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Responding to Michael Griffin's Oct 17, 11:65 am reply... I too, did not think that the JIS Standards contain control symbology sought by james fang! I referenced the List Archives because at least two paths regarding availability were discussed. Regards, Phil Corso, PE {Boca Raton, FL...

Responding to james fang's Oct 14, 2:10am query... there are three "JIC" standards you seek! There is a lot of information covering these 1957 standards in the List's Archives. Search the "JIC" or start with: http://www.control.com/1026164855//index_html Regards, Phil Corso, PE {Boca...

Responding to ucf's Thu, Oct 13, 1:01am query: Typically, Vector-Group specification of power transformers is not used by USA manufacturers. Nevertheless, because English and German trafo manufacturers do, I suggest you contact those manufacturers or their world-wide affiliates. Failing...

Responding to Mark Heath's Fri, Sep 30, 1:33pm reply... dividing the single-phase load by root 3 is incorrect: If the 45A (3-ph) and 8.5A (1-ph) loads connected to ph-A have the same power factor, then, the total ph-A current is the arithmetic sum of their magnitudes. If the 3-ph and 1-ph...

Responding to James Smith's Sep 28, 10:17pm comment... in this instance bigger is not better: LAL pointed out that the major criterion is low cable-capacitance. As cable (wire) size increases so does its capacitance. Regards, Phil Corso, PE {Boca Raton, FL, USA} [[email protected]]...

Responding to Mike Bailey's Fri, Sep 23, 10:51pm comment... current flow between primary and secondary ground connectons is not the case: When an ungrounded primary of a transformer is supplied from a grounded source, and a ground-fault exists on the transformer secondary, then, there is no...

Responding to Anonymous' Mon, Sep 19, 11:55pm query... Presuming that there are no faults, then the ACB's instantaneous setting is "one of the usual suspects!" Regards, Phil Corso, PE {Boca Raton, FL, USA} [[email protected]] ([email protected])

Responding to Nallan's Sep 3, 12:19pm comments... there is some confusion on my part. Please confirm, refute, or clarify my understanding of your system configuration: 1) An isolation transformer is installed on each drive? It's primary/secondary winding configuration is delta/delta? 2) Is...

Respondng to Mark's Aug 30, 2:21pm comments... an astute observation. You are on the road toward the Blue Ribbon (1st prize!) (Who said ITs don't know no math!) Regards, Phil Corso, PE {Boca Raton, FL, USA} [[email protected]] ([email protected])

You can use your own ABC (Analysis Basis Criteria) making the soution as simple or complicated as you want! For example, I set Cv, Cd, and Cc to uinity. Regards, Phil Corso, PE {Boca Raton, FL, USA} [[email protected]] ([email protected])

Responding to Dave in Australia... tsk, tsk: An easy way to remember the Watt per Hp constant, 746, is that is half of 1492, the year of Columbus' great discovery. Well I think of it as a geat discovery! Of course many wish he had gone east instead of west! This comment reminds me of...

Replying to those who submitted answers: The Good News: All of you who gave the answer '10 hours' have won the Yellow Ribbon or 3rd prize. There were two stand-outs; a) Those with the answer '10' used the RxT approach. It is certainly an acceptable solution since the original question was...

Responding to mim's Aug 23, 6:00pm query... your proposal intrigues me: By definition the Yy0 connection, European practice, has 0°-phase shift between the primary and secondary winding. (In the USA, it is possible to have a 180° phase shift.) Hopefully, you are aware that use of the Y-Y...

1) Cable voltage-drop is 5.8%. 2) Bus voltage-drop can't be determined unless supply parameters are provided. 3) Formula @ http://control.com/1026178348/index_html. 4) For ABM conditions contact me. Regards, Phil Corso, PE {Boca Raton, FL, USA} [[email protected]] ([email protected])

Further to my earlier reply to Sandy's query about chance (probability).... following are reliability figures taken from IEEE Std 500-1984: "IEEE Guide To The Collection of Electrical, Electronic, Sensors, and Mechanical Equipment Reliability Data For Nuclear-Power Generating Stations"...

Responding to Sandy's Aug 19 query... probability is low: Since you can't open the unit for inspection, and there is no noticeable odor of burnt insulation, try x-ray! Some additional food for thought: 1) Is this a new or existing installation? If the latter how many inrush cycles has...

Responding to Phillip Kambonde's Aug 16, 1:26pm query: The formula for both single and three phase capacitors is given in thread: http://www.control.com/1026188311/index_html Now I have a a couple of questions for the data you provided: 1) How did you derive the Qc value shown (600)...

Responding to Anonymous' Aug 10, 11:48pm reply... are any of the following assumptions correct?: 1) The transformer LT is on the star-side, and the HT on the delta-side? 2) The star mid-point is earthed? 3) Distance/grid protection (essentially measuring line impedance to the fault...

Replying to Andy's Tue, Aug 9, 3:12pm reply: If the sending-end and receiving-end voltage triangles are similar and the load is balanced, meaning little neutral current, then, what you propose is acceptable. Conversely, if there is considerable difference in the two triangles or there is a...