. Motion picture electricity. of all circuitswithin the building. Frequent examination should be made of allcontacts, fuses, and switches to insure minimumloss and to improve the operation of the lamps andapparatus connected to the system. Three-Wire Service requires the usual protecting,metering, and distributing devices—the same as for 2-wireservice, but in somewhat modified form, because of the 68 MOTION PICTURE ELECTRICITY fact that the 3-wire system has a third or neutralwire between the two outside wires, and instead of de-livering only one voltage it is possible to get two differentvolt
. Motion picture electricity. of all circuitswithin the building. Frequent examination should be made of allcontacts, fuses, and switches to insure minimumloss and to improve the operation of the lamps andapparatus connected to the system. Three-Wire Service requires the usual protecting,metering, and distributing devices—the same as for 2-wireservice, but in somewhat modified form, because of the 68 MOTION PICTURE ELECTRICITY fact that the 3-wire system has a third or neutralwire between the two outside wires, and instead of de-livering only one voltage it is possible to get two differentvoltages from a 3-wire system, which is often of advan-tage, and besides, it makes it possible to carry a heavierload with smaller wires, switches, fuses, etc. TOLINE T OUTSIDE WIRE OUTSIDE WIRE LINE SWITCH 000 [j [] [j 1« U 4 ioi. OOOO CIRCUIT FUSESCIRCUIT SWITCHES TO CIRCUITS 110 V. 220 V. 3 WIRE FUSES- f ig. 32 3 WIRE SWITCH- ©rt+k© rr. ?oe-e/Q*oa-Bi(^«-/ 0- J • Q*e-ao- 8 WIRE CIRCUIT 6 . 11QV. FOB STAGE SP 110 V. 4. U ii~I~iiii [i 0 Fig. 32 is a diagram illustrating a typical 3-wire in-stallation, including the following: Three-line fuses. Three-pole line Three-wire panel board. MOTION PICTURE ELECTRICITY 69 The line fuses are connected to the 3-wire lines com-ing into the building. On the outside wires, there is usu-ally a pressure of 220 volts and between the neutralor center wire and either one of the outside wires thevoltage would then be no. The wires leave the switchand go into the meter. From the meter three wires arerun to the distributing panel board, which is clearly il-lustrated in Fig. 32. You will note that the three topcircuits on each side of the bus-bars deliver no volts,because they are connected to the middle and one ofthe outside bus-bars alternately. The two lower switches,however, are connected to the outside bus-bars only,therefore the voltage available on the two lower circuits is220 as may be desired for large ventilating motor
Size: 3065px × 815px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1900, bookdecade1910, bookidmotionpictureele00hall
