The function of sheathed electric heater

Sheathed electric heaters are used to heat hydraulic and lubricating oils in hydraulic and lubrication systems. They can also be used to heat non-corrosive gases or liquids. They consist of a heater core and a sheath. The heater core uses a high-temperature-resistant alloy heating wire as the heat source and high-temperature-resistant ceramic as the insulation medium. The sheath is made of cold-drawn seamless steel pipe or stainless steel and is flange-connected to the tank. The sheath isolates the heater core from the heated fluid. When replacing a sheathed electric heater, there's no need to drain the oil in the tank; simply remove the heater core and replace it with a new one, making maintenance easy.

Sheathed electric heaters feature automatic insulation resistance range switching for easy reading. They also measure ambient temperature. The digital insulation resistance tester has an automatic timer function and emits a short beep every 15 seconds. It automatically measures, calculates, and stores absorption ratio and polarization index values. Its output short-circuit current is greater than 5 mA, meeting the requirements for fast charging of capacitive loads. It has strong anti-interference capabilities, stable and reliable readings, and comprehensive protection features ensure safe operation. Powered by a rechargeable lithium battery, it automatically shuts down when the battery is low. It can no longer meet the verification work of modern microcomputer relay protection. With the continuous development of science and technology, microcomputer relay protection test systems have been widely used in various fields such as line protection, main transformer differential protection, excitation control, etc., and substation integrated automation has become the mainstream.