[X001M2AH], Letter from Wilson Stout Howell to Edison Electric Illuminating Co (Mt Carmel), May 23rd, 1888


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[X001M2AH], Letter from Wilson Stout Howell to Edison Electric Illuminating Co (Mt Carmel), May 23rd, 1888

Editor's Notes

[letterhead of Edison Electric Illuminating Co., MT Carmel, PA,] Gentlemen: ## In response to your request, I have inspected your Edison Station at Mt. Carmel and beg to present this my report of its condition Electrically:## First:- The dynamos, two of type "S" were found in good conditions, but dirty. The commutator on the "B" dynamo should be turned off true and a new set of brushes provided. In ordering brushes, order them of extra lengh. The magnets of the dynamo on the "A" side were reveresed causing that dynamo to send out its current in the oppisite direction to the "B" dynamo, producing the same effect as is known as "breaking down" the three wire system, amking it necessary to increase the pressure (E.M.F) at the dynamos thus defeating the prime object of the three wires system, by increasing the loss of energy on the conductors; preventing proper regulation and limiting the range of distribution to short distances. The increase of pressure necessary at the dynamos made the brushes work badly; heated both armature and commutator unduly and required much more power as shown by the high boiler pressure necessary when the dynamos were working opposite each other. ## To remedy this defect, I demagnetised the magnets of the "A" dynamo and charged them correctly, which restored to them their original polarity and allowed them to work in series giving on the mains 224 Volts between the outside wires.## The effects of this change were noticable; the steam pressure was carried 15 lbs., lower, the engine worked easier; less coal was required; the dynamos worked with less spark and cooler; the dynamo regulators were turned back 50% lower, the lamps were uniform. ## I placed an ampere meter in circuit with dynamo on "A" side and found the highest load that night (may 17) to be 80 amperes or 40% of its full load and by comparison found that the other dynamo was doing about 15% less work, leaving ample capacity to increase the number of lamps in use 100% providing your engine and boiler are large enough. ## The bearings of the dynamos ran cooler than in the average of central stations. ## Second:- (Electrical Apparatus) -- In this, your station is poorly equiped. You have no change over switches (No. V 65) These switches are built on to the later type of Edison Dynamos and are useful in throwing both dynamos on one side of the system, which is necessary in cases of burning off heavy crosses; breaking down of one side or a serious over-load to one side where one dynamo can not carry all its lamps; for throwing in a spare machine and various cases of emergency.## The ampere meters in use, (No. V 67) are of an old type not now recommended, and reliable only if they are re-standarised at least once in six months. They should be replaced by a pair of No. 337 Ampere Meters of 200 amperes capacity. These should be placed at least eight or ten feet from the dynamos. ## Your break-down switch is too light to answer in heavy loads as it is not capable of carrying over 200 amperes without heating. No. 121 would answer much better and not heat up with 400 amperes. While the one in use may answer all your present needs it would be wise to get a No. 121 if a new station is built. The old neutral Ampere meter which burned out, was destroyed because of a bad contact; the copper rod was not firmly held by the clamp; this had joint offered such resistance to the passage of the current that much energy was lost at the point, appearing as heat. This is the case where any of the conductors are too small or the contact is bad. The remedy is to provide conductors and apparatus of ample size and make contacts clean and tight, soldering all joints where practicable. ## The pressure indicators are of the latest and best pattern are set to burn the lamps about 2 Candle Power high when needle is on zero. The pressure wires (the small iron wires leading from the end of the feeder at Oak Street) are of bare iron wire; they should be insulated. I would advise that they be replaced by No. 14 B.W.G, iron wire K.K., insulation. This is a very good cheap wire made by Holmes, Booth & Haydens, New York, costs about $35.00 per mile. ## Third:- (conductors) -- I haverecommended that the safety leads be removed from the neutral wire of the feeder and if any are in use on the neutral mains that they all be removed also, their pressence is a source of danger to the lamps in case of their burning out. ## I also recommend that the neutral mains and the neutral feeder be connected at two points on the line and that the position mains be connected to each other and the negative mains be connected to each other where two sets of mains run on same pole as is case on one street in Mt. Carmel. ## Your conductors are of sufficient size to more than double your present number of lamps, especially if the new Edison Lamp is used in which case you can run 800-16 Candle Power lamps with present plant. ## Your service wires seem to me ot be quite small although I made no special inspection of them because of inclement weather; many of them are bare. This is not considered good practice and should be discontinued. ## In wiring new customersm you should run three service wires in all buildings where six or more lamps are used, dividing the lamps equally between the "A" & "B" sides. ## Very respectfully yours, Wilson S. Howell ## Report on Edison Station at Mt. Carmel Pa. May 17th and 18th 1888.




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