Pump protection system
First Claim
1. A protection system for a liquid pump, comprising a protection switch connected to a sensor for sensing a flow characteristic of liquid flow through the pump and for producing a signal indicative of the existence of that characteristic, means for rendering the pump operative or inoperative in dependence upon the presence or absence of a signal from the sensor, a manual override means for rendering the pump operative in the absence of a signal from the sensor and an override switch to switch off said pump, said override switch being connected to two signal-responsive switches, one for overriding the protection system and the other a latching switch establishing a control line in series with said protection switch.
7 Assignments
0 Petitions
Accused Products
Abstract
To protect the pump of a whirlpool bath against running dry and against blockage at the inlet, a pressure (or flow) sensor 14 senses pump pressure and generates a signal to keep a switch S2 in the pump motor electrical supply circuit closed. If the pressure signal ceases owing to blockage or running dry, the switch S2 opens. A manual override button 15 is held ON to close switches S1a and S1b in the power circuit for start-up. The sensor 14 and manual button 15 are preferably air pressure devices. Switch S1a is preferably an air-signal-operated latching switch whereby with the pump operating, the button 15 can be operated to switch the pump off. Relays RLA 1 and 2 may be used in conjunction with the electrical switches. A bleed hole may be provided between the button 15 and switch S1b to limit the period of time for which the motor could be run, with the bath empty, by prolonged inadvertent actuation of the button 15.
-
Citations
15 Claims
- 1. A protection system for a liquid pump, comprising a protection switch connected to a sensor for sensing a flow characteristic of liquid flow through the pump and for producing a signal indicative of the existence of that characteristic, means for rendering the pump operative or inoperative in dependence upon the presence or absence of a signal from the sensor, a manual override means for rendering the pump operative in the absence of a signal from the sensor and an override switch to switch off said pump, said override switch being connected to two signal-responsive switches, one for overriding the protection system and the other a latching switch establishing a control line in series with said protection switch.
Specification