Xiamen SET Electronics Co., Ltd.
SETsafe | SETfuse Thermal-link & Fusing Resistor (TRXF) is an active protection integrated component with Over Temp. and Over Current Protections, in which Alloy Thermal-Link (ATCO) is built in the core of Fusible Wirewound Resistor (RXF) and forming special connection with RXF. It is not only able to proceed over temp. protection by ATCO itself but also proceed over current protection by RXF transferring heat to ATCO to open the circuit.

RXF
Fusible Wirewound Resistor
A power resistor which is made by winding a resistive element on a ceramic core, and the core is coated by insulation coating. It intends to interrupt a current flow at a predetermined time when the current exceeds a predetermined value. Fusible Wirewound Resistor is disposable fuse elements and is non-recoverable.
— (SETsafe | SETfuse Standards)
ATCO
Alloy Thermal-Link
Alloy Type Thermal-Link, Alloy is the thermal element.
— (GB/T 9816.3)
R
Rated Resistance
Resistance value for which the resistor has been designed, and which is generally used for denomination of the resistor.
— (IEC 60115-1)
P0
Actual Power
The Max. power of TRXF can be used within the allowable operating Temp. range.
— (SETsafe | SETfuse Standards)
UN
Rated Voltage
The d.c. or a.c. r.m.s. voltage calculated from the square root of the product of the rated resistance and the rated dissipation.
— (IEC 60115-1)
Tf
Rated Functioning Temp.
The temperature of the Alloy Thermal-Link which causes it to change the state of conductivity with a detection current up to 10 mA as the only load.
— (IEC 60691)
Tolerance: Tf °C (GB/T 9816, EN 60691, K60691).
Tolerance: Tf ± 7 °C (J60691).
Fusing Temp.
The temperature of the Alloy Thermal-Link which causes it to change its state of conductivity is measured with silicone oil bath in which the temperature is increased at the rate of 0.5 °C to 1 °C / minute, with a detection current up to 10 mA as the only load.
— (IEC 60691)
Th
Holding Temp.
The maximum temp. at which a Thermal-link(TCO) will not change its state of conductivity when conducting rated current for 168 h.
— (IEC 60691)
TCR
Temp. Coefficient of Resistance
Relative variation of resistance between two given temp. divided by the difference in the temp. producing it.
— (IEC 60115-1)

SETsafe | SETfuse Quality Policy
Provide Industry-Leading Products
Raw-materials Supplier
Select critical raw materials: Must be from a manufacturer with quality management system (ISO9001, IATF16949) certification.
Annual or Quarterly Audits.
IQC (Incoming Quality Check)
AQL(MIL-STD-105E), Dimensions, Function, Visual Inspection, RoHS & REACH Test.
Document
Formulate corresponding incoming inspection specifications (01-QA-06-xxx) for each key material according to design data such as material technical indicators.
Testing Equipment and Tools
Projector, Resistance meter, Tool Microscope, Salt Spray Tester, Universal Material Testing Machine, Spectrum Analyzer, etc.

Manufacturing Process
Online Inspection and Testing (Function 100% Automatic Testing).
Document
Process Flow Chart.
Failure Mode and Effects Analysis (FMEA).
Quality Control Flow Chart (QCFC).
Standard Inspection Procedure (SIP).
Work Instruction (WI).
Online Testing and Inspection
Resistance test system (100% Automatic Testing).
100% Visual Inspection.
etc.

IPQC (In Process Quality Control) Inspection
AQL(MIL-STD-105E), Dimensions Inspection, Function Test, Visual Inspection.
FQC ( Final Quality Control)
AQL(MIL-STD-105E), Dimensions Inspection, Function Test, Visual Inspection, RoHS & REACH Test.
Reliability Test
T Test specification (01-TE-01-3003-001)
Including 26 items of Appearance Requirements, Electrical Performance, Mechanical Performance, Soldering Performance, Environmental Test and Life Test. e.g.
Insulation Resistance Test.
Temperature Cycle Test.
Functioning Temperature Test.
Surge Test.
etc.
OQC (Outgoing Quality Control)
AQL(MIL-STD-105E), Packaging, Labeling, Quantity Inspection.
Agency
Agency (Safety Certificate) Annual, Quarterly Audits.
Management System
ISO9001, (TUV approved and issued certificate).
ISO14001, ISO45001, etc.
Click to view the certificate
Environmental
RoHS & REACH Compliant.
SETsafe | SETfuse

Cold Resistance Test
1. If product TCR is not less than 350 (10-6/°C), the measured resistance value shall be corrected as the relative resistance value under 25 °C according to TCR formula.
2. Resistance Measurement (4-terminal test)
Replacement
As TRXF is a non-resettable product, for safety sake, please use the same type of TRXF for replacement.
Usage
1. Do not touch the resistor body or pins directly when power is on, to avoid burn or electric shock.
2. When air pressure is from 80 kPa to 106 kPa, the relative altitude shall be +2000 m to - 500 m.
Storage
1. Please store TRXF with ambient temp. 10 °C ~ 30 °C and relative humidity 30% ~ 75%.
2. Do not store the TRXF at the high temperature, high humidity or corrosive gas environment, avoid influencing the solderability of the pins, please use them up within 1 year after receiving the goods.
Soldering Parameters
Wave Soldering Parameters (For Reference Only)
The Wave Soldering Parameters are for reference only, before TRXF is for practice usage, relative validation is recommended.

Recommended Hand-Soldering Parameters
Solder Iron Temp.: | (350 ± 5) °C |
Soldering Time: | 2 s Max. (115 °C ≤ Tf ≤ 150 °C) |