Xiamen SET Electronics Co., Ltd.
Thermally Protected Resistor (TPR) is an unique type of Power Resistor, with Over Temp. and Over Current Protections. Thermally Protected Resistor (TPR) is a type of power resistor, where Alloy Thermal-Link (ATCO) and Fusible Wirewound Resistor (RXF) are in series encapsulated in a ceramic case with silicone cement.
SETsafe | SETfuse TPR has the same physical size as ordinary ceramic resistor while additionally providing fault current protection. TPR can also effectively protect against the damages to devices & equipment, caused by continuous heat dissipations by ceramic resistors due to fault currents.
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)
Alloy Type Thermal-Link, alloy is the thermal element. Thermal-Link is A non-resettable device incorporating a THERMAL ELEMENT which will open a circuit once only when exposed for a sufficient length of time to a temp. in excess of that for which it has been designed.
Resistance value for which the resistor has been designed, and which is generally used for denomination of the resistor.
— (IEC 60115-1)
The Max. power of TRXF can be used within the allowable operating Temp. range.
— (SETsafe | SETfuse Standards)
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)
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).
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.
SETsafe | SETfuse Quality Policy
Provide Industry-Leading Products
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.
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.
Process Flow Chart.
Failure Mode and Effects Analysis (FMEA).
Quality Control Flow Chart (QCFC).
Standard Inspection Procedure (SIP).
Work Instruction (WI).
100% Visual inspection.
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.
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.
OQC (Outgoing Quality Control)
AQL(MIL-STD-105E), Packaging, Labeling, Quantity Inspection.
Agency (Safety Certificate) Annual, Quarterly Audits.
ISO9001, (TUV approved and issued certificate).
ISO14001, ISO45001, etc.
Click to view the certificate
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).
As TPR is a non-resettable product, for safety sake, please use the same type of TPR for replacement.
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.
1. Please store TPR with ambient temp. 10 °C to 30 °C and relative humidity 30% to 75%.
2. Do not store the TPR 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.
Recommended Hand-Soldering Parameters
Solder Iron Temp.:
(350 ± 5) °C
3 s Max. (115 °C ≤ Tf ≤ 150 °C)
5 s Max. (Tf > 150 °C)
Thermally Protected Resistor (TPR) Catalog