Large Stock — Application Assistance — 50 Years Experience

• SELF-REGULATING — Freeze Protection up to 250°F
• CONSTANT WATTAGE — Up to 500°F
• MINERAL INSULATED — Up to 1000°F
• Full coverage Pipe Heating Systems — Standard Freeze Protection Specials up to 160°F
• IMPEDANCE HEATING — Up to 1000°F High Temperature Applications

Calculate Heat Requirements for Maintaining A Pipe Temp on the Web:
www.thermalinc.com/math/pipetrace.htm

Advantages:

• Cut to fit in the field
• Possible lower operating cost
• Possible lower installation cost
• Wide variety of wattages
• Most tolerant to overlapping
• Low Cost

Disadvantages:

• High start-up currents
• Difficult to precisely control temperature
• Not well suited for process control
• Low design temperatures

Self-regulating cable has two parallel conductors or bus wires extruded in a polymer core. The core's resistance changes proportionally with temperature.

The key to understanding Self-regulating cable is the output adjusts proportionally to the cable sheath temperature not the temperature of the pipe heated.

There is no direct feedback for the pipe temperature. Most self-regulating cables are designed to give their rated wattage at 50 degrees F. The wattage output will exceed the rated wattage when the cable temperature is below 50 degrees, and the lower the cable temperature the larger this wattage (i.e. amperage) is. INRUSH! A high start up current is the result. Tight temperature control is also more difficult with self-regulating cable, because the wattage output is always changing, seeking 50 degrees F on the cable, not the pipe or fluid in the pipe.

Self-regulating cable works quite well for freeze protection applications. Freeze protection and low temperature applications that do not require very tight control. The inrush can be considered on the design of wiring and breakers, and there are some other cost savings to consider. We always recommend a thermostat on every cable we sell. However, when there are several very short runs or several pipe size changes, one ambient thermostat can save on a job.

Visit our Math Page to: Calculate Heat Requirements for Maintaining Pipe Temp
www.thermalinc.com/math/pipetrace.htm

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Advantages:

• Cut to fit in the field
• Easily controlled
• Built in cold length at every power connection
• Wide variety of wattage outputs
• Low cost
• 480 Volt Cable available
• Design Temperatures up to 500°F

Disadvantages:

• Requires pipe sensing thermostats
• Can NOT be overlapped

Constant Wattage Cable is made up with two parallel conductors or wires. These wires have a heater wire wrapped around and connected in approximately 2-foot intervals in parallel. This design provides constant wattage output or a uniform output all along its length. The heater wires are designed such that if any section of cable should fail, the rest of the heater would continue to operate without change.

Constant wattage cable should NOT be overlapped. The effect of double the wattage where the cable crosses will cause high temp failures.

The constant wattage output makes maintaining higher and more accurate process temperatures easier. This cable is well suited for freeze protection and many low temp process control applications.

This cable can be cut in the field. When terminated the last 2-foot heater section becomes a cold section "unheated." This provides an unheated section of cable to penetrate the insulation, enter the junction box and make up power connections. Constant Wattage Cable needs a thermostat on each pipe and each pipe size in order to maintain accurate temperature control.

Visit our Math Page to: Calculate Heat Requirements for Maintaining Pipe Temp
www.thermalinc.com/math/pipetrace.htm

Call us at (901) 452-4516 or e-mail us at thermalinc@thermalinc.com