That crossed my mind but the motors are three phase 400 cycle. 400 cycle is a 2.5 ms period, then you have the three phase and number of poles so the period associated with anything rotationally related to the motor would be much less than a millisecond, or that was my thought process at any rate.
---------- >From: "Price, Ed" <ed.pr...@cubic.com> >To: "'Ken Javor'" <ken.ja...@emccompliance.com>, emc-p...@majordomo.ieee.org >Subject: RE: broadband RE from AC induction motors >Date: Mon, Jan 28, 2002, 8:45 AM > >>-----Original Message----- >>From: Ken Javor [mailto:ken.ja...@emccompliance.com] >>Sent: Friday, January 25, 2002 10:09 AM >>To: emc-p...@majordomo.ieee.org >>Subject: broadband RE from AC induction motors >> >> >> >>Do any forum members have knowledge of a mechanism by which ac >>induction >>motors (two are fan motors, one a compressor motor) can >>generate broadband >>RE from 30 - 600 MHz? This is outside my experience. Are >>there perhaps >>degradation modes that result in arcing? The motors run off >>three phase 400 >>cycle power, 115 Volts rms phase to neutral. The control system is >>bang-bang, just mechanical relays making >>connections/disconnections based on >>temperature and pressure inputs. The rep rate of the BB noise >>is variable >>but around 10 milliseconds. >> >>Thank you. > > > Possibly ESD caused by motion of the air over the rotor, with a regular > discharge from a pole-piece? Can you relate the 10 ms interval to the RPM > and number of pole-pieces? > > Ed > > > Ed Price > ed.pr...@cubic.com > Electromagnetic Compatibility Lab > Cubic Defense Systems > San Diego, CA USA > 858-505-2780 (Voice) > 858-505-1583 (Fax) > Military & Avionics EMC Services Is Our Specialty > Shake-Bake-Shock - Metrology - Reliability Analysis > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
