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alternating current amount ampere-hours ampere-turns amperes arc lamps armature core armature current belt brushes candle-power carbon cause cell cent characteristic curve charged circuit breaker commutator conductors connected constant constant-potential copper counter E. M. F. cut-out decrease direct current direct-current discharge dynamo efficiency electrical electrolyte energy engine external circuit feet field coils field magnets field strength field winding friction full load fuses ground heat Hence hysteresis illumination incandescent lamps inch increase induction insulation iron light lines of force loss machine magnetic circuit magnetizing force mechanical metal method necessary negative ohms parallel placed plates pole pieces position potential pulley regulation Remedy resistance reversed revolutions per minute rheostat ring rotation series coils shaft short circuit shown in Fig shows shunt motor soldered sparking speed storage battery surface switch Symptom terminals tion torque usually varies voltage voltmeter volts wattmeter watts wire
Сторінка 331 - Cut-outs or circuit breakers should be placed at every point where a change is made in the size of wire, unless such a device in the larger wire will protect the smaller.
Сторінка 317 - Must be so placed in wet places that an air space will be left between conductors and pipes in crossing, and the former must be run in such a way that they cannot come in contact with the pipe accidentally. Wires should be run over, rather than under, pipes upon which moisture is likely to gather or which, by leaking, might cause trouble on a circuit.
Сторінка 327 - No combination fixture in which the conductors are concealed in a space less than one-fourth inch between the inside pipe and the outside casing, will be approved. h. Each fixture must be tested for "contacts...
Сторінка 5 - It has been found that the best results are obtained when the tension in the driving side of the rope is only 3 to 4 per cent of the breaking strength. The diameter of a single rope necessary to transmit a required HP is given by the formula: 825 HP V(200 — ^ 1,072/ in which HP == horse-power transmitted; V = velocity of rope in feet per second; D = diameter of rope in inches.
Сторінка 331 - ... the wires ; that is, in a two-wire system the two wires, and in a three-wire system the three wires, must be protected by the cut-out and disconnected by the operation of the switch or circuit breaker.
Сторінка 346 - ... in accordance with the rules and requirements of the National Board of Fire Underwriters. Section 5. — That all exits shall be plainly indicated by a sign, same to be illuminated by either gas, or animal oil, and bear the word "EXIT," the letters of which must not be less than four (4) inches in height.
Сторінка 328 - ... submersion in water at 70 degrees Fahrenheit. The outer protecting braiding should be so put on and sealed in place that when cut it will not fray out. Flexible cord should not be used as a support for clusters, as it is not strong enough, and it should never be used for anything other than pendants, wiring of fixtures and portable lamps, portable motors, or small, light electrical apparatus. Flexible...
Сторінка 339 - With naked open fuses, of ordinary shapes and not over 500 amperes capacity, the maximum current which will melt them in about five minutes may be safely taken as the melting point, as the fuse practically reaches its maximum temperature in this time. With larger fuses a longer time is necessary.
Сторінка 34 - S can be turned as shown until all the resistance-coils c/, «, c/, are cut out, and the motor is directly connected to the circuit and running at full speed. The arm S should be turned slowly enough to allow the speed and counter EMF to come up as the resistances a, a, a are cut out. The arm S should positively close the field circuit first, so that the magnetism reaches its full strength (which may take several seconds) before the armature is connected. In the arrangement shown in Fig.