse

Industrial & Electrical Fuses 50A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

8In Stock

S/403.96

S/346.39

S/300.38

S/255.62

S/235.34

Min.: 1
Mult.: 1

Semiconductor Fuses

50 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 70A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS070.V
Littelfuse
1: S/511.94
6In Stock
85Expected 11/24/2026

Mfr. Part #
L70QS070.V

Mouser Part #
576-L70QS070.V

Littelfuse

Industrial & Electrical Fuses 70A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

6In Stock

85Expected 11/24/2026

S/511.94

S/424.59

S/391.51

S/336.39

View

Min.: 1
Mult.: 1

Semiconductor Fuses

70 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 125A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS125.V
Littelfuse
1: S/721.55
6In Stock

Mfr. Part #
L70QS125.V

Mouser Part #
576-L70QS125.V

Littelfuse

Industrial & Electrical Fuses 125A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

6In Stock

S/721.55

S/598.28

S/551.61

S/455.89

Min.: 1
Mult.: 1

Semiconductor Fuses

125 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 250A 700VAC 700VDC FF L70QS POWR-SPEED

L70QS250.X
Littelfuse
1: S/1,032.29
1In Stock

Mfr. Part #
L70QS250.X

Mouser Part #
576-L70QS250.X

Littelfuse

Industrial & Electrical Fuses 250A 700VAC 700VDC FF L70QS POWR-SPEED

Learn More

Datasheet

1In Stock

S/1,032.29

S/876.98

S/808.43

S/667.84

Min.: 1
Mult.: 1

Semiconductor Fuses

250 A

700 VAC

Fast-Acting Fuses

700 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L70QS

Industrial & Electrical Fuses 70A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS070.T
Littelfuse
1: S/282.87
11In Stock

Mfr. Part #
L50QS070.T

Mouser Part #
576-L50QS070.T

Littelfuse

Industrial & Electrical Fuses 70A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

11In Stock

S/282.87

S/242.39

S/224.21

S/173.92

View

Min.: 1
Mult.: 1

Semiconductor Fuses

70 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

Industrial & Electrical Fuses 225A 500VAC 500VDC FF L50QS POWR-SPEED

L50QS225.V
Littelfuse
1: S/609.14
3In Stock

Mfr. Part #
L50QS225.V

Mouser Part #
576-L50QS225.V

Littelfuse

Industrial & Electrical Fuses 225A 500VAC 500VDC FF L50QS POWR-SPEED

Learn More

Datasheet

3In Stock

S/609.14

S/492.48

S/457.87

S/385.05

S/354.41

Min.: 1
Mult.: 1

Semiconductor Fuses

225 A

500 VAC

Fast-Acting Fuses

500 VDC

200 kA

Bolt Down

Class aR Fuses

Without Indicator

Bulk

L50QS

QS High-Speed Round Body Fuses

Customer Service Office

Company

Resources

Support

35 A
40 A
50 A
60 A
70 A
80 A
90 A
100 A
125 A
150 A
175 A
200 A
225 A
250 A
275 A
300 A
325 A
350 A
400 A
450 A