PFRX.135.2 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The PFRX.135.2 is a polymeric PTC resettable fuse manufactured by SCHURTER Inc., rated for 60V maximum voltage with 1.35A hold current. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing circuit protection applications. The PFRX series has been superseded by active product lines from multiple manufacturers offering identical or compatible electrical characteristics within the polymeric PTC resettable fuse category.

Key Parameters

Parameter	Value
Voltage - Max	60V
Current - Hold (Ih) (Max)	1.35 A
Current - Trip (It)	2.7 A
Current - Max	40 A
Time to Trip	9.6 s
Resistance - Initial (Ri) (Min)	120 mOhms
Resistance - Post Trip (R1) (Max)	300 mOhms
Operating Temperature	-40°C ~ 85°C
Mounting Type	Through Hole
Package / Case	Radial, Disc
Type	Polymeric

Substitute Part Grouping Explanation

Substitution of the PFRX.135.2 is determined by strict electrical and mechanical compatibility. The following parameters must match or remain within acceptable tolerances:

Voltage - Max: 60V (or higher voltage rating acceptable for 60V application)
Current - Hold (Ih) (Max): 1.35 A (exact match required)
Current - Trip (It): 2.7 A (exact match required)
Mounting Type: Through Hole
Package / Case: Radial, Disc
Operating Temperature: -40°C ~ 85°C (minimum requirement)
Resistance - Initial (Ri) and Post Trip (R1): Within specified ranges

Direct equivalents maintain all electrical parameters at 60V. Parts rated for 72V with identical current and trip characteristics are functionally compatible in 60V circuits due to higher voltage margin. Parts with different current ratings (1.6A, 1.85A, 3A, 3.75A) are classified as similar alternatives for applications requiring different hold current specifications.

Parameter Comparison

Part Number	Manufacturer	Voltage - Max	Current - Hold (Ih)	Current - Trip (It)	Time to Trip	Ri (Min)	R1 (Max)	Product Status	Packaging
PFRX.135.2	SCHURTER Inc.	60V	1.35 A	2.7 A	9.6 s	120 mOhms	300 mOhms	Obsolete	-
PFRY.135	SCHURTER Inc.	72V	1.35 A	2.7 A	9.6 s	120 mOhms	300 mOhms	Active	Bulk
PTR060V0135-TR	Eaton - Electronics Division	60V	1.35 A	2.7 A	9.6 s	120 mOhms	300 mOhms	Active	Tape & Reel (TR)
PTR060V0135-TR1	Eaton - Electronics Division	60V	1.35 A	2.7 A	9.6 s	120 mOhms	300 mOhms	Active	Tape & Reel (TR)
RXEF135-2	Littelfuse Inc.	72V	1.35 A	2.7 A	9.6 s	120 mOhms	300 mOhms	Active	Cut Tape (CT)
60R135XMR	Littelfuse	60V	1.35 A	2.7 A	9.6 s	120 mOhms	300 mOhms	Active	Cut Tape (CT)
60R160XMR	Littelfuse Inc.	60V	1.6 A	3.2 A	11.4 s	90 mOhms	220 mOhms	Active	Cut Tape (CT)
60R185XMR	Littelfuse Inc.	60V	1.85 A	3.7 A	12.6 s	80 mOhms	190 mOhms	Active	Cut Tape (CT)
60R300XF	Littelfuse Inc.	60V	3 A	6 A	19.8 s	40 mOhms	100 mOhms	Active	Bulk
60R375XH	Littelfuse Inc.	60V	3.75 A	7.5 A	24 s	30 mOhms	80 mOhms	Active	Bulk
MF-RX135/72-0	Bourns Inc.	72V	1.35 A	2.7 A	9.6 s	120 mOhms	300 mOhms	Active	Bulk

Engineering Selection Recommendations

Direct Equivalents (Identical Electrical Characteristics at 60V):

PTR060V0135-TR and PTR060V0135-TR1 from Eaton are direct replacements for PFRX.135.2. Both maintain 60V maximum voltage, 1.35A hold current, and all thermal and resistance specifications. Both are active products with cURus and TUV certifications. Selection between these two variants depends on packaging requirements: PTR060V0135-TR is available in Tape & Reel format for automated assembly, while PTR060V0135-TR1 offers the same specifications with alternative reel configuration.

60R135XMR from Littelfuse is a direct electrical equivalent at 60V with identical current and trip characteristics. This part carries cURus and TUV approvals and is actively manufactured in Cut Tape packaging.

Voltage-Compatible Alternatives (72V Rating for 60V Application):

PFRY.135 (SCHURTER), RXEF135-2 (Littelfuse PolySwitch®), and MF-RX135/72-0 (Bourns Multifuse®) all maintain identical electrical performance at 1.35A hold current with 72V maximum voltage rating. The higher voltage rating provides additional safety margin in 60V circuits. RXEF135-2 carries the broadest certification scope (CQC, CSA, TUV, UL). MF-RX135/72-0 offers the highest inventory availability (21,965 units).

Current-Variant Alternatives (Different Hold Current Ratings):

60R160XMR, 60R185XMR, 60R300XF, and 60R375XH are suitable only for applications requiring higher hold current thresholds. These parts maintain 60V voltage compatibility but feature increased current ratings (1.6A, 1.85A, 3A, and 3.75A respectively) with proportionally adjusted trip currents. Selection of these variants requires circuit redesign confirmation.

All recommended substitutes comply with RoHS3 and REACH requirements. Operating temperature range (-40°C ~ 85°C) is maintained across all direct equivalents.

Frequently Asked Questions (FAQ)

Q: Can PFRY.135 (72V) be used in place of PFRX.135.2 (60V)?

A: Yes. PFRY.135 maintains identical current hold (1.35A), trip current (2.7A), and resistance specifications. The 72V rating exceeds the 60V requirement, providing additional voltage margin. This substitution is electrically valid for 60V applications.

Q: What is the difference between PTR060V0135-TR and PTR060V0135-TR1?

A: Both are Eaton direct equivalents with identical electrical specifications. The difference is packaging configuration: TR denotes standard Tape & Reel format, while TR1 indicates an alternative reel variant. Electrical performance is identical.

Q: Can 60R160XMR replace PFRX.135.2?

A: No, not as a direct substitute. 60R160XMR has a 1.6A hold current versus 1.35A in PFRX.135.2. This higher threshold changes circuit protection behavior. Use only if circuit design explicitly requires 1.6A hold current.

Q: Which substitute has the best availability?

A: MF-RX135/72-0 from Bourns has the highest inventory (21,965 units). RXEF135-2 from Littelfuse has 3,164 units available. Both are active products with immediate availability.

Q: Are all substitutes RoHS3 compliant?

A: Yes. All listed direct equivalents and alternatives carry RoHS3 Compliant status. All are REACH Unaffected.

Q: What certifications should I verify for my application?

A: Direct equivalents (PTR060V0135-TR, PTR060V0135-TR1, 60R135XMR) carry cURus and TUV certifications. RXEF135-2 carries CQC, CSA, TUV, and UL certifications, providing the broadest regulatory coverage. Verify your application's specific certification requirements before final selection.

Q: Does lead spacing differ between substitutes?

A: Lead spacing varies slightly: PFRX.135.2 and 60R135XMR use 0.201" (5.10mm), while PTR060V0135-TR uses 0.197" (5.00mm), and RXEF135-2 uses 0.199" (5.05mm). These minor variations are within standard PCB tolerance for radial through-hole components. Verify PCB pad spacing before assembly.

Q: Can I mix different manufacturers in the same circuit?

A: Yes. All direct equivalents maintain identical electrical specifications and certifications. Mixing SCHURTER, Eaton, Littelfuse, and Bourns parts in the same circuit is electrically valid. Verify procurement and supply chain requirements for your application.

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