of circuits, helps to reduce the current-and what is more important-decreases the voltage that tries to re-establish itself at the moment the switch contacts separate. There is naturally a great difference in the switching task in the case of a breaker that controls a radial feeder compared with that of a parallel feeder, and, on the latter again, the switch that opens first on one end will probably not be taxed as heavily, despite the greater current, as the switch that opens last on the other end. Although there were isolated cases of switch failures on the combined system in recent years, accompanied by more or less severe oil fires and other secondary station trouble, an explanation for the comparatively small number of failures may be found (confirmed somewhat by the moving picture records taken during the tests) in a peculiar action of certain types of switches, that after a very small initial opening, close in again due to the upward pressure effect developed in the tanks. They remain closed in or possibly repeat this short opening and closing performance until the switches on the numerous tie-lines connecting the hydro generators to the distribution system had opened, and the steam turbines are demagnetized by the heavy short and inter-change current to a point where the combined. voltage and current rupturing task is small enough to permit dropping out of the switch without producing enough upward pressure to hold up the contacts. It should be understood that the relays themselves probably acted with a fair degree of selectiveness, i.e., in the case of either radial feeder or tie-line, the relays had released the trip mechanism with a sufficient time differential. As the short hung on, the sustained current brought other relays into play, which eventually tripped a number of tie-lines, the opening of which caused unnecessary loss of power. In other words, in practically every case of severe cable trouble on tie-lines the fault could be cleared only after the entire system voltage was pulled down and after the hydro and steam systems had separated, due to the falling out of step of the steam units. Subsequent to separation, each generating system must rebuild its own voltage and pull what synchronous apparatus it could back into step. As a rule the loss of voltage on the steam half of the system was about fifteen seconds, while on the hydro part of the system where the individual generators remained in synchronism voltage was restored in a shorter time, i.e., as soon as the tie-lines between the two systems had opened. Speaking in general for systems that are fed from more than one generating station, it is difficult to say whether this disarrangement of service, due to the separation of the system, is a lesser evil than the possibly increased number of oil switch failures at generating and substations with the accompanying station menace. It will be found inconvenient in many cases to balance the feeder connections in such a way that in the event of separation each onehalf will have sufficient capacity to carry the connected load, and that at the same time only such switches will act as tie breakers that are capable of interrupting the current; the cutting apart at times. causes overloading of the two separated systems, dropping of frequency and necessity of cutting off of some of the restored load before resynchronizing. A number of large distribution systems experienced severe tie-ups in recent years, as a result of insufficient synchronizing power between individual generators and between parallel stations accompanied by failure of oil switches to open the faulty circuits selectively, without holding down the voltage a longer time than is necessary for the operation of the switches. On some systems it was found advisable, since the inadequacy of switches was realized, to lengthen the time setting or to raise the current and time limit on the relays and to install reactances. Reactors properly distributed are a great help in maintaining synchronizing power between individual units and parallel stations, but they are not practical in many cases for reducing the short circuit current on individual feeders to a safe value that can be handled by some of the older type of switches. If the switch, itself, due to its peculiarities in the opening process, refuses to come out in the time given to it by the energizing relay, the entire system is made to suffer a prolonged loss of voltage, accompanied by heavy short circuits and exchange current conditions, which will not only disturb customers' service for an unduly long time, but will also tax to the limit the various station and feeder equipment that is not designed to stand heavy currents more than momentarily. In view of the large number of older type switches that are in use on the large distribution systems, the financial task of replacing them by new ones of adequate capacity is by no means a small one. Nevertheless, I believe that sooner or later all large distribution companies will be faced with the task of revamping most of their switching equipment and bus structure and even whole station layouts at generating as well as substations, in order to insure prompt and safe clearing of distribution trouble. It seems of great and immediate importance that manufacturers and operating companies co-operate in establishing a reliable one shot rating on the old type of switches. If no practical means are available to reduce the rupturing task in actual operation. to those limits, by separation of system, current limiting reactances, lengthening of relay settings, introduction of group switches, etc., some way should be found to modify the design of switch pots, contacts and other parts that are chiefly responsible for the limitation of rupturing capacity, and to again establish the limits with those modifications. It may even be necessary to replace the entire switch mechanism and to use only the existing cell structures. This would require a less radical reconstruction of the whole station than if an entire new style of switch must be introduced. THE CHAIRMAN: We now come to the report of the Safety Rules Committee, Mr. Thomas I had occasion to learn the earnest manner, the deep Sproule, Chairman. THOMAS SPROULE: Mr. Chairman and Gentlemen-It was expected that the report of the Safety Rules Committee, which deals principally with the National Electrical Safety Code, would have been discussed by Dr. Rosa, who has been so actively associated with that work and with whom your Committee has been constantly in touch. Owing to the death of Dr. Rosa on May 17th, it seems to your Committee inadvisable to discuss its report at this meeting. Therefore, the report is presented by title only. It might interest the meeting to know that within two weeks of the Doctor's death, Mr. Moultrop, Mr. Carle, Mr. Canada and the speaker, visited the Bureau in an endeavor to get reconsideration given to the loading rules in Part 2 of the Code. We were most courteously received and a new plan of procedure was outlined. This was followed shortly thereafter by a meeting in New York, presided over by Dr. Rosa, at which the details of this plan were arranged for. We feel that this is very tangible evidence of the hearty co-operation shown by the Doctor, and his death, which occurred within such a short time, prompts your Committee to forego the presentation of its report except by title and to request your approval of the following resolution. (Reading resolution.) MR. SCHUCHARDT: It is with a sense of deep appreciation of the loss to this Association in the death of Dr. Rosa that I second the adoption of that resolution unanimously. W. J. CANADA: I take the very greatest pleasure in seconding the adoption of this resolution. As most of you know, for a number of years I was closely associated with Dr. Rosa in this piece of work which is the subject of this report-safety rules of the Bureau of Standards. In that period. thought, the constant search after real truth which Dr. Rosa applied to this work. I believe that in increasing degree this has been recognized by the electrical industry, and by our own branch particularly, during the past two or three years. This latest development of this co-operative work, through the Safety Rules Committee, which was just brought to an end two weeks after its inception by the untimely death of Dr. Rosa, leaves us with a feeling of loss and a great feeling that you must in some way find a means for carrying on the work and carrying on that thorough co-operation with our Governmental bodies which was so happily under way at the time of Dr Rosa's death. W. C. L. EGLIN: I would like to endorse the action taken by the present Committee. Through our contact I came to have a high regard for Dr. Rosa; for his integrity as a man, for his high sense of honor, and more especially for his keen sense of duty. There was no time in any of our connections with Dr. Rosa when all of these characteristics were not always in evidence; and that is one of the things we all like to look back upon; also, that he was a real man; that he was honest and was true, and that he was always working and striving for what was best. THE CHAIRMAN: Gentlemen, you have heard the resolution. It is now up for your action. (The resolution was thereupon unanimously adopted.) MR. SPROULE: I might add, if anyone has come here to discuss the Code, I would be glad to have it sent to me. THE CHAIRMAN: This meeting will now stand adjourned until 2:15 tomorrow, Thursday after noon. (Adjourned) First Technical National Section Parallel Session Tuesday, May 31, 1921, 4:00 P. M. The meeting was called to order by the ViceChairman, Mr. N. A. Carle. CHAIRMAN CARLE: I don't want you to think you have got a new meter Chairman. I am simply opening the meeting as the Vice-Chairman of the Technical Section, which is a prerogative we have of appearing before the Chairman himself appears, and immediately thereafter the meeting is given to the Chairman and he conducts the matter of discussion. I think you are to be very much congratulated on the work you have done. I congratulate you on your Chairman, Mr. Wadsworth, who is serving his first year and I think I am correct in saying it is not going to be his last. He and the Committee have done a very fine piece of work. I am going to steal this much from him. I am going to read the abstract: "The Meter Committee has this year carried out the suggestions contained in last year's report, the most important of which was the subject of kv-a. measurement. The report contains descriptive matter and diagrams of the various methods used by member companies. The meter lecture, which has been in course of preparation for some time, finally has been completed, and is printed in full as Appendix I to the report. Other subjects included are shown in the table of contents." Mr. Wadsworth, will you present your report? W. L. WADSWORTH: As usual, the hardest fellows we meter men have to convince are our own company employes. Of course the meters are always correct. We do not give in to the employes at all. Now, knowing that you have all studied this meter report last night before you went to bed, and have come prepared to give it very frank discussion, which we want, we don't care what you say-pull it to pieces, tell us what is bad about it. I do not believe it is necessary for me to say very much about the report. It is your Committee and what we are trying to find out is what you men want. We will investigate and report anything that you ask us to do. Report of Meter This year the Committee has had the opportunity of working with a large membership, augmented by appointments from several of the Geographic Divisions. It should follow that from this widespread geographical representation more material would be brought before the Committee for consideration and possibly more effective work accomplished. Very little can be said concerning this new feature of the committee organization, aside from the fact that it will be necessary to formulate some detailed method of procedure between the National Committee and the Geographical Committee to foster cooperative action and thereby prevent possible waste or unnecessary duplication of effort. One of the Meter Committee meetings this year was held at Salt Lake City, Utah. It was expected at this meeting to have a representative body of eastern and western members, and that by having a general discussion and an exchange of views regarding the common problems confronting us, much good would result. It is regrettable that the attendance at this meeting was most unsatisfactory. The Committee, however, must report that considerable work has been accomplished by the Pacific Coast Division, and the reports that have been received regarding the several matters under consideration by your Committee this year have been carefully studied and have been combined with reports from other sources and included in this report. The possible revision of the Meter Code is a matter which has been brought to the Committee's attention. It is proposed to reprint the code, revised, if Committee necessary, in 1922. This revision can only be made jointly with the Association of Edison Illuminating Companies' Committee on Metering and Service Methods and the Electrical Testing Laboratories. Preliminary steps have been taken by both committees to ascertain the necessity of revision. Your Committee requests that the chairman be advised immediately of any suggestions you may have relative to the code. Your prompt and careful consideration of this matter will expedite the work of those responsible for the satisfactory completion of this important task. Following the excellent suggestion in last year's report regarding a general meeting of men interested in electrical measurements and meter maintenance, a meeting of this character was arranged with the Empire State Gas and Electric Association and held at Buffalo on December 9, 1920. Two speakers were obtained-one who discussed the measurement of maximum demand, and the other who outlined the essentials of electric measuring instrument design. It can be stated that the meeting was a success, and it is hoped that other meetings of this character will be arranged. One important part of the Committee's work. which does not appear in the body of the report is a compilation and digest of all the recommendations of the Meter Committee of this Association and also of the Committee on Metering and Service Methods of the Association of Edison Illuminating Companies made during past years. It is proposed to study these recommendations, amend them as the change in the art demands, and take any other action that may be deemed advisable. This year the Committee has appointed a Subcommittee on Standardization of Meter and Instrument Design. It is the intention that this subcommittee, cooperating with the manufacturers, will consider any proposed changes in meters or instruments and also will make preliminary investigations of new devices for the benefit of the Committee. It is the belief that the Subcommittee can present information regarding new apparatus to the Committee in such a manner that the manufacturers and the Committee will derive valuable information quicker than waiting for initial introduction. of the apparatus to the whole Committee. Printed as Appendix I to this report is the Meter Lecture which was briefly described in the report of 1920. Copies of the Meter Lecture, together with lantern slides corresponding to the figures and illustrations thereof, are maintained at N.E.L.A. headquarters and are at all times available for the use of meter departments throughout the country. Education of Metermen The Committee felt that it would be advisable, if possible, to prepare a detailed standard course for training metermen, or at least to keep in close touch with and guide those universities, manufacturers or utilities giving meter courses. While it has been found impracticable to finish the detailed course this year, considerable information has been gathered that will serve as a foundation for this course. It is still the opinion of the Committee that a detailed standard course is required, and it is hoped that the work will be continued and completed. University Courses The following is a brief outline of educational courses for metermen as obtained from the various universities. Two manufacturers' courses are also included for comparison. These outlines were obtained from replies to inquiries sent to the University of Illinois, Iowa State College, University of Arkansas, University of Wisconsin, Westinghouse Electric & Manufacturing Company and the General Electric Company. In each case an inquiry was made whether they knew of any other universities, colleges or manufacturing companies conducting such courses and, as they all referred to one or more of those to whom inquiries had been sent, it is probable that these are the only courses conducted at this time, or contemplated. The periods of these courses as given by the universities ranged from four days to two weeks, while those given by the manufacturers ranged from four. years to eighteen months. The hours of instruction were from eight A.M. to ten P.M., and consisted of lectures, talks by various manufacturers' representatives, and laboratory work on principles of meter practice as discussed previously in the lectures. An outline of subjects covered by the universities in these special courses is as follows: University of Illinois Period of course-June 21st to July 3, 1920. First week, instruction for beginners-34 present. terminations; alternators; Ohms law for A.C. cirUnits; Ohms Law, for D.C. circuits; resistance decuits; principles and study of indicating instruments; clock and disc constants and gear ratio of watthour meter; meter characteristic curves, theory and calibration of D.C. watthour meters; principles and calibration of A.C. watthour meters; calibration of rotating standards. Examination on foregoing subjects. Second week, instruction for more advanced students 44 present. Polyphase alternators and circuits; 3-phase current and voltage relations; general characteristics and tests of transformers; general study of polyphase meters; construction, connections and calibration of polyphase meters; polyphase meters with transformers; calibration of polyphase meters with transformers; graphic recording meters; demand meters and power factor meters; study of graphic meters; special experiments and calibration of standards. Examination on foregoing. Iowa State College January 4th to 7, 1921. Attendance-71 men. The fundamental principles upon which meters operate; the function of mechanical and electrical features used in the construction of meters; installation, wiring, testing and adjusting of meters for single-phase and polyphase service; adjustments for light and full load; general assembly and repair in connection with maintenance; special problems brought in by metermen. University of Arkansas October 11th to 15, 1920. Attendance-44 men. The D.C. circuit; the A.C. circuit; calibration and adjustment of the D.C. watthour meter; the singlephase A.C. meter, calibration and adjustment of same; metermen's problems. University of Wisconsin January 31st to February 4, 1921. (a) Indicating Instrument: 1.-Examination of different types of indicating instruments. 2.-Comparison of readings of different types of indicating instruments when used on: (a) Continuous current, (b) alternating current, (c) pulsating direct current. 3.-Calibration of an amme ter. 4.-Calibration of a voltmeter. 5.-Calibration boards and switchboard details; transformers, with of a wattmeter. (b) Watthour Meters 6.-Examinations of a commutator type meter. 7.— Examination of mercury type meter. 8.-Examination of induction type meter. 9. Installation of three-wire meter. 10.-Installation of polyphase meter without transformers. 11.-Installation of polyphase meter with instrument transformers. 12. -Calibration of direct current meter with rotating standard. 13.-Calibration of single-phase meter with rotating standard. 14.-Calibration of threewire meter with rotating standard. 15.-Calibration of polyphase meter with rotating standard. 16.— Calibration of direct current meter with ammeter and voltmeter. 17.-Calibration of rotating standard 22. Methods of obtaining low power factor loads. 23. Installation of two or more service meters as "shop standards." The manufacturers' courses are more comprehen sive and are intended to train men for meter testers and, possibly, to hold responsible positions in the meter departments. An outline of courses as given by two manufacturing companies is as follows: General Electric Company, West Lynn, Mass. Three months' factory experience in the meter assembly department; nine months in the meter testing department; three months in the instrument assembly department. The experience in testing shop plant meters is also included. The above is supplemented by a three-months' course of instruction in fundamentals of electricity at the apprentice school, and lectures by engineers of the department. All appliAll applicants for the course are required to be high school graduates. particular reference to instrument transformers of all types; power house work where the students pay particular attention to the use and mounting of instruments on switchboard; general factory wiring and testing. After the above work has been completed the students are assigned to the standardizing laboratory for a period of six months, after which they are sent to the Newark Works, where the meters and instruments are manufactured, where a thorough course in the manufacture and commercial testing of meters is given. Three-year course. Applicants must have had four years of high school work. The course as given is the same as above, but is supplemented by an engineering course at a night school in order that the applicant will be better able to study the underlying theory. Discussion of University Courses Several members of the National Meter Committee, including the chairman, attended the university courses with the intention of offering every possible assistance and cooperation, and the conviction of all was that the universities are supplying very ably a most urgent need. At Ames, Iowa, as well as at Urbana, Illinois, where courses previously given were repeated during the past year, both instructors and students were impressed even more strongly than before of the valuable and lasting results obtained. The metermen who attended the courses as students showed by their interest and strict attention to the work that they appreciated the opportunity to make themselves more valuable to their companies. The National Meter Committee has gone on record as offering every assistance possible to such educational institutions as may conduct courses for metermen, and it is hoped that many other schools and colleges will see fit to open similar curricula for the benefit of both individuals and operating companies. The Meter Lecture as prepared by this year's Committee has been found to supply a very much. needed educational opportunity. It therefore has been decided to print it complete in conjunction with this report, in order that the information collected may be more generally available. Revision of Bureau of Standards Circular No. 56 The Bureau of Standards reports some progress in the revision of Circular No. 56, "Standards for Electric Service," and anticipates increasing its activities thereon within a few months. This circular is comprehensive in character and is Westinghouse Electric and Manufacturing Company, intended primarily as an aid to public service com East Pittsburgh, Pa. Four-year course for meter specialists. Applicants for this course must have two years of high school work. The work as outlined includes A.C. and D.C. motor winding and connecting; work on switch missions in formulating rules governing the methods used by public utilities in furnishing service, and cannot but deeply interest member companies of the Association. Copies may be obtained by application to Dr. S. W. Stratton, Director, Bureau of Standards, Department of Commerce, Washington, D. C. |