We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
ELECTRICAL CONDUCTORS 87
Never fuse a motor circuit above the rated capacity of its circuit wires. The Board of Underwriters permit the motor or motors to be fused at 2? per cent above capacity but this requires that the motor circuit wires have a capacity of at least 25 per cent above the equipment they serve.
Fusing Projector Circuits
(82) Projector circuit wires and switches should always be of sufficient capacity to carry current considerably in excess of the maximum requirement for normal work. When that is the case it is permissible to fuse circuits 25 percent above the normal current demand. Thus, if the normal current demand is 100 amperes, fuse to 125 amperes, and fuse other normal current flows in the same proportion as closely as stock fuse capacities will permit.
When a projector light source circuit fuse blows, a switch, as shown in Fig. 27, may be thrown over, cutting a new set of fuses into operation. This switch should be installed as a precautionary measure for each projection circuit.
Fusing Motor Generators
(83) While it is not required, it is good procedure to install fuses on both primary and secondary sides of motor generator sets. A good, safe rule is to fuse 20 per cent in excess of the maximum current requirements on both primary and secondary sides.
Extra Fuses
(84) All projection rooms should have a plentiful supply of fuses of all types and capacities. When the proper fuse is not immediately available it is possible to temporarily protect a circuit with one fuse, bridging the other contacts with copper.
(85 ) Wire fuses are always unreliable but copper is regarded best in an emergency. Table 7 shows the fusing point of small copper wires.