RKEF185

Resettable Fuse, PPTC, PolySwitch RKEF, 60 VDC, 1.85 A, 3.7 A, 12.6 s, Rectangular

⚠️ Reference pricing provided. In case of supply shortages, we will connect you with our trusted procurement partners to ensure your project's continuity.

Manufacturer: LITTELFUSE
Product type: Radial Leaded PPTCs
Thermistor Mounting:Through Hole; Product Range:PolySwitch RKEF Series; Holding Current:1.85A; Tripping Current:3.7A; Voltage Rating:60VDC; Operating Temperature Min:-40°C; Operat
SVHC: To Be Advised
Height: 18.8mm
Length: 13mm
Diameter: -
Thickness: 3.81mm
Fuse Shape: Rectangular
Lead Spacing: 5.84mm
Time to Trip: 12.6s
Trip Current: 3.7A
Product Range: PolySwitch RKEF
Voltage Rating: 60VDC
Holding Current: 1.85A
Current Rating Max: 40A
Thermistor Mounting: Through Hole
Operating Temperature Max: 85°C
Operating Temperature Min: -40°C
Automotive Qualification Standard: -

Delivery and price
Units per pack	500
Price	0.313 €
Current stock	100+
Lead time	30 days

Datasheet

**PRODUCT : RKEF185 PolySwitch® PTC Devices** DOCUMENT : SCD26920 ~~Po~~ REV LETTER: E **Overcurrent Protection Device** REV DATE: JULY 26, 2016 PAGE NO.: 1 OF 2 

## **S ecification Status: Released p** 

**Electrical Rating Voltage:  60V MAX Current:  40A MAX** 

## **Insulating Material:** 

**Cured, Flame Retardant Epoxy Polymer** 

## **Lead Material:** 

**20 AWG Tin Plated Copper** 

Marking: 

Manufacturer’s Mark 

K185 and Part Identification 

Lot Identification 

## **TABLE I. DIMENSIONS:** 

|**A**<br>**MIN**<br>**MAX**|**A**<br>**MIN**<br>**MAX**|**B**<br>**MIN**<br>**MAX**|**B**<br>**MIN**<br>**MAX**|**C**<br>**MIN**<br>**MAX**|**C**<br>**MIN**<br>**MAX**|**D**<br>**MIN**<br>**MAX**|**D**<br>**MIN**<br>**MAX**|**E**<br>**MIN**<br>**MAX**|**E**<br>**MIN**<br>**MAX**|
|---|---|---|---|---|---|---|---|---|---|
|**--**|13.0|---|18.8|4.32|5.84|7.6|---|---|3.81|
|**--**|(0.51)|---|(0.74)|(0.17)|(0.23)|(0.3)|---|---|(0.15)|



***Rounded off approximation** 

## **TABLE II. PERFORMANCE RATINGS:** 

|**I HOLD**<br>**RATED**<br>**CURRENT**|**CURRENT**<br>**RATINGS**|**CURRENT**<br>**RATINGS**|**INITIAL**<br>**RESISTANCE**<br>**VALUES**|**INITIAL**<br>**RESISTANCE**<br>**VALUES**|**TIME TO TRIP**|**ONE HOUR**<br>**POST-TRIP**<br>**RESISTANCE**<br>**STANDARD TRIP**|**TRIPPED-**<br>**STATE POWER**<br>**DISSIPATION**|
|---|---|---|---|---|---|---|---|
|**AMPERES**<br>**AT 20****C**<br>**HOLD**|**AMPERES**<br>**AT 20****C**<br>**HOLD**<br>**TRIP**||**OHMS**<br>**AT 20****C**<br>**MIN**<br>**MAX**||**SECONDS AT**<br>**20****C, 9.25A**<br>**MAX**|**OHMS**<br>**AT 20****C**<br>**MAX**|**WATTS**<br>**AT 20****C**<br>**NOMINAL**|
|**1.85**|**1.85**|**3.70**|**0.06**|**0.152**|**12.6**|**0.25**|**2.6**|



UL, TUV, CSA PS300 

Agency Recognitions: UL, TUV, CSA Reference Documents: PS300 Precedence: This specification takes precedence over documents referenced herein. Effectivity: Reference documents shall be the issue in effect on the date of invitation for bid. CAUTION: Operation beyond the rated voltage or current may result in rupture, electrical arcing or flame. 

## **Materials Information** 

## **ROHS Compliant** 

**ELV Compliant** 

**Pb-Free Halogen Free*** HF ® Oo 

* Halogen Free refers to: Br≤900ppm, Cl≤900ppm, Br+Cl≤1500ppm. 

© 2016 Littelfuse,Inc.                                                                                                    littelfuse.com Specifications are subject to change without notice. Revised July 26, 2016 

**PRODUCT : RKEF185 PolySwitch® PTC Devices** DOCUMENT : SCD26920 ~~Cd~~ REV LETTER: E **Overcurrent Protection Device** REV DATE: JULY 26, 2016 PAGE NO.: 2 OF 2 

Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, military, aerospace, medical, lifesaving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse 

© 2016 Littelfuse,Inc.                                                                                                    littelfuse.com Specifications are subject to change without notice. Revised July 26, 2016

Updated at June 9, 2026

Founded in 1927 and headquartered in Chicago, Illinois, Littelfuse is a premier global manufacturer of circuit protection, power control, and sensing technologies. Widely recognized for pioneering the first small, fast-acting protective fuse, the company has grown into an industry leader whose highly reliable components are essential to modern industrial, transportation, and consumer electronics applications worldwide. At the core of the Littelfuse portfolio is an expansive and industry-leading range of circuit protection solutions. This encompasses a massive selection of traditional fuses, fuse holders, and resettable PTC thermistor fuses designed to safely interrupt overcurrent conditions. To defend against electrical overstress, Littelfuse also provides advanced transient voltage suppression (TVS) technologies, including thousands of specialized TVS diodes, TVS varistors, and gas discharge tubes (GDTs) that ensure robust defense against voltage spikes and environmental hazards. Beyond its foundational protection components, Littelfuse manufactures a diverse array of discrete semiconductors, sensors, and switching devices. Engineers rely on their high-performance thyristors, including TRIACs and SCRs, alongside power-efficient Schottky diodes and MOSFETs for demanding power control applications. Complemented by precision proximity sensors and highly reliable reed and solid-state relays, Littelfuse delivers the critical building blocks required for secure, efficient, and complete system design.

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