O RI GINA L PA PE RS COMMERCI AL DYNA MO DES I GN W I LLIA M L WAT E RS M E E H . , . , . En inccr in ( Mar : o Hi /x S eed M ac/tinn Westin nause Elec i g y f g p y, g tr c 65 u r r /zi E er N t o l lec Man actu in Co . rme / C c n ine a i na E f g fi y f g , o l rin /r u r C . and Co nsu tin En ineer Wa o se Ai , g g , g Brake and Canadian Westing/ww e Co t . F I R S T E D I T I O N NEW O Y RK. $OHN W ILEY 8c SONS LONDON: C HA PMA N 8c H A LL, 1.1m m 1911 COPYRIGHT 19 11 BY W I I W A T ERS LL A M L. n t kno w led e but i no ra ncc tlla t bc m o g , g , g C HA RLES DARWIN cfzm ma n a debto r to Ii i: ro u io n y p fe , ; b a l mend to e he p and orna ment tbcrcunto . Fu ncns BA CON 3 4 36 52 I NT R ODUC T I ON — Commercial Engi neering The nin eteenth century was nota s i ble for the achievement of the eng neer , and there is little doubt that the men responsible for this pioneer w o rk were engineers in i the broades t sense of the word . They were eng neers in their ability to manipulate the forces and materials of nature ; but they were also far- sighted and level-headed men of aflairs in their ap l preciation of the economic va ue of their work , and in the man a em en t . g of their projects These men , by their genius and i s h enterpr se , and by their hard common ense and solid ac ieve i ment , forced the world to recogn ze the engineer as destined to play a leading part in the future . Public attention became an d focussed on the engineer , numbers of men were attracted r to the profession , either through natural inclination or th ough hope of profit . But as was to be expected , a large percentage an d of these men were imperfectly educated , possessed only a an specialized talent in certain directions , without y of the broad minded comprehensive spirit of the pioneers . This change soon reacted on public opinion , and the engineer lost his high stand ing ; so that the public and the world of commerce came to re $ ” - gard him as a specialized crank , a species of high grade. artisan , w as who though useful enough in his place , devoid of any ability to take a sane and comprehensive view of a situation , or to man an age undertaking in which he might be interested . The com m ercial u world , though distr sting the ability of an engineer to hi s manage enterprises , came to realize more and more their iii iv INTRODUCTION f . o economic value and financial possibilities The result this was , that the enterprises which the engineering world proposed , gradually came to be exploited by business men , who had to o f n a greater degree the confidence the fi ancial powers . These to men , who attempted manage such undertakings , were usually o f n o t altogether ignorant the work they took up , and it is sur f E prising that this development produced indi ferent results . n in eers ff o ff o o f g , being e ectively cut fr m the commercial side their work , became narrower ; while the increasing specialization left the commercial men in still greater ignorance o fthe products they were handling , and their management became more and more wasteful . The inefficiency o fthis arrangement has gradually be come evident to all , and it is now generally recognized that the executive and commercial head of any large engineering enter prise must po s ess some engineering knowledge . It is also realized fo r that , given an opportunity a broader education , an engineer can be readily trained to become an efficient and high- grade com m ercial en executive , while it is almost impossible to instil an gineerin g knowledge into o n e whose training has been restricted f to . o are the commercial world As a result this , engineers being given opportunities to obtain a broader commercial education , and it is recognized in high financial quarters that in the future t hey will have to depend o n the engineering profession for high grade operating men in all engineering enterprises . Already we o f the n find engineers at the head a number of large concer s , and it is probable that the time is n o t far distant when it will be the exception to find the operation o f an engineering under taking in the hands o fany other than an engineer . —I Mr $ o hn I Be s . t . gg was my good fortune to work under f $ . o n e o Mr . ohn I Beggs , one of the first and the most prominent o f the commercial engineering executives in this country , at a time when I was so interested in purely engineering problems that I was in danger o f drifting away from broader interests . Fo r twenty-five years in active touch with the electrical engineer as o r ing industry , a manufacturer , as an organizer and operator o f public service corporations , obtaining his engineering and INTRODUCTION r commercial knowledge th ough hard personal experience , Mr . Beggs was pre-eminently fitted to guide and encourage the i youthful engineer . Continually mprovin g and rendering com m ercially practicable much of the apparatus used in connection s with electric lighting or railway intere ts , and doing this with o f n n s the purpose obtai i g re ults , rather than of being accorded o r n credit public recog ition , he was one of the first to realize that the engineer was destined to become the dominant i G i hi factor in large eng neering corporations . iv ng s young ' engineers a free hand in all branches of commercial and i n n neces engineer ng work , only guidi g and checki g them where sary , he developed organizations and men in a way , which , while r b it made the men his grateful and enthusiastic admire s , esta lished his reputation as one of the foremos t organizers in the engineering indu—stry , and left his mark on the methods and . s apparatus of to day In inscribing the e few papers to Mr . I i $ . I n ohn Beggs , am o ly tak ng an opportunity of express in g my indebtedness , and my appreciation of the education it w as to be in touch with him . I have entitled the papers $ n u Commercial Design , because engi eering questions of p rely academic interest are made subservient to those broader s n is ues , where desig and operation must be considered in their relation to the commercial success and future of the undertak ing . It is in this feature of my work that I have to ao in e c fiu n e . knowledge the of Mr Beggs , and to state that I have in a great measure to thank him for any small succes s I may have had . Histor o Pa e s — y f p r These papers , which have been written f r d s ix at di ferent pe io s during the past years , are the result of fifteen years ’ experience as a designing and manufacturing engineer in some of the most important electrical manufacturing E concerns in urope and America . They cover various subjects o f relating to the design electrical power machinery , in which I f happened to have been interested at di ferent times , and they are reproduced here in the hope that they may be more accessible , to any whom they may interest , than they would be in the pro vi INTRODUCTION ceedings of the various institutions . The student will find there is no lack of treatises on dynamo design by capable men , and this book makes no pretense to be a comprehensive work . It is f merely o fered as a supplement to such treatises , as a series of articles , which written by one who is actively engaged in prae tical manufacturing , may cover a few points of special interest s to the tudent or designing engineer , that could not be satis facto rily covered in a more general work . Decembe r, 19 10 . C ONT E NT S PAG E DOUB LE CURRENT GENE RATORS IN THE IR RELATION To DOUB LE CURRE NT SUPPLY PREDETERMI NATI ON o r SPARR ING IN D IREC T CURRENT MACHINES ROT ARY CON $ ERTERS AND MOTOR-GENERATORS SHUNT AND COMPOUND ROT AR Y CON$ ERTERS FOR RAI LWAY WORK — T HE NON SYN CHRONOUS OR IN DUC TION GENERATOR I N POWER STATI ON MO DERN DE $ E LOPMENTS IN SIN GLE PHAS E GENERATORS PERF ORMANC E SPE CI FI CATIONS AND RATI NGS INPUT-OUTPUT EFFI CIEN CY T ES TS DIREC T CURRENT T URBO GENERAT ORS COMMERCIAL ALT ERNAT OR DESIGN THE design of alternators has been treated times w ithout l i . a.