Read this instruction before you design an application or install a temperature fuse. The purpose of this instruction is to reduce the risk of abnormal temperature fuses due to incorrect design, installation methods and hazardous working conditions in applications.

● Each temperature fuse has its rated electrical and temperature parameters, the application should make it work in the specified rated parameter range. These parameters include TF (rated operating temperature), TH or TC (holding temperature), TM (limit temperature) and rated current and voltage. For details, see the parameters of each model in Temperature Fuse Technical Parameter Table.

● The installation design should pay attention to the temperature fuse long-term continuous working environment temperature do not exceed their holding temperature.

● Temperature fuse is a non-resettable device, for safety, in the replacement of temperature fuse please choose the same model of temperature fuse, installed in the same position.

● In the design of application products pay attention to let the temperature fuse only feel the required heat source. For example, in the case of the heater, the temperature fuse cannot be directly connected with the electric heating wire, but must be isolated from the hot wire through a non-heating wire, so that the heat of the electric heating wire will not pass into the temperature fuse through the pin to accelerate its action; As in the case of a transformer or motor, the temperature should be controlled within the coil, so that the temperature fuse has good heat conduction with the coil.

● The application product must be tested to ensure that the temperature around the fuse does not exceed its limit temperature (TM) when any abnormal condition occurs. This condition may occur in a condition called "residual heat overflush". For example: A hot fan causes the temperature to rise to TF when the air inlet or outlet is blocked, and then the temperature fuse breaks the circuit. However, an incorrect design may cause the device to open in advance and excessive waste heat overshoot may damage the fuse. The applied product shall be tested to ensure that the temperature around the temperature fuse does not reach TM during the on-off cycle of the temperature controller under normal temperature fluctuations, such as heater temperature fluctuations caused by controller action and reset

● In the design, it is recommended to use a model equipped with thermocouple temperature fuse to select and determine the appropriate temperature rating specifications and installation position.

● Do not install temperature fuses in places of severe vibration.

● The temperature fuse can be connected by solder welding, spot welding and hinge.

● When bending the pin, it must be operated with a tool to ensure that the pin bending has enough arc. The pin cannot be bent within 3mm from the root, and the shell and sealing resin cannot be clamped by the tool during bending

The pin shall not be damaged, notched, bent at a sharp Angle or burned during installation.

● Sealing resin and shell shall not be damaged, burned or overheated.

● Non-torsional temperature fuse (e.g., pin rotation relative to housing).

● Avoid applying an angled force on the pin (such as pushing or pulling the pin at an Angle relative to the outer shell), which will damage the sealing resin.

● When fixing the temperature fuse, do not apply too much pressure on the shell, sealing resin or pin (such as pulling the fuse, clamping too much or strapping too tightly), which will cause damage to the fuse or cause stress concentration on the pin.

● The connecting lead should have enough remaining length and soft enough, temperature fuse and knot point should be fixed, in order to avoid in normal use of vibration caused by loose hinge point.

● The axial force (pull or thrust) applied on the pin must not exceed the specified test "pull" or "thrust", the other block type series fuse, the maximum test pull is 1 lb, the maximum test thrust is 0.4 lb (at room temperature), must be done first sample test to determine in the production process will not exceed the maximum test "pull" and "thrust" on the pin.

● When designing applications, stress caused by contraction, expansion and other movement of component materials in contact with the pins and housing must be considered. Soft, flexible or cold, low resistance leads should be used to connect with the temperature fuse.

● Contact resistance must be controlled to ensure the lowest resistance, inappropriate connection will lead to fuse action in advance, contact must be sampled to ensure that the connection has the appropriate mechanical connection strength, inappropriate connection will lead to contact resistance increase and then produce high temperature at the contact, causing damage to sealing resin and other components, which may make the device short circuit or other failures.

● When using solder can spot welding, attention must be paid to avoid welding overheating damage temperature fuse. Table 1 is the maximum welding time guide (single foot, foot length 10mm, at 300 degrees Celsius)

Rated operating temperature TF Welding time (seconds)

102-115 ℃

1

125-139 ℃

2

150 ℃

3

Because the temperature sensing element inside the temperature fuse is a section of low melting point alloy wire, connected to the two pins, improper welding operation (welding temperature is too high, welding time is too long, the pin is too short, etc.) will make the heat through the pin into the temperature fuse, the temperature sensing element overheating damage (fusing, or the end of the thermal impact becomes thin, thus becoming fragile, and the reliability of the connection with the pin decreases. When the use of current through or other reasons, the damaged parts may produce early fracture phenomenon.

Avoid welding overheating damage temperature fuse method:

Use longer pins where possible, longer pins allow longer welding times and reduce the possibility of overheating. Figure 3 shows an example of how to keep a longer pin in a smaller position. In the case of short pins, needle-nose pliers or other tools should be used to clamp the position between the solder joint and the fuse body on the pin during welding to dissipate heat, so as to avoid the amount of welding into the internal temperature of the fuse. At the same time, the welding temperature should not be too high, and the welding time should be as short as possible.

● When soldering or spot welding, the pin must be properly secured, otherwise the pin or sealing resin may be damaged. When the sealing resin is hot, pulling or twisting the pin may detangle it from the fuse, causing mechanical failure. Therefore, do not move the fuse before the sealing resin cools. Weld, wrap, fix or move the temperature fuse again at least 30 seconds apart. The cooling time depends on the welding temperature, welding (or spot welding) time, lead length, etc. It is recommended to test first to determine the best welding (spot welding) time, temperature and cooling tool.

● The current cannot flow through the temperature sensing alloy when spot welding.

● Mechanical connection can not rely on brazing alone.

● Incoming goods must be inspected to see if there is damage in the process of transportation. It is recommended to inspect again after installation. It is recommended to conduct conductive measurement or X-ray inspection before and after installation.

● Prototype sample or early production sampling and experimental assembly test products must be tested, in normal work and abnormal state to measure the temperature of the product and the temperature of the key parts, after the test must be checked temperature fuse products.