Cable Structure:
1. Copper conductor: 7×0.50, 19×0.32, 19×0.41
2. Conductive plastic layer: Ordinary PTC, Flame-retardant PTC, Fluorine-containing PTC
3. Insulation layer: Modified polyolefin, Flame-retardant polyolefin, Fluorine-containing polyolefin, Perfluorinated material
4. Shielding layer: Tinned soft round copper wire, braid coverage 80%
5. Jacket layer: Modified polyolefin, Flame-retardant polyolefin, Fluorine-containing polyolefin, Perfluorinated material
3. Installation temperature: Minimum: -5°C
4. Thermal stability: After 300 cycles between 15°C and 99°C, the cable heat output remains above 90%.
5. Bending radius: 25.4mm at 20°C room temperature; 35.0mm at -30°C low temperature
6. Insulation resistance: For a cable length of 100m at an ambient temperature of 75°C, when tested with a 2,500 VDC megohmmeter for 1 minute, the minimum insulation resistance (between conductor and shield) is 120 MΩ.
7. Starting current (10°C): 0.4A per meter
8. For installation and use, please refer to the precautions section
9. Maximum use length: not exceeding 100 meters
Structure Classification:
Classification by Temperature
Based on the composition of the polymer PTC material, self-regulating heating cables are divided into low-temperature and high-temperature types.
Common types on the market include heating cables with a temperature rating of 65°C based on polyolefin, and 110°C and 150°C heating cables based on fluorinated materials. The temperature rating here is defined as the maximum ambient temperature (MAXIMUM PIPE MAINTENANCE TEMPERATURE) at which the heating cable can be effectively applied. It can also be understood as the highest ambient temperature at which the cable can operate stably for a long time and produce effective heating power output. Exceeding the specified temperature rating, on one hand, due to increased resistance, the cable's output power becomes very small, resulting in low actual heating efficiency. On the other hand, prolonged use at overtemperature can cause cable performance, such as PTC characteristics and heating power, to degrade or attenuate, reducing the cable's service life and operational reliability. However, short-term intermittent exposure to temperatures exceeding the rated temperature is permissible. Therefore, in addition to the above temperature ratings, self-regulating heating cables have another temperature rating. For example, for a cable with a 65°C temperature rating, this rating is 85°C; for a 110°C rated cable, it is 130°C; and for a 150°C cable, it is 230°C. However, at this point, the effective output power of the cable is close to zero.
Due to limited relevant literature, many people have a misunderstanding of the temperature rating of self-regulating heating cables, believing it refers to the maximum surface temperature of the heating cable. Hence, there are claims of 45, 65, 85, and 105°C temperature-rated polyolefin heating cables. In reality, because the cable's output power is related to the ambient temperature, and the cable's surface temperature is closely linked to the ambient temperature during testing and the insulation condition, it is unscientific and inaccurate to define the temperature rating of self-regulating heating cables by surface temperature. We need to remember that for heating cables based on polyolefin, the maximum continuous operating temperature should not exceed 65°C.
Classification by Output Power
The output power of a self-regulating heating cable refers to the power output per unit length of cable at an ambient temperature of 10°C. According to the heating power output classification, self-regulating heating cables are divided into three types: low, medium, and high. Generally, heating cables with a power output less than 35 W/m are low-power heating cables; those with a power output greater than 35 W/m but less than 70 W/m are medium-power heating cables; and those with a power output greater than 65 W/m are high-power heating cables.
