Safety system and method for pump and motor

• US 8,564,233 B2
• Filed: 06/09/2009
• Issued: 10/22/2013
• Est. Priority Date: 06/09/2009
• Status: Expired due to Fees

• Current Assignee: Briggs & Stratton Corporation, Danfoss Low Power Drives, Pentair Flow Technologies LLC (Pentair Plc (Ireland))
• Original Assignee: Danfoss Low Power Drives, Sta-Rite Industries LLC (Pentair Plc (Ireland))
• Inventors: Kidd, Melissa Drechsel, Genaw, William James, Pasche, Micheal Robert, Baase, Gary Thomas II, Berthelsen, Lars Hoffmann, Fink, Rasmus, Holm, Martin Skov
• Primary Examiner(s): DUDA, RINA I
• Application Number:
  US12/481,455
• Publication Number:
  US 20100312398A1
• Time in Patent Office: 1,596 Days
• Field of Search: 318/432, 318/434, 318/629, 318/632, 318/671
• US Class Current: 318/432
• CPC Class Codes: F04D 15/0066 by changing the speed, e.g. of the driving engine
• CPC Class Codes: H02H 1/04 Arrangements for preventing response to transient abnormal conditions, e.g. to lightning or to short duration over voltage or oscillations; Damping the influence of dc component by short circuits in ac networks
• CPC Class Codes: H02H 7/0822 Integrated protection, motor control centres
• CPC Class Codes: H02P 25/04 Single phase motors, e.g. capacitor motors

Abstract

Embodiments of the invention provide a variable frequency drive system and a method of controlling a pump driven by a motor with the pump in fluid communication with a fluid system. The drive system and method can provide one or more of the following: a sleep mode, pipe break detection, a line fill mode, an automatic start mode, dry run protection, an electromagnetic interference filter compatible with a ground fault circuit interrupter, two-wire and three-wire and three-phase motor compatibility, a simple start-up process, automatic password protection, a pump out mode, digital input/output terminals, and removable input and output power terminal blocks.

Claims

1. A method of controlling a pump driven by a motor, the motor being connected to ground, and a variable frequency drive connected to the motor, the method comprising:

operating the variable frequency drive so the motor is being driven and the variable frequency drive is regulating a speed of the pump in a substantially continuous operation;

sensing a current between the variable frequency drive, the motor, and ground;

determining whether there has been a loss of current indicating a ground fault;

simultaneously operating the variable frequency drive, the motor, and an electromagnetic interference filter while sensing the current and determining whether there has been a loss of current; and

removing power from the variable frequency drive and the motor substantially immediately when there has been a loss of current.

2. The method of claim 1 and further comprising reducing electrical noise generated by the motor and simultaneously providing protection against shock.

3. The method of claim 1 and further comprising operating the electromagnetic interference filter in order to help prevent noise interference with AM radio.