. The practical telephone handbook and guide to the telephonic exchange . g. 296 showthe wires radiating in horizontal planes to the horizontal tabstrips, the horizontal bars h v forming a shelf on one side forthe support of these wires. The iron rings r r have an insulatingcovering of vulcanite to prevent possibility of earthing. Testing at Arresters.—In localising faults, etc., it is sometimesnecessary to make connections at the arrester strips. Forthis purpose a special testing shoe is used, shown in Fig. 292,this being joined by a 4-way cord to the test clerks heat coils are first
. The practical telephone handbook and guide to the telephonic exchange . g. 296 showthe wires radiating in horizontal planes to the horizontal tabstrips, the horizontal bars h v forming a shelf on one side forthe support of these wires. The iron rings r r have an insulatingcovering of vulcanite to prevent possibility of earthing. Testing at Arresters.—In localising faults, etc., it is sometimesnecessary to make connections at the arrester strips. Forthis purpose a special testing shoe is used, shown in Fig. 292,this being joined by a 4-way cord to the test clerks heat coils are first withdrawn from the arrester springs, andthe test-shoe is slipped over so as to make contact with allfour springs of the arrester. This is rather a slow method of testing, but as only a smallproportion (about 5 per cent.) of the faults need to be tested 288 PRACTICAL TELEPHONE HANDBOOK in this manner the small loss of time is not of much conse*quence. Intermediate Distributing Frame.—This is situated betweenthe main frame and the switch-board. It is built similarly. Fig. 292.—Testing Shoe to the main frame, but need not be quite so large, as it is onlynecessary to provide for the lines actually to be fitted on theswitch-board. It should, however, be built for the full capacityat first, as it is difficult to enlarge after installation. The ter-minal tabs on the side connected to the main frame are arranged
Size: 2328px × 1073px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
