RLD60P050XFF Equivalent & Substitute Parts

Part Overview

The RLD60P050XFF is a polymeric PTC resettable fuse manufactured by Littelfuse Inc., part of the POLY-FUSE® RLD60 series. This through-hole radial disc component is rated for 60V maximum voltage with a 500 mA hold current and 1 A trip current. The product is currently obsolete, making equivalent and substitute parts necessary for ongoing system support and new designs requiring similar electrical protection characteristics.

Key Parameters

Parameter	Value
Manufacturer Part Number	RLD60P050XFF
Manufacturer	Littelfuse Inc.
Series	POLY-FUSE®, RLD60
Product Status	Obsolete
Type	Polymeric
Voltage - Max	60V
Current - Hold (Ih) (Max)	500 mA
Current - Trip (It)	1 A
Current - Max	40 A
Time to Trip	4 s
Resistance - Initial (Ri) (Min)	500 mOhms
Resistance - Post Trip (R1) (Max)	1.17 Ohms
Operating Temperature	-40°C ~ 85°C
Mounting Type	Through Hole
Package / Case	Radial, Disc
Size / Dimension	0.311" Dia x 0.122" T (7.90mm x 3.10mm)
Height - Seated (Max)	0.539" (13.70mm)
Lead Spacing	0.201" (5.10mm)
Approval Agency	cURus, TUV
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution for the RLD60P050XFF is determined by the following critical electrical and mechanical parameters:

Electrical Criteria:

Voltage rating must be equal to or greater than 60V
Hold current (Ih) must match 500 mA
Trip current (It) must match 1 A
Time to trip must match 4 s
Initial resistance (Ri) and post-trip resistance (R1) must be within acceptable tolerance

Mechanical Criteria:

Through-hole radial disc mounting configuration
Lead spacing of 0.201" (5.10mm) or compatible spacing
Physical dimensions compatible with PCB layout

Compliance Criteria:

ROHS3 compliance required
Regulatory approvals (cURus, TUV, or equivalent)

Substitute parts are grouped into three categories: direct manufacturer alternatives from Littelfuse (active status), parametric equivalents from Littelfuse (matching all electrical specifications), and manufacturer-recommended alternatives from SCHURTER Inc. (with noted parameter variations).

Parameter Comparison

Parameter	RLD60P050XFF	60R050XPR	72R050XPR	RXEF050-AP	RXEF050S-AP
Manufacturer	Littelfuse Inc.	Littelfuse Inc.	Littelfuse Inc.	Littelfuse	Littelfuse
Series	POLY-FUSE®, RLD60	POLY-FUSE®, 60R	POLY-FUSE®, 72R	PolySwitch®, RXEF	PolySwitch®, RXEF
Product Status	Obsolete	Active	Active	Active	Active
Voltage - Max	60V	60V	72V	72V	72V
Current - Hold (Ih) (Max)	500 mA	500 mA	500 mA	500 mA	500 mA
Current - Trip (It)	1 A	1 A	1 A	1 A	1 A
Current - Max	40 A	40 A	40 A	40 A	40 A
Time to Trip	4 s	4 s	4 s	4 s	4 s
Resistance - Initial (Ri) (Min)	500 mOhms	500 mOhms	500 mOhms	500 mOhms	500 mOhms
Resistance - Post Trip (R1) (Max)	1.17 Ohms	1.17 Ohms	1.17 Ohms	1.17 Ohms	1.17 Ohms
Operating Temperature	-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
Package / Case	Radial, Disc	Radial, Disc	Radial, Disc	Radial, Disc	Radial, Disc
Size / Dimension	0.311" Dia x 0.122" T (7.90mm x 3.10mm)	0.311" Dia x 0.122" T (7.90mm x 3.10mm)	0.311" Dia x 0.122" T (7.90mm x 3.10mm)	0.311" Dia x 0.118" T (7.90mm x 3.00mm)	0.311" Dia x 0.118" T (7.90mm x 3.00mm)
Height - Seated (Max)	0.539" (13.70mm)	0.539" (13.70mm)	0.539" (13.70mm)	0.539" (13.70mm)	0.539" (13.70mm)
Lead Spacing	0.201" (5.10mm)	0.201" (5.10mm)	0.201" (5.10mm)	0.199" (5.05mm)	0.199" (5.05mm)
Approval Agency	cURus, TUV	cURus, TUV	cURus, TUV	CQC, CSA, TUV, UL	CQC, CSA, TUV, UL
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	Not Applicable	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)

Engineering Selection Recommendations

Primary Recommendation: 60R050XPR

The 60R050XPR is the optimal direct replacement for the obsolete RLD60P050XFF. This Littelfuse POLY-FUSE® 60R series component matches all electrical specifications exactly: 60V maximum voltage, 500 mA hold current, 1 A trip current, 4 s time to trip, and identical resistance characteristics. Physical dimensions and lead spacing are identical, ensuring direct PCB compatibility. The part is in active production status with 39,280 units in stock. It maintains cURus and TUV approvals and is ROHS3 compliant.

Secondary Recommendation: 72R050XPR

The 72R050XPR provides an alternative with higher voltage rating (72V vs. 60V) while maintaining all other electrical parameters. This Littelfuse POLY-FUSE® 72R series component is suitable for applications where higher voltage margin is beneficial. Physical dimensions match the original part. The component is active with 4,987 units in stock and carries cURus and TUV approvals with ROHS3 compliance.

Alternative Options: RXEF050-AP and RXEF050S-AP

Both RXEF series components from Littelfuse PolySwitch® line provide 72V rated alternatives with matching electrical specifications. These parts feature expanded regulatory approvals (CQC, CSA, TUV, UL) compared to the original part. Minor dimensional variations exist: thickness is 0.118" (3.00mm) versus 0.122" (3.10mm), and lead spacing is 0.199" (5.05mm) versus 0.201" (5.10mm). These differences are within typical PCB tolerance ranges. RXEF050-AP has 19,239 units in stock; RXEF050S-AP has 4,899 units. Both are active products with ROHS3 compliance.

Manufacturer-Recommended Alternatives from SCHURTER Inc.

SCHURTER PFRA series components are listed as manufacturer-recommended substitutes but feature different electrical characteristics. PFRA.010 and PFRA.010.2 operate at 100 mA hold current (versus 500 mA), PFRA.017 and PFRA.017.2 at 170 mA, and PFRA.020 and PFRA.020.2 at 200 mA. These parts are suitable only for applications where lower hold current is acceptable. All PFRA variants maintain 60V voltage rating, through-hole radial configuration, and ROHS3 compliance with cURus and TUV approvals.

Frequently Asked Questions (FAQ)

Q: Can I use the 72R050XPR or RXEF050-AP in place of the RLD60P050XFF?

A: Yes. Both components maintain identical hold current (500 mA), trip current (1 A), and time to trip (4 s) specifications. The higher voltage rating (72V) provides additional safety margin in 60V applications. Physical dimensions are compatible with standard PCB layouts. Verify that your circuit design does not depend on the specific 60V rating before substitution.

Q: What is the difference between 60R050XPR and 72R050XPR?

A: The primary difference is maximum voltage rating: 60R050XPR is rated for 60V, while 72R050XPR is rated for 72V. All other electrical parameters—hold current, trip current, time to trip, and resistance characteristics—are identical. Both are Littelfuse POLY-FUSE® series components in active production. The 72V variant provides higher voltage headroom for applications operating near the 60V limit.

Q: Are RXEF050-AP and RXEF050S-AP interchangeable?

A: Yes. Both are Littelfuse PolySwitch® RXEF series components with identical electrical specifications. The primary difference is packaging: RXEF050-AP is supplied in Cut Tape (CT), while RXEF050S-AP is also in Cut Tape (CT). Both maintain 72V rating, 500 mA hold current, and all other electrical parameters. Selection depends on inventory availability and packaging requirements.

Q: Can I use PFRA series components as substitutes?

A: PFRA series components from SCHURTER Inc. are listed as manufacturer-recommended alternatives but operate at significantly lower hold currents: PFRA.010 at 100 mA, PFRA.017 at 170 mA, and PFRA.020 at 200 mA. These are suitable only if your application can tolerate lower hold current thresholds. They maintain 60V voltage rating and through-hole radial configuration. Verify circuit requirements before substitution.

Q: What are the lead spacing differences, and do they matter?

A: The original RLD60P050XFF and Littelfuse 60R/72R series have 0.201" (5.10mm) lead spacing. RXEF series components have 0.199" (5.05mm) spacing. This 0.002" difference is within standard PCB tolerance ranges and should not cause compatibility issues. Verify PCB pad spacing during layout review to confirm fit.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All recommended substitute parts—60R050XPR, 72R050XPR, RXEF050-AP, RXEF050S-AP, and PFRA series components—are ROHS3 compliant. All maintain regulatory approvals from cURus, TUV, or equivalent agencies (RXEF series includes additional CQC, CSA, and UL approvals).

Q: What is the inventory status for each substitute?

A: 60R050XPR has 39,280 units in stock (highest availability). RXEF050-AP has 19,239 units. 72R050XPR has 4,987 units. RXEF050S-AP has 4,899 units. PFRA series components range from 751 to 1,685 units depending on variant. Verify current inventory with your supplier before design finalization.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message