1. Rating


2. Cautions to be observed when designing for use of TR

(1) Do not install TR where it may be subjected to severe or continuous vibration.

(2) For sealing-in with impregnating fluids or use of cleaning solvents, investigation (trial tests) with prototypes and initial products is required to ensure that intended sealing or cleaning does not affect marking and function of the TR for each individual application.


3. Cautions to be observed when Handling TR

(1) When bending terminal, hold between TR body and bend, and bend slowly. Do not bend terminal within 3mm from body. Never bend terminal when TR is hot.


4. Cautions to be observed when installing TR

(1) When TR is installed by spot welding, the condition of spot welding needs to be verified to make sure that the fusible element is not damaged or TR shall not function by the heat from spot welding.

(2) Installation by soldering is not recommended due to the high possibility of the function of TR and/or damage on its fusible element.

(3) When TR’s internal material is found on the surface after installation, replace it with new one even if the resistance value may be normal.

(4) When TR is installed by spot welding, measure the electric resistance of the welded point by a low– ohmmeter. Make sure that electric resistance is low and welded condition is appropriate. In case that electric resistance is high, it may result in malfunction of TR, or the temperature of TR may exceed the maximum allowable temperature. In addition, verify the mechanical strength of welded point by sampling inspection.


5. Repair and replacement

(1) TR is not repairable. TR small in size and not intended to be replaced.

(2) Replacement of TR is not recommended, because, insulation characteristics and other safety characteristics of the equipment may have been affected by the excessive heat. Replacement of functioned TR must be made by the customer’s risk ensuring following conditions.

(a) Replace with the same manufacturer’s same thermoprotector having the same Type No.

(b) Install the TR in exactly the same way.

(c) The cause/reason of the TR function is cleared completely.

(d) Insulation characteristics and other safety characteristics of the equipment are not decreased.


6. Resistance to tracking and further information.

Please feel free to contact our sales department for further information including Resistance tracking.


7. Interrupting current (Ib)

1.5 times rated current (Ir)


8. Transient overload current (Ip)

15 times rated current (Ir)



Uchihashi Estec Co., Ltd.  2010-06