Power Supply and Control
Trace heat cables may be connected to single-phase or (in groups) to three-phase power supplies. Power is controlled either by a contactor or a solid-state controller. For self-regulating cable, the supply must furnish a large warm-up current if the system is switched on from a cold starting condition. The contactor or controller may include a thermostat if accurate temperature maintenance is required, or may just shut off a freeze-protection system in mild weather.
Electrical heat tracing systems may be required to have earth leakage (ground fault or RCD) devices for personnel and equipment protection. The system design must minimize leakage current to prevent nuisance tripping; this may limit the length of any individual heating circuit.
Read more about this topic: Trace Heating
Famous quotes containing the words power, supply and/or control:
“There is assuredly no more effectual method of clearing up one’s own mind on any subject than by talking it over, so to speak, with men of real power and grasp, who have considered it from a totally different point of view.”
—Thomas Henry Huxley (1825–95)
“Dear to us are those who love us ... but dearer are those who reject us as unworthy, for they add another life; they build a heaven before us whereof we had not dreamed, and thereby supply to us new powers out of the recesses of the spirit, and urge us to new and unattempted performances.”
—Ralph Waldo Emerson (1803–1882)
“Culture means control over nature.”
—Johan Huizinga (1872–1945)