| lh Ih Eeal nm Se LIBRARY Michigan State University MSU LIBRARIES A RETURNING MATERIALS: Place in book drop to remove this checkout from your record. FINES wil] be charged if book is returned after the date Stamped below. Test of a Single Phase Commutator Motor A Thesis Submitted to The Faculty of MICHIGAN AGRICULTURAL COLLEGE Candidate for the Degree of Bachelor of Science June 1916 THESIS PREFACE The purpose in running a test on the 1 H-P- Alternating Current Commutator Motor as a thesis was, primarily, to get all of the data possible pertaining to this machine and, secondarily, to become entirely familiar with this type of electrical apparatus. A study has been made of its action under various loads, data taken and curves plotted from the calculated results, thereby giving a clear and complete record of the work takeh up. At first the question arose as to the best method to be used in making a test of this nature- The writer finally decided to use the prony brake throughout - The brake is capable of very fine adjustment which was the main reason for selecting this method- Diagrammatic sketches have also been made of the motor and control box thereby illustrating the construction and operation of each. Le Fe Ce 94898 The first thing necessary, before the writer was able to start the testing, was to construct a prony brake. The construction of this brake is shown clearly by the accom- paning drawing. The motor iteelf consists of a main field winding and a compensating winding on two of the poles. It is operated entirely in connection with the controller as shown in the sketch. A pulley,6" X 4", was already fit- ted on the shaft. A voltage regulator was placed directly in the line. This regulator was necessary as the motor was rated to run on a 110 or 220 volt, 60 cycle circuit and the impressed voltage varied considerably from this. The source of E-M.F. was a rotary convertor. This rotary fluctuated in speed because of the fluctuation of the voltage on the D-C- side, this in turn caused the voltage to fluctuate on the A-C- side- To remedy this difficulty was beyond the control of the opsprator. In spite of the fine adjustment obtainable by the voltage regulator the impressed voltage varied a slight amount. This in turn varied the speed of the motor so that it was necessary sverything to be stable when the readings were taken. With the bringing out of a motor of this nature a wonderful work was accomplishek- It is true of this machine, as with many other inventions, that when it first came out it was rather a crude piece of apparatus but by encountering difficulties one after another and overcoming these by various devices, it has grown today to be a wonderfully useful machine. Improvements have by no means stopped as remarkable steps are being taken at the present time. It is remarkable because of the fact that the same machine can be made to act either as a series or a shunt motor with but very slight alterations. The fact of its great flexability makes this type of A-C. motor exceptionally valuable- The developement of this line of apparatus has been slow but at the same time steady. It has been changed from the shunt variable speed motor to the constant speed motor which is desireable in many cases. It was later superceded by a brush shifting motor of double yoke construction which did not prove very satisfactory, but found a good market. A little later this type gave way to the single yoke construction and the sliding contacts were eliminated. Following this were other minor internal changes which tend toward improving the power-factor, torque etc. LIST OF APPARATUS USED MOTOR: G. E- Single Phase Commutator Motor. type RI, form A, amps 10-4 / 5-2 : hp. 1, speed 1710, cycles 60, volts 110 / 220. CONTROLLER: Rheostat, Fort Wayne Electric Works. CR. 172, cat. 114729, type RI, hp + l, cycles 60, volts 110 / 220- WATTIZET ER: Weston Portable Wattmeter. max capacity 25 amps. high range in volts 300, low 150. “ watts 6000, " 3000. model 16, number 4995. CURRENT TRANSFORMER: Weston Switchboard Current Transformer. model 236, type 1, No,550, amps 25 to 5, line voltage 2200. frequency 25 - 125, watts 5. AXMDIET ER : Weston Electrical Instrument Co- model 155, range 5 amps- No, 888%9- VOLTMET ER; Weston Electrical Instrument Co. model 156, range 250 - 500, No- 6822. VOLTAGE REGULATOR: =- Constructed at M-A-C. for thesis. PRONY BRAKE:- As shown in this thesis. SCALES:- Platform scales, range 5# on arm. TACHOMETER: = Liquid type, range 2000 R-P-M- No- 489. SYMBOLS USED L ap 42 oe oe @ ® @ OBO OOO HBOC © 8HBHABAMB#E®*#S*S®: EB eannnnnccnnnnnewnnnnnnsnennae $f anon2-----2------- ~~~ eee T sana ccennwennnnannmanannannne HePe eanacnnwmwnnenacesanweeeoncen Npe enn nsenewesonaeanccncanece Inst. caaananannnwnnanacnnennee NOo cuananeneesosnoeowonannnane Const. canqnnnnnnenncenaeseonne G ewww nnn nn men ennceneneennnnnn Rdg, eonwcnnnnnnennnenncennaene PePo ewnannnacanneenssonceseann EPL. wmmmeneceneanensennceoncna RePeMe eanneanaanncanennonaceoa Yo annnnaneennnnnnncenmnneononn Welle eancennnnnnwenannennwennen Col. enmnnannnaneennnneecscennn Velfe eanmmcanennnnnnncnannnnennnn AcMe emmmenanecmnnaasennscnnane Re seem nwnenannnannweweneneanece Deg. onnnnwwnnennenencnnecsenne Ce SS C20 HWBELOOOSEHISSE SESW current. volts. pounds weight. torque. horse power. horse power. instrument. number « constant. psrcent. reading: power factor: efficiency. rev- per- min- watt. | wattmeter- current transformer. volt meter. amneter. resistance. degree. | centigrade. BIBLIOGRAPHY Standard Hand Book oq«s-nsseess--e"= Sect-7 = 286 = 514- Sheldon and Mason ------------------- Page 262. Essentials of Elect. Ing. e«=-------~ John Fay Wilson. Hawkins Electrical Guide eueennee-ee- Hawkins. Alternating Currents e<-----<----"---- Jackson. page 874- A. C- Motors eeeeesee---- onceecenenonan McAllister. Hleotrical Machine Design «esee----r> Grays | A. Ie Be Be enewnneencaccnnccccessne= Vol. XXVITI-1909- BR cnn wnmn em eeeewneewnnenn= May, 1915. Theory of S- P- Co Mo eenennenceen--- F- Creedy: The Meoctric Journal ceesesessecerss= Maroh, 1916. Cold Resistance Measurements The fall of potential method was used throughout in measuring the resistance of the different circuits. | Readings of the voltage across the winding and the amperes input were taken as shown in the following tables. Cold resistance of the Inst- No- Const. Cold resistanoe of the Commutating winding at 22-2 deg. C. Inst. No. Comst.- E 6792 80 1-55 2°20 2-70 5-355 E 6792 °55 80 095 1-20 1-40 2195 -60 1-17 1-70 2°07 2-50 I 2195 1-20 1-75 2°10 2°70 5-20 Ave.=3 Ave.= Stator winding at 22.2 deg. C. R 1-330 1325 1-324 1303 1-340 1-324 R 458 ©4577 0453 -438 0434 448 Cold resistance of Rotor winding at 22. 2 deg- Ce. Segments l1- 52 corrected computed E E I R Inst- No. 5668 2193 Const. 202 1 2°50 1-20 «050 0416 4-00 1-80 e080 ©0444 4.50 2:13 e090 0422 6-00 2078 e120 ©0436 7-25 30 0145 0439 Ave-.% 0431 Segments 1-53 «50 60 °010 01668 1-00 1°23 °020 01628 1-80 1-80 «030 «01660 2-00 2°55 e040 ©01700 2020 2-779 044 -01592 Ave-= .81650 BRAKE TEST A brake test on any motor is the operation necessary to find principally the H-P. output of the machine. In connect- ion with this it is desireable to know the H-P- input, torque, % slip, % power-factor and the % efficiency. To obtain these quantities it is necessary to place suitable instruments in the line, the readings of which will, either directly or indirectly, give the results wished- In this test a voltmeter, ammeter and wattmeter were placed in the circuit, connecting all in the usual way- For the purpose of getting as accurate readings as possible a, 5 to l, trans- former was put in the line- Because of this much closer readings of the instrument were possible than before, as this meter read only five amps for full scale deflection. The voltage and frequency were kept constant at all time. From the instruments the operator read the volts, amperes input and watts. On one end of the brake arm was constructed a knife edge exactly 1-5 feet from the center of the motor shaft and supported on a platform scale- The point of support was in the same horizontal plane as the center of the motor shaft. This scale was accurately balanced with the motor at rest. After the motor was running the weight was advanced on the scale arm by increments of 1/4 pound each. At each new position the scale was balanced by means of tightening up on the brake band- Five tests were run in all, one on each of the following points;- Rel, R-3, R-6, R-9, R-11. All readings were taken at each change of load and the follow- ing results were computed from, the curves were plotted as shown in the succeeding pages. Formulae: HeP-Input = watts input 746 Torque =weight on brake arm x length of arm in feet = ft- lbs. HeP-Output = 2"i win 335000 Where w = # wt- on arm. " 1 = length of arm in ft. " n = R-ePeM- of motor % Slip = 1800 - R-P-M. x 100 1800 o % PF. = cos @ = watts input x 100 BeXIe % Eff. = H-P-Output x 100 H-P.Input Brake test with regulator arm on contact point R-l. Meter # Const. “3 HO Pm GN! Rdg -No. 2H Om GID Input 268 455 e615 e805 1-005 1-180 1-490 Test Data Wt .# NORM RrrRrOOO Volts 6822 1 110 110 110 110 110 110 110 Anps 8892 5 -90 1-06 1-50 1-51 1-80 2°04 2-57 Motor stopped Calculated Results Torque 0-000 0-750 1-125 1-500 1-875 2°200 2°625 Hp ° Output e000 e207 328 407 2453 0493 -510 Slip 0-01 7-78 14-70 20 -80 29-40 56-10 48.90 faite 4995 1 20 054 046 60 °75 -88 1-11 % Pp.F. 40-4 58 5 64.2 72-4 75-7 78.4 78-7 RePM. 1790 1660 1535 1425 1270 1150 920 yA Err. 0-00 58-10 51-70 50-60 45-20 41.80 34-20 Nae ee Brake test with regulator arm on contact point R-3 Meter # Const. z ~~ ODDQIMAAH KDE! Rdg -No- 0002 OF OD H ~ Input 268 -4350 617 -713 -912 1-070 1-245 1-450 1-690 2-060 Test Data Wt # Volts 6822 a 0-00 110 0-50 110 0.75 110 1-00 110 1-25 110 1-50 110 1-75 110 2-00 110 2.25 110 2-50 110 Amps 8892 5 80 1-00 1.22 1-45 1-60 1-85 2°15 2°48 2°82 5°63 2:75 Motor stopped Calculated Results Torque 0-000 0-750 1-125 1-500 1-875 2-250 2625 3-000 5-575 3-750 Hip- Output 000 244 -544 -435 -514 -582 °615 -640 629 478 isp 0.84 5°50 10-60 15 -50 20-00 24-40 31-70 357-80 45-60 62-80 Bates 4995 1 -20 32 -46 57 -68 80 93 1-08 1.26 (31.54 PF. 45.5 58.1 69-6 71-5 77-0 78 -8 78-8 80-3 81.2 77-2 R-P-M. 1815 1705 1610 1520 1440 1560 1250 1120 980 670 ee. 0-00 56-70 61-00 56 -40 54.40 56 -00 49.40 44 -00 57-10 29°20 ' feauune ca a) a ae E SRSESS ANT SHL/ A sy XN ot PTS TS, 3 8 5 ad { | 2 | t c ' Lh) TUT Me a aaa ay BS By ee ee eee YOLOW WD at a eee | | } } | | : j } |LAIOG NO| WHY HIIM Hee 1h MIA TE eae et eho) i bescear ses esl rx ae) “T0087 06 i eae Lire Lf a Oe a Ape EPO) t ' ; i} } ask S3gtsecses A i | 1 OC@7 OO ist tl / yA j YOLILK A? YIM Brake test with regulator arm on contact point R-6. Test Data Watts Rdg-No. Wt .# Volts Anps Watts R-P-M. Meter # 6822 8892 4995 Const - 1 5 1 1 0-00 110 0-80 «20 1840 2 0 -$0 110 1-03 36 1730 3 0.75 110 1-20 246 1670 4 1-00 110 1-39 56 1590 5 1-25 110 1-54 °65 1510 6 1-50 110 1-70 74 1450 7 1-75 110 1.94 86 1390 8 2-00 110 2022 96 1310 9 2-25 110 2-55 1-12 1225 LO 2-50 110 2-90 1.28 1130 11 2-75 110 3-32 1.40 980 5-00 Motor stopped Calculated Results Rdg. Hp. Hp- % % No- Input Torque Output Slip p.F. Rf. 1 -268 0-000 -000 2022 45.5 0-00 2 ~482 0-750 246 3.89 63-6 51.20 3 °617 1-125 0357 7.23 69-6 57.80 4 «750 1-500 454 11-66 13 3 60-50 5 °872 1-875 565 16-10 176.7 65-00 6 -993 2-250 621 19.44 719.2 62.50 7 1-150 ., 2-625 -645 22.80 80-6 60.40 8 1-286 3-000 ©7717 27-20 77-8 | 58.20 9 1-500 3-375 786 31.95 80.7 §1.50 10 1-715 3-750 -806 37-20 80-3 47.10 11 1-878 4.125 847 45 .50 84.0 45-20 | \ i as akan! Pesaran } / Dahle ! { | | ; | | | ) zy My, Ny 6 g i I cE }; } eeeee i Rheuwec rad es bunie let | / Te dakid Lebel BN) ; Sas ewl: - R : SN ebeSS ey | irene ' | : | a Ai — — . — Se | a a ete aay | | | fe . 2 | ese | } | . EE eked rab be Peeve) Las my Sa Dee BOY. i | G i | / Lat dol ee | | | | ea os i RRS a f | ! | el da a> | ; | 1 : ! | ' ! } | { j , | | | | ~ ne = i os — 5 8 CxEeey tee = ~ as ae | | | ; Mma Lod NO | YOLOW 0 SPAHAD } rise fe pepe ay e + ot is S N OTe At) Wim Pag BS : Ny PO aaa ASP ET) eke rhe : sespsaeets 24 i | aagtayss rebs7 Se a 10097 00s : : {. Tel ue ay Bet Sere pees erat Beep i Ne ee a nae Brake test with reguiator arm on contact R-9. Amps 8892 Fs) °80 90 1-10 1-30 1-45 1-61 1-81 2°03 2°24 2-54 2-81 3-18 35-58 5-94 Slip -35-61 1-39 4-72 8-62 11-10 13-90 17.77 19 -45 22-80 29 40 27.80 53 +50 37-80 Test Data Rdg -No- Wt -# Volts Meter # 6822 Const. 1 1 0-00 110 2 0.50 110 3 0.75 110 4 1-00 110 5 1.25 110 6 1-50 110 7 1.75 110 8 2-00 110 9 2-25 110 10 2-50 110 11 2-95 110 12 3-00 110 13 3.25 110 14 3-50 110 53-75 Motor stopped galodlates Results. e De Hp- No- Input Torque Out put 1 268 1-125 -860 2 0443 e750 0204 3 °376 1-125 567 4 ©9724 1-500 ©470 5 e -8350 1-875 -570 6 0937 22250 e664 7 1-085 2-625 -740 8 1-260 5-000 -830 9 1-380 503575 °892 10 1-530 3-750 -945 ll 1-700 4.125 1-020 12 1-850 4.500 1-028 13 2-010 4.875 1-038 14 2-200 5 -250 1-110 43.80 Watts 4995 1 e20 235 -45 54 262 70 -81 94 1-05 1-14 1-27 1-58 1-50 1-64 P.y. 45.5 66 -6 77-5 78-8 77-6 79.1 81. 84.3 83-8 81.8 80-8 78 -O 76 -2 75.8 R-P-.M. 1865 1775 1715 1645 1600 1550 1480 1450 1390 1525 1300 1200 1120 1110 ) Ws aa 1 - oe _ Seem WY P41 Nk sy Paces eeageasee } } | 4 VE eae ! ESSLOS4PSgeeeEgt | AUSSTOST “OETEC r ; Ne | Ree aL Arh ie | -{ een Serbessee 3 os R ghar sae Rebeaness . ata: | SRUGEESSESGUESSCNERG | AUREEST (J cEUESDATE a . | 3 | ine ess le me") snag Y PIL) Hae Le LR REE MLA ELI i ie) U, } ai : chal eae i baeaaa a anced FSU . ; rs aad I SETSEBISE ie | | | | | | rus Wt } *t a Tale A t i 7 : ’ | : i > Y aWlog NO Wa HLIM\ | : Yor : ae Brake test with regulator arm on last contact point. Meter # Conste Rdg-No- OONOHOO ONE Test Data Wt.# Volts 6822 1 0-00 110 1-00 110 125 110 1-50 110 1-75 110 2200 110 2025 110 2-50 110 2-75 110 3.00 110 325 110 3-50 110 3-75 110 4-00 110 425 110 4-50 110 4.75 110 5.25 110 Amps 8892 5 1.35 1-43 1-55 1°68 1-80 1-91 2004 2014 2032 2046 2056 2076 2089 3007 3-18 3037 3-60 3077 5-91 Calculated Results Hp- Torque Output 1-125 1-500 1-875 2200 20625 3-000 523575 3-750 4.125 4-500 4.875 5-250 52625 6 -000 6-375 6-750 70125 7 +500 7-875 ©4352 5635 628 °750 e810 °892 -9635 1-035 1-080 1-157 1-205 1-215 1-210 1-280 1.271 1-250 1-220 1-258 1-200 & Slip -18-52 -9 016 wens 5028 10-00 135-32 16 -68 19.44 20°60 25-00 27280 32-50 57-25 37-70 41.60 46 -20 50-00 Sl -O00 55-60 Kiloe Watts 4995 1 ¢50 ° 56 066 075 80 90 99 1-05 1-14 123 1.27 1-57 1Le42 153 1.58 1-62 1-74 1-82 1-85 of /? P.f. 40 -500 72100 77 «400 81-800 80 --700 85-500 88-200 89-000 89.100 89 -200 90-800 90-200 89 -500 90-800 90-400 87-600 88-000 87-600 87-600 Re Pete 2150 1965 1760 1705 1620 1560 1500 1450 1575 1350 1300 1215 1150 1120 1050 970 900 880 800 Err. 80-@ 75.0 10-9 74.9 1507 74.0 126 1307 70-8 1001 70.8 66.3 63.7 6307 60-2 57.5 52.3 51.5 48.5 yp ha