[Electric engineering.] . f different forms, some of them beingarranged so that their operating handles interlock so thatthey may be operated singly or together in any desired com-bination. Dimmers are, of course, connected in series withthe circuits that they are intended to control. INTERIOR WIRING. 28 WIRING FOR SPECIAL PURPOSES. 10. While in most work of a permanent character thecloset system of distribution, with very slight drop in thebranch lines, is the proper system to adopt, there arespecial conditions that sometimes make it desirable to installwires for a very low price, for tempora
[Electric engineering.] . f different forms, some of them beingarranged so that their operating handles interlock so thatthey may be operated singly or together in any desired com-bination. Dimmers are, of course, connected in series withthe circuits that they are intended to control. INTERIOR WIRING. 28 WIRING FOR SPECIAL PURPOSES. 10. While in most work of a permanent character thecloset system of distribution, with very slight drop in thebranch lines, is the proper system to adopt, there arespecial conditions that sometimes make it desirable to installwires for a very low price, for temporary or occasional such installations, the efficiency is of comparatively littleimportance, but the proper regulation and uniform voltageat the lamps are as important as in permanent work. 11. Let us take a case, such as the installation of a thou-sand 8-candlepower lamps for decorative purposes aroundthe cornices of a building at a fair, where the wires will beup for a few days or weeks only. All the lamps are to be. Fig. 2. burned at the same time. In such a case, it may be eco-nomical to allow as much as per cent, drop on the linesand use 100-volt lamps on service. We willrun but one pair of feeder lines around the building, a dis-tance of 1,000 feet. We desire to have the drop on theselines such that we will have 100 volts at any point between § 28 INTERIOR WIRING. ?? them and volts at the terminals. This can only beaccomplished by running the lines in opposite directionsand having them change in size often enough to securepractically uniform drop per foot. Fig. 2 (a) illustratessuch an arrangement, and (b) shows the same thing drawnin a straight line instead of a square. This is sometimescalled the anti-parallel method of feeding. 12. There will be a lamp for every foot. There will berequired 10 branches of No. 11 wire, with 25 lamps on eachbranch, as sIioavii in Fig. 2 (/?). Weather-proof wall recepta-cles will be used. The total length of wire
Size: 1678px × 1490px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookidelectricengi, bookyear1902
