| 摘要 |
PURPOSE:To surely detect the consumption of a corrosion preventive bar and to permit the prevention of no-water burning by comparing the potential difference generated between the corrosion preventive bar inserted into a vessel body and vessel body wall with a reference potential difference preliminarily stored in a control part and discriminating the same. CONSTITUTION:The water in the vessel body 1 provided with a water feed pipe 2 and a hot water feed pipe 3 is heated by a heater 4 and the temp. thereof is detected by a temp. sensor 5. The heater 4 is regulated by a control part 6 to control said temp. The corrosion preventive bar 7 as a sacrificial anode inserted into an aperture 9 bored to the vessel body wall 8 of the above-mentioned storage type electric water heater is airtightly mounted via an insulating gasket 11. The corrosion preventive bar 7 and the vessel body wall 8 are wired in a wiring part 14 by interposing a relay contact 12 therebetween. The corrosion prevention of the vessel body 1 is executed by closing the contact 12 and the contact is opened periodically or according to the liquid temp. in the vessel body 1 to take in the potential difference between the bar 7 and the wall 8 from a branch point 15 of the wiring part 14. The potential difference is compared with the reference potential difference stored in the control part 6 and is discriminated. The result of the comparison is announced to the operator by a display part 16. |
