MPN

Littelfuse 4 A Resettable Fuse, 30 V dc

RS Stock No.:: 517-6837
Mfr. Part No.:: RUEF400
Brand:: Littelfuse

Bulk discount available

Subtotal (1 pack of 10 units)*

£5.43

(exc. VAT)

£6.52

(inc. VAT)

FREE delivery for orders over £50.00

In Stock

150 unit(s) ready to ship from another location
Plus 3,300 unit(s) shipping from 23 March 2026
Plus 500 unit(s) shipping from 28 April 2026

Need more? Click ‘Check delivery dates’ to find extra stock and lead times.

Units	Per unit	Per Pack*
10 - 90	£0.543	£5.43
100 - 490	£0.428	£4.28
500 - 1490	£0.383	£3.83
1500 +	£0.374	£3.74

*price indicative

RS Stock No.:: 517-6837
Mfr. Part No.:: RUEF400
Brand:: Littelfuse

Specifications

Technical Reference

Legislation and Compliance

Product Details

Find similar products by selecting one or more attributes.

Select all	Attribute	Value
	Brand	Littelfuse
	Product Type	Resettable Fuse
	Trip Current	8A
	Voltage	30 V dc
	Current Rating	100 A
	Time to Trip	12.7s
	Hold Current	4A
	Length	14mm
	Height	19.3mm
	Width	3 mm
	Minimum Resistance	0.01Ω
	Maximum Resistance	50mΩ
	Minimum Operating Temperature	-40°C
	Power Dissipation	2.5W
	Maximum Operating Temperature	60°C
	Standards/Approvals	UL, CSA, RoHS, TUV, CQC
	Series	RUEF
	Lead Orientation	Radial

	Select all
	Brand Littelfuse
	Product Type Resettable Fuse
	Trip Current 8A
	Voltage 30 V dc
	Current Rating 100 A
	Time to Trip 12.7s
	Hold Current 4A
	Length 14mm
	Height 19.3mm
	Width 3 mm
	Minimum Resistance 0.01Ω
	Maximum Resistance 50mΩ
	Minimum Operating Temperature -40°C
	Power Dissipation 2.5W
	Maximum Operating Temperature 60°C
	Standards/Approvals UL, CSA, RoHS, TUV, CQC
	Series RUEF
	Lead Orientation Radial

PolySwitch™ RUEF & RGEF Series

PCB Wire Ended

All are UL, CSA, TUV approved

Protection of electrical and electronic circuits against excessive currents

Rapid switch from low resistance state to very high resistance with electrical overload or short circuit

Quick and automatic reset and return to low resistance state when fault condition corrected and power removed

Features:

Automatically resets itself thousands of times

Maintenance free

Small size and no fuseholder required

Main applications:

Security systems

Power supplies and transformers

Power switching devices

Automotive and medical equipment

Instrumentation and control

Computers and peripherals

Audio visual and telecommunications