WATER SUPPLY UNIT

Japanese Patent JP2017048794

A

PROBLEM TO BE SOLVED: To avoid suspension of water supply as much as possible when an abnormal value is detected during operation, by not stopping as a failure but preferentially continuing the operation with lowered performance.SOLUTION: A water supply unit comprises: an electric motor 20 for variable speed driving of a vortex pump 12 by an inverter; an electric part 50 to drive an electric motor 20; a converter part 61 to convert the AC from a commercial power source to the DC; a storage part 80 to store a maximum rotation speed of the electric motor 20, a reduction warning voltage of a DC voltage of the converter part 61, a voltage monitoring time, an acceleration time of the electric motor 20, and a target discharge pressure of the vortex pump 12; and a control part 70. When the DC voltage of the converter part 61 has reduced to the reduction warning voltage or less, the control part controls to: if the electric motor 20 is being accelerated, stop acceleration and set a new acceleration time longer than the present acceleration time in the storage part 80; if it is in constant speed operation and has not reached the maximum rotation speed, reduce the target discharge pressure by a prescribed value and set it in the storage part 80; and, if it is in the constant speed operation and has already reached the maximum rotation speed, reduce the maximum rotation speed by a prescribed value and set it in the storage part 80.SELECTED DRAWING: Figure 1

JPS6012853	[Title of the Invention] Electric motor overcurrent protection device
JPH078854	[Name of device] Compressor

SAKATANI TETSUNORI
YAMAZAKI SHUHEI
ITO TOMOHIRO
WATANABE SHOTA

JP2016217478A

March 09, 2017

November 07, 2016

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KAWAMOTO PUMP MFG

F04B49/10; F04B49/06; F04D15/00

Kurata Masatoshi
Nobuhisa Nogawa
Naoki Kono

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