Over-temperature protection
Thermal & Temperature Fuses
One-shot thermal cutoffs (TCO) that open at a fixed temperature, plus resettable PPTC / polyfuse devices for board-level over-current — built and tested in our own factory.
- Last-line over-temperature safety for appliances
- Functioning temperatures across the working range
- Built to IEC 60691 and UL 60691
- One-shot TCO and resettable PPTC from one supplier
CEULRoHSREACH
Product range
A complete range from one supplier
Every line below is engineered, built and tested in our own factory — so you can source a complete, matched range from a single manufacturer, with one set of documents.
Thermal Cutoffs (TCO)
One-shot devices that open the circuit at a fixed temperature — a definite over-temperature safeguard.
One-shotTf rangeAxial / radial / tab
View range
Resettable Fuses (PPTC)
Polyfuse devices that limit over-current and auto-reset once they cool — for board-level protection.
ResettablePCB / SMDUSB & ports
View rangeSpecifications & standards
Built and tested to standard
The headline ratings and the standards we build to. Full datasheets — with tolerances, time-current curves and dimensions — are available on request.
| Type | One-shot TCO · resettable PPTC |
|---|---|
| Responds to | Temperature (TCO) · current (PPTC) |
| Functioning temp. | Specified per device (Tf) |
| Standards | IEC 60691 · UL 60691 · IEC 60730 |
| Mounting | Axial · radial · tab · SMD |
| Reset | TCO: one-shot · PPTC: auto-reset |
Standards & approvals
- IEC 60691 Thermal-links — requirements and application guide
- UL 60691 Thermal-links — North America
- IEC 60730 / UL 1434 Resettable PPTC / thermistor devices
Choose a thermal cutoff's functioning temperature (Tf) above the circuit's normal maximum operating temperature but below its hazard temperature — so it rides through normal heat and trips before damage. Too low nuisance-trips; too high leaves no protection.
Complete guide to fuse typesA thermal fuse is the safeguard that acts when a current fuse can’t see the problem. A current fuse responds to amps; a thermal cutoff responds to heat, opening the circuit before an overheating motor, transformer or heater becomes a hazard — regardless of how much current is flowing. That’s why appliance safety approvals so often require one. Tenso manufactures one-shot thermal cutoffs across the functioning-temperature range, plus resettable PPTC devices for boards.
Choose the right functioning temperature (Tf)
A thermal cutoff is specified by the temperature at which it opens. Choose a Tf above the circuit’s normal maximum operating temperature but below its hazard temperature, so the device rides through normal heat and trips before damage. Too low and it nuisance-trips; too high and it leaves no protection. Tell us the appliance’s normal and hazard temperatures and we’ll help select the Tf.
One-shot (TCO) vs resettable (PPTC)
A thermal cutoff is one-shot: once it trips it stays open and must be replaced — exactly what you want for a definite safety disconnection. A PPTC (“polyfuse”) limits the current and resets when it cools — exactly what you want for nuisance over-currents or sealed, inaccessible boards. Choose by whether you need a permanent disconnection or an auto-resetting limit.
Often used alongside a current fuse
Many appliances use both: a current fuse for electrical faults and a thermal fuse for thermal runaway. Tell us the design and we’ll spec the pair.
Why source from Tenso
You're buying from the factory
No trading-company markup and no telephone game with a sub-supplier — design, tooling, production and QC all sit under one roof.
Over-temperature expertise
Help choosing the right functioning temperature (Tf) for your appliance's normal and hazard temperatures.
One-shot and resettable
One-shot TCO for a definite safety disconnection; resettable PPTC for nuisance over-currents or sealed boards — both from one supplier.
Approval-driven
Built to IEC 60691 / UL 60691 — and appliance safety approvals often require a thermal cutoff.
OEM & volume
High-volume supply with private-label options for appliance and electronics builds.
Applications
Where these parts go to work
Household appliances
Hair dryers, heaters, coffee makers
Transformers & motors
Thermal-runaway safeguard
Battery packs & chargers
Over-temperature & over-current
Board electronics
Resettable PPTC, USB & ports
Certified
Compliance you can hand to your QA team
Built to the standards your market and your auditors expect — with certificates and declarations available on request.
Conformity for the European market across applicable ranges.
UL recognition/listing on qualifying thermal devices.
Restricted-substance compliance for electronics supply chains.
Substance-of-concern declarations available on request.
Cross-reference
Switching from another brand?
Second-sourcing a thermal cutoff by its functioning temperature? Send the Tf and form factor and we'll confirm the Tenso equivalent.
| Type | Spec | Tenso equivalent | Reset |
|---|---|---|---|
| Thermal cutoff (TCO) | Tf by °C | TT-TCO series | One-shot |
| Radial-lead TCO | Tf by °C | TT-RTCO series | One-shot |
| PPTC / polyfuse | Hold/trip current | TT-PPTC series | Auto-reset |
How to order
From enquiry to delivery
- 01
Enquiry
Send the functioning temperature, current, voltage and form factor. We confirm fit and Tf selection.
- 02
Samples
Approve samples for qualification against your appliance or board.
- 03
Quote & terms
Pricing, MOQ, lead time and Incoterms in one clear quote.
- 04
Production
Manufactured and assembled in-house to the approved sample.
- 05
QC & shipping
Batch-inspected, then packed and shipped with documentation to your port.
Request a quote
Tell us what you need protected.
Send a part number, a drawing, or a description of the circuit. We confirm fit and pricing within one business day.
- Email sales@tensofuse.com
- WhatsApp Chat with sales
FAQ
Over-temperature protection — questions buyers ask
What is a thermal fuse / thermal cutoff?
A one-shot safety device that opens the circuit when its body reaches a fixed temperature, protecting against overheating regardless of current.
What temperature thermal fuse do I need?
One whose functioning temperature (Tf) sits above the circuit's normal maximum operating temperature but below its hazard temperature — match it to the appliance's thermal profile.
Thermal fuse vs regular fuse — what's the difference?
A thermal fuse responds to temperature; a regular (current) fuse responds to current. They guard against different faults and are often used together.
Can a thermal fuse be reset?
No — a thermal cutoff is one-shot and must be replaced once it operates. The resettable equivalent is a PPTC ('polyfuse').
What does TCO mean?
Thermal cut-off — another name for a one-shot thermal fuse.