[X001M2AU], Letter from Wilson Stout Howell to Electric Light Company of Atlantic City, May 1st, 1889


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[X001M2AU], Letter from Wilson Stout Howell to Electric Light Company of Atlantic City, May 1st, 1889

Editor's Notes

Gentleman, In response to an order from your board of directors transmitted by your superintendent I have visited your station and report as follows upon the general condition of your Edison plant and the changes made or advised. The most serious fault existed was the abnormally high pressure on the bus. With a load of 350 amperes on each side of the system the bus pressure was 138 volts and 142 volts. Your dynamos were built to give 125 volts at full load and at normal speed but as they ran below normal speed they could not carry the full load at the increased pressure. Skipping belts added considerably to the fault increased the skipping of the belts increased and made it more difficult to keep the pressure up consequently it was necessary to run all your dynamos (two #12 and four #10 dynamos) to carry a load of 350 amperes on each side of the system, when it should not be difficult to carry 640 amperes on both sides of conditions were normal. The cause of the abnormally high bus pressure was great loss of pressure between the bus and the feeder end, due to too much equalizers resistance in standard feeder and too high pressure at feeder ends, (116(-) & 119(+). To correct these faults I took all resistance out of circuit of the standard feeder and brought the pressure on the feeder ends to 116 volts on both sides, which reduced the bus pressure to 126 volts on positive side and 122 volts on negative side, an average reduction of 15 volts a saving of about 15 horse power of electricity with a load of 350 amperes. The immediate results of this lowering of the bus pressure were to enable you to carry the full load on the dynamos without shortp-circuiting the regulators a visible reduction of coal consumers, a decrease of heating of coiils of equalizers and a decided improvement in the regulation of the pressure at the feeder ends. These advantages can be increased by a gradual reduction of your pressure to 112 or 113 volts at the feeder ends by moving the slider of standard indicator as mareked a scale. After reducing the bus pressure I found that the feeders were badly out of balance and that the regulation was seriously affected thereby, I measured the current on each side of each feeder at full load and found them as follows: #1 feeder had 130 amperes on + side and 85 amperes on - side #2 feeder had 70 amperes on + side and 60 amperes on - side #3 feeder had 35 amperes on + side and 10 amperes on - side #4 feeder had 55 amperes on + side and 55 amperes on - side #5 feeder had 5 amperes on + side and 36 amperes on - side #6 feeder had 10 amperes on + side and 60 amperes on - side At the same time the balance ampere meter showed that the station load was well balanced, which illustrates that it is a very bad plan to attempt to balance a system by using an ampere meter on the neutral bus. [star symbol] There is but one correct place of balancing and that is to balance each and every customer on a three wire service or with two lamps in series and two hundred volts. It should be your rule to run three wires to every customer having one hundred candles-power or over and balance his lamps as used between the two sides of the system. If you drive motors you should under no circumstances serve current to any motor larger than 1/4 horse-power unless it is wound for 220 volts. [Star text, insert at symbol] The only apparatus which wil naturally aid you in properly balancing your system is an ampere-meter placed on the positive and negative of each feeder. They would show you at all times the load on any feeder and how that load was balanced. All modern stations are so equipped when constructed and many of the older ones are adding this feature to their apparatus. In balancing a system having two-wire services, the first and most important step is to balance the mains in each locality. This local balance is of the greatest importance as it affects the quality of the light and the life of the lamps. If you have a number of two-wire services leading from one cross-arm you should balance the lamps at that point, not the total number of lamps connected but the average number in use at one time. If all your mains are balanced in this manner and kept balanced as customers are added or cut off you will have as good results as can be had with two-wire services. With two-wire services a good local balance cannot be maintained without "eternal vigilance" on the part of the superintendent. Any one who has ever operated an Edison three-wire station with all customers with all customers carefully balanced on three-services and motors built for less than 220 volts. If put in charge of your station would not rest till he had balanced every customer. It is difficult for one who has not operated such a system to appreciate all its advantages of economy, ease of operation and constancy of light. Too much cannot be said on this subject of careful maintainance of local balance as it is a point of first importance. With a good local balance your mains your feeders and your station will be balanced. The importance of balance decreases as we approach the station. First in imporance is the balance of each customer. If the customer has many lamps or his lighting is widely distributed over a large area his wires should be balanced in every section or division of the jouse mains. Next in importance is the local balance, or balance of each cross-arm, the balancing of each main fallows as the local balance improves and while in itself a decided advantage it is never as important as the local balance. The balancing of the feeders is still less benefit and the station balance of very little account. Suppose a station with tin feeders, each feeder serving current to four mains, imagine each main to have three amperes more on its positive side than on its negative side, each feeder would then be twelve amperes out of balance and the neutral ampere meter in the station would show 120 amperes out of balance. Such a state of affairs would have been considered very serious a few years ago and the average station manager would hasten out on the line and by so doing in nine case of ten he would destroy the local balance at the points where he made his changes. His fancied balancing of the system would be a myth. He had been taught to balance his system in the manner from the start and it was not fault that he had been working "hind side before." In order to get the best results from your feeders are the feeder ends should be connected through heavy main and all mains should be bridged to each other. Your system is well bridged except on the Board Walk where there are three mains whose ends are close to each other but not connected. At these ends of mains the pressure was found as high as 115's volts and as low as 109 volts on the positive side of difference mains. This was due to bad balance but had the ends of these mains been bridged the pressure and balance would have been greatly improved. The mains on the Board Walk should be at least #2 B.W.G. where you have only #6 A.W.G. and these mains should be connected so as to form a bridge between the mains on Sea Side Ally, So Carolina Ave, New York Ave, Kentucky Ave, and Illinois Ave. The insulation of this main should be of R.R. or its equavalent and all service wires and indeed all wires on the Boardwalk should be of the same grade of insulation. In order to balance the temporary customers on the Board Walk I advise that lamps be wired two in series with 220 volts pressure. I consider your plant in very good condition generally and in need of very little charge to make it equal to any of its class. The dynamos galvanometer has been connected up so as to perform its functions and is a valuable aid in throwing in dynamos. Your indicating and regulating apparatus is of good type and in good order. I believe that, with heavy bridges between the ends of all your feeders and all your mains well balanced locally you could operate your station without equalizers. I have made a charge in #5 feeder, which delivered current to the mains at the corner of Pacific Ave and Baptist Ally. This feeder carried a very small load and was composed of two #00 A.W.G. copper wires on each side. I took one wire out of each side back as far as the corner of NY Ave. and Pacific Ave, and ran these two wires down New York Ave t Board Walk to feed that vacinity. Pressure wires run from these two wires back to corner of New York Ave and Pacific Ave where they join the original pressure wires of #5 feeder. Thus #5 is a split feeder having its ends very far apart, and pressure wires taken from each end. This charge should help the lights on the Board Walk and gain you all the custom in that district. With the balancing of the system locally and the consequent improvement of the light the demand for Edison light will rapidly increase and you will be obliged to meet the question of additional dynamos capacity in which case I should advocate a pair of #20 Edison dynamos to be run by your Ball engine. Sell one pair of your #10 dynamos and use the engine which ran them for the arc dynamos now on the Ball. In ordering additional dynamos specify that they shall have the dynamos changing switch on the headboard. All your dynamos appear to be in good order the commentators are especially well cared for. I do not consider the wires safe which connect the regulators to the dynamos they are not well insultated and are liable to eat off and open the magnet circuit which would if it occurred while running two dynamos in multiple short circuit your system. These wires should be replaced by R.R. wire run on porcelain knobs, in plain sight on the ceiling of your engine room. If you can obtain the right of way for a line of poles from your station to Atlantic Ave. along the Canadian + Atlantic R. R. tracks you will be able to shorten your feeders #4, #5, + #6 about 800 ft. which will give you considerable large size wire to use as heavy mains between feeder ends, which acting as feeder bridges or balancing wires would enable you to keep the equalizers out of circuit or to dispense with them entirely. It is not considered good practice, for stations which run only twelve hours daily to switch the current into the lines at full pressure but to close switches and adjust brushes before "bringing up" the magnets. By this latter method you are made aware of a cross on the line before any damage is done to brushes or commutators. Your lineman should brighten the contacts on all poles line safety catches and holders and keep them bright or the sea-air will oxydise them so as to interfere with their usefulness. Some companies have adopted the rule that all temporary or irresponsible customers shall pay in advance. Would it not be well to try this in Atlantic City. I shall be glad to answer any questions concerning your plant which may arrive or to advise with you upon future extensions. Yours very truly, Wilson S. Howell Report of Wilson S. Howell to Electric Co. of Atlantic City May, 1, 1889 Electric Light Company of Atlantic City, NJ, Edison System of Incandescent Lighting American System of Arc Lighting




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