During inspections in explosion-proof areas, if a burnt smell is detected or the heater junction box is found to have an elevated temperature, it usually indicates loose terminal connections or aged seals, requiring shutdown for handling. Compared with ordinary tubular electric heaters, the FBDR-12 stainless steel explosion-proof heater has an additional flameproof enclosure and an increased-safety terminal chamber. An insulation resistance below 1 MΩ indicates moisture ingress, and the heater should be dried before being put back into operation.
Ordinary heaters require additional isolation in explosive gas atmospheres, whereas this model's enclosure is designed according to flameproof standards and can be installed directly in Zone 1 and Zone 2. When replacing components on site, ordinary types can be withdrawn as a whole, while this model must first be de-energized, the flameproof end cover removed, and the flameproof surface checked for dents or damage. Damage to the flameproof surface reduces safety performance, and sanding with abrasive paper is not recommended.
The maximum operating temperature is 300°C. It is recommended to measure the temperature once a month, and the terminal chamber temperature should not exceed the ambient temperature by 20°C. When used for heating water, oil, or acid-base solutions, attention should be paid to surface overheating caused by scaling; in petroleum storage tank heat tracing and chemical reactor insulation scenarios, the medium liquid level must always submerge the heating section to avoid dry burning. Pharmaceutical purified water systems require regular testing of the enclosure grounding resistance, which should be less than 4Ω.
Before long-term shutdown, internal moisture must be blown dry and the cable entry sealed. Before restarting, measure the insulation resistance and grounding continuity, and confirm that the flameproof joint surface is free of rust and that all fastening bolts are complete. Maintenance records should include insulation values, temperature, and ambient humidity to facilitate trend judgment.
