ANSWERS: 3
• If you assume the V and the A are in phase, the answer would be: (3 * 40A * 480V / 1000) * 0.055 by the way, I assume you mean 5.5 cents per kWh.
• Answer is edited P=(under root of 3)*V*i*cos(phie) (under root of 3 can be taken as 1.73 V=voltage, i= current, P= power in Watt cos phie=power factor of your area ,which can be taken as 1,otherwise in my part of world it is taken as 0.85, butb we shall take it as 1 for the subject question(for enginnering calculation it is considered ,otherwise ,formula can be written with out power factor also) P=1.73*480*40*1=33216 watthour/1000=33.3216Kwh You consumed this power for 1 hour, rate of power@\$5.5 per hour the cost of power =5.5*33.216=\$182.688 If that is the cost of power in your part of world for one hour then why don`t you immigrate to my country ;) Edited portion:If your motor consumed the 40HP power as per the ratings stated on the motor rating plate then 1HP=745Watt so 40HP=745*40=29800Watt=29.8Kwatt power@ \$5.5 per KWh=5.5*29.8=\$163.9 (In my personal view \$182.688 is correct.)
• Hai Mike! you brought down the amps from 40 to 32. Same question but with 32 amps instead of 40. In my earlier detailed answer put the value of current as 32 in place of 40.The answer must be \$146.15

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