RLD60P050XF Equivalent & Substitute Parts

Part Overview

The RLD60P050XF 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 part is currently obsolete, making equivalent and substitute components necessary for ongoing system support and new designs requiring similar electrical protection characteristics.

Key Parameters

Parameter	Value
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)
Lead Spacing	0.201" (5.10mm)

Substitute Part Grouping Explanation

Substitution eligibility for the RLD60P050XF is determined by the following critical parameters:

Voltage Rating: Maximum voltage must be equal to or greater than 60V
Current - Hold (Ih): Must be 500 mA maximum
Current - Trip (It): Must be 1 A
Mounting Type: Through Hole radial configuration required
Package / Case: Radial, Disc format
Operating Temperature Range: -40°C to 85°C minimum
Resistance Characteristics: Initial resistance (Ri) and post-trip resistance (R1) within specified ranges

Substitute parts are grouped into three categories:

Direct Voltage Equivalents (60V): Parts maintaining the original 60V rating with identical electrical characteristics
Higher Voltage Equivalents (72V): Parts with elevated voltage ratings suitable for applications with higher voltage headroom
Cross-Manufacturer Equivalents: Alternative manufacturer components meeting identical electrical and mechanical specifications

Parameter Comparison

Parameter	RLD60P050XF	60R050XU	60R050XPR	72R050XPR	RXEF050-AP	RXEF050S-AP	MF-R050
Manufacturer	Littelfuse Inc.	Littelfuse Inc.	Littelfuse Inc.	Littelfuse Inc.	Littelfuse	Littelfuse	Bourns Inc.
Series	POLY-FUSE® RLD60	POLY-FUSE® 60R	POLY-FUSE® 60R	POLY-FUSE® 72R	PolySwitch® RXEF	PolySwitch® RXEF	Multifuse® MF-R
Product Status	Obsolete	Active	Active	Active	Active	Active	Active
Voltage - Max	60V	60V	60V	72V	72V	72V	60V
Current - Hold (Ih) (Max)	500 mA	500 mA	500 mA	500 mA	500 mA	500 mA	500 mA
Current - Trip (It)	1 A	1 A	1 A	1 A	1 A	1 A	1 A
Current - Max	40 A	40 A	40 A	40 A	40 A	40 A	40 A
Time to Trip	4 s	4 s	4 s	4 s	4 s	4 s	4 s
Resistance - Initial (Ri) (Min)	500 mOhms	500 mOhms	500 mOhms	500 mOhms	500 mOhms	500 mOhms	410 mOhms
Resistance - Post Trip (R1) (Max)	1.17 Ohms	1.17 Ohms	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	-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	0.311" 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 0.122" 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)	0.311" Dia x 0.122" T (7.90mm x 3.10mm)
Lead Spacing	0.201" (5.10mm)	0.201" (5.10mm)	0.201" (5.10mm)	0.201" (5.10mm)	0.199" (5.05mm)	0.199" (5.05mm)	0.201" (5.10mm)
RoHS Status	RoHS non-compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Approval Agency	cURus, TUV	cURus, TUV	cURus, TUV	cURus, TUV	CQC, CSA, TUV, UL	CQC, CSA, TUV, UL	cURus, TUV

Engineering Selection Recommendations

Primary Substitutes (Littelfuse POLY-FUSE® 60R Series)

The 60R050XU and 60R050XPR are direct replacements for the obsolete RLD60P050XF. Both maintain the original 60V voltage rating and identical electrical characteristics. The 60R050XPR is available in Cut Tape packaging with higher inventory (39,280 pcs), while 60R050XU is supplied in Bulk packaging (4,700 pcs). Both parts are Active status with ROHS3 compliance and expanded approval certifications (cURus, TUV). These components are recommended for applications requiring exact voltage and current specifications matching the original design.

Higher Voltage Alternative (Littelfuse POLY-FUSE® 72R Series)

The 72R050XPR provides a 72V maximum voltage rating while maintaining all other electrical parameters identical to the RLD60P050XF. This part is suitable for applications where increased voltage headroom is beneficial or where system voltage may exceed 60V. The 72V rating does not compromise performance in 60V applications. ROHS3 compliance and cURus/TUV certifications are provided.

PolySwitch® RXEF Series (Littelfuse)

The RXEF050-AP and RXEF050S-AP are functionally equivalent at 72V rating with identical electrical characteristics. These parts feature expanded approval certifications including CQC, CSA, TUV, and UL. Mechanical dimensions show minor thickness variation (0.118" vs. 0.122") and lead spacing difference (0.199" vs. 0.201"), which remain within standard PCB tolerance ranges for radial through-hole components. Both parts are Active status with ROHS3 compliance and MSL 1 rating.

Cross-Manufacturer Alternative (Bourns Multifuse® MF-R050)

The MF-R050 from Bourns Inc. provides electrical equivalence at 60V with identical hold current, trip current, and time-to-trip specifications. Initial resistance is specified at 410 mOhms minimum (versus 500 mOhms for Littelfuse parts), which represents a lower resistance baseline. Mechanical form factor, mounting type, and operating temperature range are identical. ROHS3 compliance and cURus/TUV certifications are provided. This part is suitable for applications where cross-manufacturer qualification is acceptable.

Frequently Asked Questions (FAQ)

Q: Can I use the 72V-rated parts (72R050XPR, RXEF050-AP, RXEF050S-AP) as direct replacements in a 60V circuit?

A: Yes. The 72V maximum voltage rating indicates the component can safely operate at voltages up to 72V. In a 60V circuit, the part operates well within its voltage specification. All other electrical parameters (hold current, trip current, time to trip, resistance characteristics) remain identical to the original RLD60P050XF.

Q: What is the significance of the thickness difference between RLD60P050XF (0.122") and RXEF050-AP/RXEF050S-AP (0.118")?

A: The thickness difference of 0.004" (0.10mm) is within standard PCB tolerance ranges for radial through-hole component placement. Both parts maintain the same lead spacing (5.10mm vs. 5.05mm nominal) and diameter (0.311"), ensuring compatibility with standard PCB footprints designed for radial disc fuses.

Q: Why does the MF-R050 have a lower initial resistance specification (410 mOhms vs. 500 mOhms)?

A: The MF-R050 specifies a minimum initial resistance of 410 mOhms, while the RLD60P050XF specifies 500 mOhms minimum. This represents a lower baseline resistance in the Bourns component. Both parts meet the maximum post-trip resistance specification of 1.17 Ohms. Applications sensitive to initial resistance characteristics should evaluate this parameter during qualification.

Q: Are all substitute parts RoHS compliant?

A: The original RLD60P050XF is RoHS non-compliant. All substitute parts listed (60R050XU, 60R050XPR, 72R050XPR, RXEF050-AP, RXEF050S-AP, MF-R050) are ROHS3 compliant, meeting current environmental regulations for new designs and manufacturing.

Q: What packaging options are available for the substitute parts?

A: Littelfuse 60R050XU is supplied in Bulk packaging. Littelfuse 60R050XPR, 72R050XPR, and Littelfuse RXEF series (RXEF050-AP, RXEF050S-AP) are supplied in Cut Tape (CT) packaging. Bourns MF-R050 is supplied in Bulk packaging. Cut Tape packaging is suitable for automated assembly processes, while Bulk packaging is appropriate for manual assembly or reel-based operations.

Q: Which substitute part has the highest inventory availability?

A: The 60R050XPR has the highest inventory with 39,280 pcs in stock, followed by RXEF050-AP with 19,239 pcs. Both parts are suitable for high-volume production requirements.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message