Electricity: motive power systems – Induction motor systems – Primary circuit control
Patent
1989-05-05
1991-03-26
Smith, Jr., David
Electricity: motive power systems
Induction motor systems
Primary circuit control
318809, H02P 540, H02P 128
Patent
active
050032429
ABSTRACT:
A reduced voltage starter for gradually starting a polyphase motor having an acceleration control circuit for gradually applying power to the motor and detector circuits for detecting various fault conditions for terminating power to the motor. A shorted solid state switch detector senses when one of the semiconductor switches applying power to the motor is shorted to terminate the application of power from the remaining phases. A phase angle control circuit insures a uniform application of power to the motor. A phase rotation detection circuit detects when the three phases are in other than their correct sequence and terminates power in the event of such detection. An underload detection circuit senses when the current drops beneath a preselected reference after the motor has reached its full speed and terminates power in response to such detection. A line-to-line to line-to-neutral convertor produces signals representative of the line-to-neutral voltages which are necessary for other circuit functions.
REFERENCES:
patent: 3670237 (1972-06-01), Hubel et al.
patent: 4072880 (1978-02-01), Oshima et al.
patent: 4084406 (1978-04-01), Brenneman
patent: 4355274 (1982-10-01), Bourbeau
patent: 4361793 (1982-11-01), Nordell
patent: 4384243 (1983-05-01), Maskovac
patent: 4468603 (1984-08-01), Vander Meer
Esce et al, "Soft-Start Conveyer Drives", E&MJ, Feb. 1980, pp. 84-89.
Gilroy Hugh M.
Smith Jr. David
Square D Company
LandOfFree
Reduced voltage starter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reduced voltage starter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reduced voltage starter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-619606