| 摘要 |
PURPOSE:To invariably secure stable operatings by performing automatic corrections of phase connections, intermittent and automatic control operations in relation with aerial/air-water operations, automatic stops at overcurrent and open phase, and automatic stops in case of accidents such as impeller lock, etc. CONSTITUTION:A phase rotation judging relay 5 is switched by a phase rotation judging circuit 4 so that the phase rotation of a submersible pump 2 side is invariably connected normally. At open phase and overcurren, a main relay 18 is forcibly opened and is not resumed unless a main unit power supply 19 consisting of a circuit power supply 19b and a relay power supply 19a is turned off. When the submersible pump 2 is installed under the water for operation and the water level is lowered to start aerial operations, air-water operation judging circuit 12 is activaged to open the main relay 18, and the submersible pump 2 performs intermittent operations including 1-15min stops preset by a variable resistor 13 for setting a rest time and switching continuous/intermittent operations in consistency with respective usage conditions. According to the said constitution, the submersible pump 2 can be invariably operated under stable conditions. |
