Tuesday, December 15, 2015

Self Regulating Heating Cable

Self regulating heating cable
Self regulating heating cable
Self-regulating heating cables automatically adjust their power output to compensate for temperature changes. The outer jacket, braid, and inner jacket provide mechanical, chemical, and electrical protection. The magic happens in the conductive core that surrounds the two parallel conductors. As the ambient temperature drops, the core contracts microscopically, and the number of electrical paths through the core increases, more heat is produced. Conversely, as the ambient temperature rises, the core expands and has fewer electrical paths, and less heat is produced. At a certain temperature, almost all the electrical paths are disrupted and power output is close to zero. A self-regulating heating cable adjusts its power output along its entire length. That's what makes it a safe and reliable solution for many applications.

Self-regulating cable is flexible, and is much easier than constant wattage cable because it can be cut-to-length in the field, terminated, and (if needed) overlapped without fear of burnout. This is very valuable in areas where complex piping systems exist with many valves, tanks and vessels.

As with any heat tracing cable, proper wattage requirements need to be calculated. In order to properly calculate wattage, the following information must be known:
  • Pipe size and material
  • Insulation type and thickness
  • Maintain temperature
  • Minimum ambient temperature
  • Minimum start-up temperature
  • Service voltage
  • Chemical environment
  • Maximum intermittent exposure temperature
  • Electrical area classification
Once this information is known, most manufacturers will have wattage calculators where you can simply use the above data to calculate your requirements.