SAFETY DEVICE OF UNDERWATER HEATER, AND UNDERWATER HEATER PROVIDED WITH SAFETY MECHANISM

摘要

PURPOSE: To materialize the safety device of an underwater heater, which can surely turn off an underwater heater and prevent the occurrence of fire effectively, in case of the flowing out of breeding water in a water tank due to the earthquake or the like. ;CONSTITUTION: This is a safety device 10 for an underwater heater equipped with a first plug 18 for power connection, a plug socket for supplying power to an underwater heater 50 connected to itself, and a first sensor 13 encasing a fuse resistor 22 within its casing 20, the fuse resistor is equipped with an insulating substrate, a heating resistor covering the surface of the insulating substrate and also being connected in series to the underwater heater 50 and generating heat by the application of a power current so as to heat the insulating substrate, and a waterproof film made of glass covering the surface of the heating resistor. The strength of the insulating substrate is set so that the insulating substrate is crushed, causing thermal distortion, and the heating resistor being a power supply path is cut off, in the case where water within the water tank 12 does not exist around the waterproof film, and also it may not be crushed in the case where water exists around it.;COPYRIGHT: (C)1996,JPO