Positive temperature coefficient (PTC) electric immersion heaters
With PTC technology, thermal over-temperature protectors are no longer required to ensure safe operation. PTC aquaculture heaters are more dependable with extended service life and will not burn out in air like traditional resistance heaters. Unlike resistance heaters, these heaters continue working in high solids applications.
A PTC heater utilizes solid-state ceramic heating elements as its heat source. These devices are "self-regulating"—the maximum temperature is internally limited regardless of the operating conditions. Therefore, these heaters have a built-in safety never seen before in electric immersion heaters. Traditional resistance heaters have the potential for a runaway heat condition if operated out of water, but a PTC heater can self limit its maximum temperature regardless if operated in water, air or completely surrounded by solids.
If the temperature goes down, so does the resistance (thereby increasing power output). If the heat transfer is impeded, as would happen when operating in air, the temperature will increase (as will the resistance), resulting in reduced power output. This concept is similar to technologies used in car seat warmers or hair dryers—a unit can only reach a predetermined maximum temperature before it turns itself down.
In the aquaculture industry, a common threat to heater life is buildup in waters with dense solids resulting in overheat conditions. Since these conditions will not cause the SmartOne® to overheat, it will last significantly longer than a traditional heater. The maximum output temperature is below the ignition point of most plastic tanks as well, so overheat damage is prevented if the element is operated in air or becomes covered with buildup. (Please note: periodic cleaning is still recommended since buildup can increase the rate of chemical corrosion of any heater.)
SmartOne® is a registered trademark of Tom Richard, Inc. DBA Process Technology.