PFRA.300.3 Polymeric PTC Resettable Fuse 30V 3A Radial

Part Overview

The PFRA.300.3 is a polymeric PTC resettable fuse manufactured by SCHURTER Inc., rated for 30V maximum voltage with a 3A hold current (Ih). This component is classified as obsolete, though 713 pieces remain in stock as new original inventory. The PFRA.300.3 operates through a radial, disc-type package suitable for through-hole mounting applications requiring overcurrent protection in the 3A range at 30V.

Due to the obsolete product status, equivalent and substitute parts from active manufacturers provide continuity for new designs and ongoing production requirements. Suitable alternatives maintain the same electrical ratings, mechanical form factor, and thermal operating range while offering active product support and availability.

Key Parameters

Parameter	PFRA.300.3 Value
Voltage - Max	30V
Current - Hold (Ih) (Max)	3 A
Current - Trip (It)	6 A
Current - Max	40 A
Time to Trip	10.8 s
Resistance - Initial (Ri) (Min)	20 mOhms
Resistance - Post Trip (R1) (Max)	80 mOhms
Operating Temperature	-40°C ~ 85°C
Mounting Type	Through Hole
Package / Case	Radial, Disc
Size / Dimension	0.472" L x 0.118" W (12.00mm x 3.00mm)
Lead Spacing	0.201" (5.10mm)
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitute parts for the PFRA.300.3 are categorized based on electrical parameter compatibility and product status:

Direct Manufacturer Substitutes (Same Manufacturer, Active Status):

PFRA.300.2: Identical electrical specifications to PFRA.300.3 with active product status and Cut Tape packaging. All key parameters match: 30V, 3A Ih, 6A trip current, 10.8s trip time, 20 mOhms initial resistance, 80 mOhms post-trip resistance, -40°C to 85°C operating range, and identical mechanical dimensions.

Parametric Equivalents (Different Manufacturers, Identical Electrical Ratings):

RUEF300-AP and RUEF300K-AP (Littelfuse): Both rated 30V, 3A Ih, 6A trip current, 10.8s trip time, 20 mOhms initial resistance, 80 mOhms post-trip resistance, -40°C to 85°C operating range. Mechanical dimensions differ slightly (0.449" L vs 0.472" L; 0.650" height vs 0.720" height; 0.199" lead spacing vs 0.201" lead spacing). Current - Max rating is 100A versus 40A for PFRA.300.3.
MF-R300-AP and MF-R300-AP-14 (Bourns): Identical electrical specifications to PFRA.300.3 across all key parameters including voltage, hold current, trip current, trip time, resistance values, and operating temperature. Mechanical dimensions and lead spacing are identical. MF-R300-AP-14 includes AEC-Q200 automotive qualification.

Similar Parts (Lower Hold Current Rating):

MF-R250-AP, MF-R250-AP-10, and MF-R250U (Bourns): Rated 30V with 2.5A Ih (versus 3A for PFRA.300.3), 5A trip current (versus 6A), 10.3s trip time (versus 10.8s), 25 mOhms initial resistance (versus 20 mOhms), and 70 mOhms post-trip resistance (versus 80 mOhms). These parts are suitable only for applications requiring lower hold current protection.

Substitution logic is based strictly on matching: maximum voltage rating, hold current (Ih), trip current (It), trip time, initial and post-trip resistance values, operating temperature range, mounting type, and mechanical compatibility.

Parameter Comparison

Parameter	PFRA.300.3	PFRA.300.2	RUEF300-AP	RUEF300K-AP	MF-R300-AP	MF-R300-AP-14	MF-R250-AP
Manufacturer	SCHURTER Inc.	SCHURTER Inc.	Littelfuse	Littelfuse Inc.	Bourns Inc.	Bourns Inc.	Bourns Inc.
Product Status	Obsolete	Active	Active	Active	Active	Active	Active
Voltage - Max	30V	30V	30V	30V	30V	30V	30V
Current - Hold (Ih) (Max)	3 A	3 A	3 A	3 A	3 A	3 A	2.5 A
Current - Trip (It)	6 A	6 A	6 A	6 A	6 A	6 A	5 A
Current - Max	40 A	40 A	100 A	100 A	40 A	40 A	40 A
Time to Trip	10.8 s	10.8 s	10.8 s	10.8 s	10.8 s	10.8 s	10.3 s
Resistance - Initial (Ri) (Min)	20 mOhms	20 mOhms	20 mOhms	20 mOhms	20 mOhms	20 mOhms	25 mOhms
Resistance - Post Trip (R1) (Max)	80 mOhms	80 mOhms	80 mOhms	80 mOhms	80 mOhms	80 mOhms	70 mOhms
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C	-40°C ~ 85°C
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole
Package / Case	Radial, Disc	Radial, Disc	Radial, Disc	Radial, Disc	Radial, Disc	Radial, Disc	Radial, Disc
Size / Dimension	0.472" L x 0.118" W (12.00mm x 3.00mm)	0.472" L x 0.118" W (12.00mm x 3.00mm)	0.449" L x 0.118" W (11.40mm x 3.00mm)	0.449" L x 0.118" W (11.40mm x 3.00mm)	0.472" L x 0.118" W (12.00mm x 3.00mm)	0.472" L x 0.118" W (12.00mm x 3.00mm)	0.472" L x 0.118" W (12.00mm x 3.00mm)
Height - Seated (Max)	0.720" (18.30mm)	0.720" (18.30mm)	0.650" (16.50mm)	0.650" (16.50mm)	0.720" (18.30mm)	0.720" (18.30mm)	0.720" (18.30mm)
Lead Spacing	0.201" (5.10mm)	0.201" (5.10mm)	0.199" (5.05mm)	0.199" (5.05mm)	0.201" (5.10mm)	0.201" (5.10mm)	0.201" (5.10mm)
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Approval Agency	CSA, TUV, UL	cURus, TUV	CQC, CSA, TUV, UL	CQC, CSA, TUV, UL	cURus, TUV	cUL, cURus, TUV, UL	cURus, TUV

Engineering Selection Recommendations

For Direct Replacement (Obsolete to Active Transition): PFRA.300.2 is the primary recommendation for replacing PFRA.300.3. Both are SCHURTER Inc. products with identical electrical and mechanical specifications. PFRA.300.2 maintains active product status with Cut Tape packaging and higher inventory availability (744 pieces). This substitution requires no circuit redesign or PCB layout modification.

For Cross-Manufacturer Equivalents (Identical Electrical Ratings): MF-R300-AP and MF-R300-AP-14 (Bourns) provide parametric equivalence with identical electrical specifications and mechanical dimensions. MF-R300-AP-14 includes AEC-Q200 automotive qualification and Tape & Box packaging, suitable for applications requiring automotive-grade components. Both maintain ROHS3 compliance and -40°C to 85°C operating range. Lead spacing and mechanical dimensions are identical to PFRA.300.3, ensuring direct PCB compatibility.

RUEF300-AP and RUEF300K-AP (Littelfuse PolySwitch series) offer electrical equivalence with minor mechanical variations. Height is reduced from 0.720" to 0.650", and length is reduced from 0.472" to 0.449". Lead spacing differs by 0.002" (5.05mm versus 5.10mm). These parts support higher maximum current (100A versus 40A). Mechanical differences require PCB layout verification before implementation.

For Lower Current Applications: MF-R250-AP, MF-R250-AP-10, and MF-R250U are suitable only for applications where 2.5A hold current protection is acceptable. These parts are not direct substitutes for PFRA.300.3 due to reduced hold current, trip current, and resistance specifications.

Compliance Considerations: All recommended substitutes maintain ROHS3 compliance and REACH Unaffected status. Approval agencies vary: PFRA.300.2 holds cURus and TUV; MF-R300-AP holds cURus and TUV; MF-R300-AP-14 holds cUL, cURus, TUV, and UL; RUEF300-AP and RUEF300K-AP hold CQC, CSA, TUV, and UL. Select based on required regulatory certifications for the target application.

Frequently Asked Questions (FAQ)

Q: Can PFRA.300.2 be used as a direct replacement for PFRA.300.3? A: Yes. PFRA.300.2 is electrically and mechanically identical to PFRA.300.3. Both are SCHURTER Inc. products with 30V, 3A Ih, 6A trip current, 10.8s trip time, 20 mOhms initial resistance, 80 mOhms post-trip resistance, and identical physical dimensions. PFRA.300.2 is active status with higher inventory availability.

Q: What are the key electrical parameters that determine substitution compatibility? A: Substitution compatibility is determined by: maximum voltage rating (30V), hold current Ih (3A), trip current It (6A), trip time (10.8s), initial resistance Ri (20 mOhms minimum), post-trip resistance R1 (80 mOhms maximum), and operating temperature range (-40°C to 85°C). All these parameters must match for direct substitution.

Q: Are Littelfuse RUEF300-AP and RUEF300K-AP suitable replacements? A: Electrically, yes. Both match all electrical specifications of PFRA.300.3. However, mechanical dimensions differ: height is 0.650" versus 0.720", length is 0.449" versus 0.472", and lead spacing is 0.199" versus 0.201". PCB layout must be verified for compatibility before implementation.

Q: Can MF-R250-AP be used instead of PFRA.300.3? A: No. MF-R250-AP has a 2.5A hold current versus 3A for PFRA.300.3, 5A trip current versus 6A, 10.3s trip time versus 10.8s, 25 mOhms initial resistance versus 20 mOhms, and 70 mOhms post-trip resistance versus 80 mOhms. This part is suitable only for applications requiring lower current protection.

Q: What packaging options are available for active substitutes? A: PFRA.300.2 is available in Cut Tape (CT). RUEF300-AP and RUEF300K-AP are available in Cut Tape (CT). MF-R300-AP is available in Cut Tape (CT). MF-R300-AP-14 is available in Tape & Box (TB). MF-R250-AP and MF-R250-AP-10 are available in Cut Tape (CT). MF-R250U is available in Bulk.

Q: Which substitute offers the best regulatory compliance coverage? A: MF-R300-AP-14 holds the broadest approval agency coverage: cUL, cURus, TUV, and UL. This makes it suitable for applications requiring multiple regulatory certifications. RUEF300-AP and RUEF300K-AP also provide comprehensive coverage with CQC, CSA, TUV, and UL approvals.

Q: Are all substitutes ROHS3 compliant? A: Yes. All recommended substitutes—PFRA.300.2, RUEF300-AP, RUEF300K-AP, MF-R300-AP, MF-R300-AP-14, and MF-R250 series—are ROHS3 compliant and REACH Unaffected.

Q: What is the difference between MF-R300-AP and MF-R300-AP-14? A: Both are Bourns MF-R300 series with identical electrical specifications. MF-R300-AP-14 includes AEC-Q200 automotive qualification and is packaged in Tape & Box (TB), while MF-R300-AP is packaged in Cut Tape (CT). MF-R300-AP-14 is suitable for automotive applications requiring automotive-grade component certification.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message