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pp: I don't quite understand RC function. Are you using RC components across the breaker's contacts to aid or enhance its interrupting and/or first-cycle peak-withstand capability? If so, then breaker is inadequate for the duty being imposed!! Alternatively, if RC components are installed as...

Are you using the RC components to minimize arcing across an opening contact? If so, then you are referring to an "Absorption Circuit". Refer to any text on "Relay Engineering!" One cautionary note. A rigorous calculation will probably yield no more of a "proper" solution than will trial and...

Further to my Thu, Jun 6, 5:57 response, a rather simple arcing-fault detector is available in the form of an AM radio receiver. It can even pickup very low-magnitude slip-ring arcing, Regards, Phil Corso, PE (Boca Raton, FL)

Unfortunately my view of Project Approvals or Expenditures, based on ROI (Return On Investment) or technical (it's the latest) merit, is somewhat cynical. I worked for a number of medium, large, and extra-large companies. Authorization success was often achieved by: a) Cost estimates...

Paul... an example: The HPI (Hydrocarbon Processing Industry) have long standing Standards that cover virtually every instrument installation known... even some unknown! IMO, Area Classification layout should be 3rd, immediately after Process Facility layout and an Electric (the only true...

I disagree with Paul T's statement that "... the only difference is the enclosure that it comes in..."! Certification of Class I enclosures insures that effects of a possible explosion, resulting from the coincident occurrence of a flammable air/gas mixture, and a source of ignition in the...

Responding to Meonly's Thu, Jun 6, 4:35 pm query: The rotor windings of a slip-ring (or wound-rotor) motor consist of three independent coils, usually connected in a 3-phase star (wye), sometimes in delta (mesh)... as are the stator windings. Such motors are used in applictions requiring...

If you want definitions, look in previously mentioned: I.E.E.E Std 100-1992 "The New IEEE Standard Dictionary of Electrical and Electronics Terms" Regards, Phil Corso, PE (Boca Raton, FL)

Responding to "Who Cares" query, I do: If your question is a general one, look into NEMA Standards Covering Large AC Machines. Being more specific, critical speed for AC motors is not a usual concern unless it is very large, having 2-poles (more rarely 4), and if its rotor is of the...

Further to A. Kersten's comments: The Cookbook Anthony referred to may be: "CMOS Cookbook" by Don Lancaster published by Howard. W Sams & Co., Inc. ISBN 0-672-21398-2 An earlier reference was: "Solid-State pH Meter" Popular Electronics November Issue, 1968 Regards, Phil Corso...

Responding to [G]eronimo's Tue, May 28, 3:45 pm query: How about using the motor to lift a known weight, a specified height, in a measured length of time! Regards, Phil Corso, PE (Boca Raton, FL)

Check List Archive for threads on this subject. Regards, Phil Corso, PE (Boca Raton, FL)

Two methods are outlined in: "The Control of Boilers" by Sam G. Dukelow Copyright ISA, 1991 ISBN 1-55617-330-x Regards, Phil Corso, PE (Boca Raton, FL)

Responding to Bob Peterson's Fri, May 17, 10:56 am, comments regarding USA practice covering "neutral" nomenclature: By definition the "neutral conductor" is the one that usually is grounded and has equipotential (excluding phase displacement) measurements from every other conductor...

Further to Mark Hill's query: If you don't want to design your own Xmit & Rcvr circuits, then I suggest you contact "BitLink" of Denmark. They have a series of solid-state and semiconductor DIN-rail modules.... 8-bit is a standard unit. Regards, Phil Corso, PE (Boca Raton, FL)

Responding to Mark Hill's Thu, May 9, 11:33 am query: Sounds like a job for... no, not Superman, not even Spiderman, but... PAMman. Yes the old and forgotten Pulse Amplitude Modulation circuit. For some guidance, check Radio Shack's "Getting Started in Electronics"! Another reference is...

Responding to Bob Gantt's Mon, May 6, 5:01 pm, comments: Unfortunately your perception that a flame detector failure "ON" is unlikely is certainly not supported by statistics. I investigated several cases involving flame-detector failure. Although most were catastrophes involving only plant...

NFPA 85 is a compilation of NFPA 8501 thru 8506. Regards, Phil Corso, PE (Boca Raton, FL)

Responding to Jeff's Apr 16, 5:29 pm query: Way back when, we used such transformers on a machine that burned small holes thru the paper strip used to bond/cover joints in gypsum wallboard. They were connected to a rotating mechanical rectifier. Try Thomas Register! Also, I just came...

For a very good primer on the subject, get a copy of ISA's: Title: "The Control of Boilers" Auth: Sam G. Dukelow Publ: ISA (Research Triangle Park, NC) ISBN: 1-55617-330-x Regards, Phil Corso, PE (Boca Raton, FL)