VARIABLE SPEED WATER SUPPLY DEVICE

摘要

PURPOSE:To enable automatic start upon affirmative answer by comparing the operating condition under stoppage of pump due to inverter trip with predetermined conditions for safety operation. CONSTITUTION:Conditions for safety operation such as operating current, operating frequency, supply water pressure, etc. of motor 5 as pump system 6 to be determined from the rating of said pump system 6 are previously stored in a memory of computer of controller 4. The controller 4 will operate the end pressure of supply water on the basis of pressure signal SW from a pressure sensor 11 and frequency command signal Sf while also provided with the input current I of the motor 5 indicated on an ammeter 13. In the controller 4, CPU will compare the operating conditions under tripping with the conditions for safety operation to decide the cause of inverter 3 trip thus to decide the ability of starting operation automatically and to enable starting automatically if the answer is affirmative resulting in prevension of interruption of water supply due to unknown cause.