Cable Structure:
1. Copper conductor: 7×0.50, 19×0.32, 19×0.41
2. Conductive plastic layer: Ordinary PTC, Flame-retardant PTC, Fluorinated PTC
3. Insulation layer: Modified polyolefin, Flame-retardant polyolefin, Fluorinated polyolefin, Perfluorinated material
4. Shielding layer: Tinned soft round copper wire, braid coverage 80%
5. Jacket layer: Modified polyolefin, Flame-retardant polyolefin, Fluorinated 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, measured with a 2,500VDC megohmmeter for 1 minute, the minimum insulation resistance (between conductor and shield) is 120MΩ.
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
Depending 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 polyolefin base rated at 65°C and those with a fluoropolymer base rated at 110°C and 150°C. The temperature rating here is defined as the maximum ambient temperature at which the heating cable can be effectively applied (MAXIMUM PIPE MAINTENANCE TEMPERATURE). 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 degrade or attenuate cable performance, such as PTC characteristics and heating power, reducing the cable's service life and operational reliability. However, short-term intermittent exposure to temperatures exceeding the rating is permissible. Therefore, in addition to the above temperature ratings, self-regulating heating cables have another temperature rating. For example, for a 65°C rated cable, this temperature 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 the scarcity of relevant literature, many people have a misunderstanding about the temperature rating of self-regulating heating cables, believing it refers to the maximum surface temperature of the heating cable. Thus, claims of 45, 65, 85, and 105°C temperature ratings for polyolefin heating cables have emerged. 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 test ambient temperature and insulation conditions, defining the temperature rating of self-regulating heating cables by surface temperature is unscientific and inaccurate. We need to remember that for polyolefin-based heating cables, the maximum continuous operating temperature should not exceed 65°C.
Classification by Output Power
The output power of a self-regulating heating cable is defined as the power output per unit length of cable at an ambient temperature of 10°C. Classified by heating power output, self-regulating heating cables come in three types: low, medium, and high. Generally, heating cables with power less than 35 W/m are low-power; those with power greater than 35 W/m but less than 70 W/m are medium-power; and those with power greater than 65 W/m are high-power heating cables.
