[D8836ABG], Report from Edison United Manufacturing Co, Cornelius J Field to W W Carlin, December 4th, 1888


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[D8836ABG], Report from Edison United Manufacturing Co, Cornelius J Field to W W Carlin, December 4th, 1888

Editor's Notes

"We have the honor of submitting to you the following report of the test made of the electric light plant installed by the Edison United Manufacturing Company, of New York, at the new building of Messrs. Barnes, Hengerer & Co. at Buffalo, N.Y. ### The contract and specifications call for test to be made of plant on completion of work, before the acceptance of it, for determining the compliance with all points called for in the contract, in regard to capacity of plant, efficiency in operation, and other points in question. ### The plant in question was installed by the Edison United Manufacturing Company, and we consider it one of the best plants we have in operation, and to include many new points not heretofore combined in any isolated plant, and to fully comply with all points of the specifications in every respect. The operation of the plant, from a general inspection of it, shows that the work of installation has been carefully done in all respects, and the capacity of the machines and wiring, as shown by the test, is more than that called for. The distribution of lights is such as to give abundance of lighting in all parts of the building where it is required. ### There are two horizontal, automatic cut-off, 'Rice' engines, each with cylinder 11 inches in diameter by 20 inches stroke. ### There is also one horizontal, automatic cut-off, 'Rice' engine, with cylinder 5 inches in diameter by 10 inches stroke. ### Each of these two larger engines has a capacity of 80 horsepower, and the smaller one 10 horse-power, at 80 lbs. initial steam pressure, and cutting off at the quarter stroke. ### The engines are single-disc engines, with overhung pulley, and width of face required for driving two dynamos. ### There are four Edison Standard Compound Wound Dynamos, with a total rated capacity of 1600 lights, of 16-c.p. each, or their equivalent. ### There is also one Edison Standard Compound Wound Dynamo, with a capacity of 115 lights, of 15-c.p. each, or their equivalent. ### The 400 light machines have each a capacity of 200 amperes and 125 volts, the maximum e.m.f. being 125 volts. ### The 115 light machine has a capacity of 50 amperes and 125 volts. ### The voltage is adjusted at the point required by the drop on the line, in order to give the required e.m.f. of 110 volts. ### The 400 light machines run at their rated speed of 1200 revolutions per minute, and the 115 light machine at its rated speed of 1700 revolutions per minutes. ### These dynamos are automatic in their regulation, there being one hand regulator or resistance box connected in series with the shunt field of each dynamo, in order to adjust the dynamos at the proper e.m.f. for the lamps. ### The dynamos have also a shunt spool on the compound field of each machine, for adjusting the compounding as required by the dtrop on the line and the variation in the speed of the dynamo, in order to maintain constant e.m.f. under any changes of load without any hand adjustment. ### It has been shown that the cable connections between the positive brushes, bearing a given ratio in resistance to the cables between the brushes and swtich-board, will maintain even distribution of load over all the machines in circuit. ### There is one Standard Howell volt or pressure indicator, [zero reading instrument], connected across the line from the center of distribution, for indicating the pressure and enabling the attendant to see that the dynamos are maintaining uniform candle power under varying loads. ### There are individual ampere meters, one for each dynamo, to show constantly the amount of power being developed by the machine, and one main ampere meter, to show the total amount of power being developed by theplant. ### The wiring is done on separate feeders, and tied together in a closed crib, and also taking advantage of the system of double return circuits on the wiring. ### There are six vertical mains in the building, with feeder, one pole of which feeds in at the bottom and one at the top. ### All vertical mains are tied together at the center of distribution, about the third floor, by a closed crib system of connecting them together. This enables uniform pressure to be maintained throughout the system, under any conditions of change of load. ### The drop on the entire system was shown to be less than three volts, fully complying with the requirements of the specifications in this respect. ### All wire used on this plant is the best quality of Okonite insulation. ### All wiring in the building is moulded work, and is readily accessible. ### All cut-outs and switches used in the installation are made entirely of procelain or other non-combustible material, no wood being used in their construction. ### All lamps used in the installation are the new Edison standard lamps, 3.1 watts to the candle. ### Lamps called for in the contract are furnished and installed. ### Lamps were taken from the plant after being installed, and sent to Cornell University and tested. The lamps had been run some time, and under test as made there, with the instruments used by them, showed a mean horizontal candle-power at 110.28 volts, and in accordance with the test, this was the standard pressure used during the test of the plant. ### In accordance with the requirements of the contract and spcifications, test was made of this plant, extending over a period of several days, by The Edison United Manufacturing Company. The architecte was represented by Mr. Jesse M. Smith, electrical expert, of Detroit; The Edison United Manufacturing Company by Mr. C.J. Field, Chief Engineer, and Mr. Frank Bourne, Elecrtrician; and The Edison Machine Works by Mr. J. Dodd. All the points desired by Mr. Smith to be covered were covered, and his requests in regard to conducting the test were carried out, and we believe his report submitted to you will conform to the facts given here, and only show such differences in minor details as would occur in the preparation of two reports separately. We have tried to record here accurately, without going into too extensive details, the results of the test. ### The plant at the time fo the test had been operating for a period of nearly thirty days, without any interruption or accident of any kind, and giving every satisfaction, being run sometimes twenty-four hours without stopping. ### The distribution of the lights over the entire building is as follows: [chart that gives numbers by floor and street, chart that lists extra lamps by room] ### The test at Cornell University on lamps showed that each lamp at 110.28 volts would take .5078 ampere of current. ### The followign standard instruments for the test were used, the same being standardized at Cornell University: ### Volt Meters, on Howell No. 84, giving readings of 100z[?] volts; Howell No. 90, 100 z volts; Siemens, 111 volts; Cardew, 112.5 volts. ### The Howell was therefore assumed as the standard, and the Howell instruments were tested at Cornell University after the test, and showed results compared with the standard, the greatest variation being less than half a volt, and such variations were on parts of the scale that were not used at all over the entire range of the instrument, from 80 to 125 volts. ### Standard ampere meters were there, but were not used, as they were not required. ### Tabor standard steam engine indicators were used for indicating the engines. ## [chart of readings from Howell Standard Volt Meter] ### This shows a variation of one volt over the system; the specifications allow one volt above or below the normal, but this test shows one volt the extreme limit. ### [Measurements for engines A & B] ### The results of the cards taken on the test are given in the tables on the following page, which will be found to be self-explanatory. ### [tables for engines A & B] ### The table on the following page gives the output and efficiency of the dynamos, as shown by the indicator cards of engines, thus giving an average of 12.7 lamps to the horse power delivered at the pulley of the dynamo, for all cards. This makes no allowance for mechanical friction of dynamo bearings; this would be a small matter, though, and would not reduce this more than one or two tenths of one per cent. ### [table comparing engines A&B] ### The following data show the results of tests for dynamo efficiency: ### From Cornell University test of lamps, 16-c.p. ==110.28 volts, .5078 ampere. ### 800 16-c.p. lamps require 44,800 watts. ### 800 lamps == 407 amperes, == 60 Elec. H.P. ### Average indicated H.P. == mean between 61.31 and 63.28, == 62.4 Indicated H.P. ### Efficiency of dynamo == Elec.H.P./Ind. H.P. == 60/62.4 == 96% efficiency. ### The specifications also required the plant to be operated at full capacity for twenty-four hours. The plant was started up on Wednesday afternoon. The boilders were hardly ready and up to steam, so that the plant was really operated several hours before the regular test began, which was, as shown by the table, at 5.30, and continued until 5.30 the following afternoon. Ampere readings show the number of lamps in circuit, and the lamps were also counted, and known to be over 1600 in circuit. The boilers, though, were unable all the time to carry the required steam pressure, and also furnish the necessary steam required for operating the pumps and elevators in the building; and several times when the building was open, and when for other reasons the boilers were drawn on to a large extent, the pressure fell, and with it the amount of power furnished to the engines. This was, however, no fault of the electrical plant, and therefore the results should be considered satisfactory as far as showing that the dynamos were capable of operating the length of time called for in the specifications was concerned. The entire plant at the end of the run was in as good condition as when it started. The following are the facts in regard to this run of twenty-four hours: [table of results] ### The contract specifies that the dynamos shall be automatic in their regulation. Tests on this point were made several times, and the results obtained were entirely satisfactory. These tests were made, however, subsequent to the original test of the plant, at which time, for various reasons, satisfactory results on automatic regulation were not obtained. However, on our last trip to Buffalo, there meeting Mr. Smith, our Mr. Bourne adjusted the overcompounding of these machines, and we obtained remarkably good results. We give herewith a table showing the results with slight adjustment of the brushes, the rocker-arm being moved a total of about five-eighths of an inch. Mr. Smith also desired a test made without movement of the brushes; of course, to accomplish this, we had to alter the shunt spools to give more over-compounding. This was done, and the results obtained were even better than we had expected. As a result, Mr. Carlin and Mr. Smith, I may confidently say, have been converted to the Edison system, whereas before they wer ein favor of another system. ### The readigns for these tests were carefully taken, several instruments being used, and simultaneous readings being taken on all. The pressure was taken at the lamps, and not at the dynamo, the compounding of the dynamos being adjusted to overcome the dtrop in the line. ### The following tables shows the results of the test with only slight adjustment of the brushes: [table follows] ### The results obtained without any movement whatever of the brushes are as follows: [table follows] ### It will be seen in this table that only one reading was obtained where the volt meters varied, and this was for such a short time that reading could not be obtained on the instruments, and was only shown on the pressure indicator, and was no doubt largely due to the variation in the engine for a few seconds. ### Test was made for insulation of entire system from the earth, and showed a result, with portable bridge set, of 127,000 ohms, which we believe shows that the work has been well done in every respect. ### We also append hereto copies of one set of indicator cards, to show the general style of cards obtained. The number of cards taken as shown by the tables were averaged for the whole lot in figuring results. The copies attached to this report, though, show a fair average of them. ### Test was made for drop in line between the dynamos and the lamps. The specifications allow five per cent. The result of test showed a drop of about 2-1/2 volts; this was under full load. ### Although we have made a hasty review of the data obtained on this test, we believe that the main points we have specified fully cover the results obtained during the tst. We believe, too, that the test has shown that the plant has been properly installed, and fulfills all the requirements of the specifications, and we respectfully submit this report to your early and favorable consideration, and trust in return to receive an early acceptance of the plant." Very respectfully yours, C.J. Field [8 hand drawings follow in 4 pages]





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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
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