Practical Electrical Wiring, Residential, Farm, and Industrial |
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Page 226
... lumens to provide 1 foot- candle . Fifteen foot - candles will require 144 X 15 , or 2,160 lumens . The approximate lumens produced by general - purpose bulbs today are Watts Lumens Watts Lumens 15 140 150 2,600 25 260 200 3,650 40 465 ...
... lumens to provide 1 foot- candle . Fifteen foot - candles will require 144 X 15 , or 2,160 lumens . The approximate lumens produced by general - purpose bulbs today are Watts Lumens Watts Lumens 15 140 150 2,600 25 260 200 3,650 40 465 ...
Page 239
... lumens per watt , but a 50 - hr . bulb of the same wattage produces about 27 lumens per watt , while a Photoflood bulb of the same approximate wattage but only 10 - hr . life produces roughly 34 lumens per watt . Voltage of Lamp Bulbs ...
... lumens per watt , but a 50 - hr . bulb of the same wattage produces about 27 lumens per watt , while a Photoflood bulb of the same approximate wattage but only 10 - hr . life produces roughly 34 lumens per watt . Voltage of Lamp Bulbs ...
Page 480
... Lumens Required . From the known factors it is fairly easy to calculate the lumens required for any particular lighting problem . The formula is foot - candles X square feet ยท Lumens = utilization factor X maintenance factor Assume that ...
... Lumens Required . From the known factors it is fairly easy to calculate the lumens required for any particular lighting problem . The formula is foot - candles X square feet ยท Lumens = utilization factor X maintenance factor Assume that ...
Contents
PART | 1 |
Underwriters and Codes | 3 |
Basic Principles and Measurements | 15 |
Copyright | |
33 other sections not shown
Common terms and phrases
2-wire circuits 3-phase 3-way switches alternating current amperage amperes appliances battery black wire branch circuit building bulb candle power carrying capacity ceiling Chap chapter circuit breaker circular mils Code in Sec Code requires Code Sec conductor conduit connected connector controlled cord covered demand factor diameter disconnecting means equipment example feeder fixture floor flow fluorescent fluorescent lamp foot-candles full-load current grounded wire heater horsepower illumination installed insulation knob and tube lamp light locations locknut lumens maximum meter minimum motor mounted National Electrical Code neutral wire opening operating ordinary outlet box overcurrent device overcurrent protection panelboard permitted pull raceway ranges receptacle outlets rubber rubber-covered wire separate service switch shown in Fig similar simple single-phase sizes small appliance socket solder switch box Table terminal transformer type shown Underwriters ungrounded usually voltage drop volts wall watt-hours wattage watts white wire wires run