T-minator
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Found some serious errors in this exam prep book.
Save your money on this one. Thankfully I just copied the CD from the library.
I am taking the WI Master Electrician Exam. Think I will buy Mike Holt's material. Any recommendations for good materials?
Save your money on this one. Thankfully I just copied the CD from the library.
I am taking the WI Master Electrician Exam. Think I will buy Mike Holt's material. Any recommendations for good materials?
Electrician's Exam Preparation Guide to the 2011 NEC By: Dale Brickner |
Published by: Craftsman Book Company ISBN: 978-1-57218-255-43 Chapter 3 questions: 60. A department store is illuminated with 215 fluorescent lighting fixtures and connected to a 120-volt supply. Each lighting unit draws 2.2 amperes. How many 20-amp branch circuits are necessary to feed these fixtures if each branch circuit must not exceed 80% of the branch circuit rating? A: 20 x .8 = 16 amps, 16/2.2=7.27 or 7 per circuit (7*2.2=15.4amp). ( 215fixtures*2.2=473amp ) but?? 215 fixtures / only 7 per circuit = 30.714 or 31 circuits (15.4*30=only 462amp ) 30 x 7 is only 210 fixtures. 5 fixtures still remain. You need 31 circuits. This book says 30 circuits!!!! 473amp / 16amp = 29.56 exact 16amp circuits they are looking for which is not possible 64. A warehouse requires 60 kw of general illumination using 150 watt incandescent lamps connected to a 120-volt source. How many 20-ampere branch circuits are required to feed the lamps if the circuits are to be kept at 80% of their maximum rating? A: 20 x .8 = 16amps. 16/1.25=12.8 (12 x 1.25= 15amp per circuit ) 60,000 / 150 = 400 lamps and only 12 per circuit. So, 400 / 12 = 33.3333333 or 34 circuits. The wrong answer they want is 60,000/120 = 500amp 500/16=31.25 or 32 circuits ( they are calc. as if exact 16amp circuits. Won't they be surprised when they buy a 32 space panel!!! Chapter 4 questions: 11. What is the smallest copper wire size allowed for service-entrance conductors? A: (the wrong answer they are looking for is 8 awg cu and 6 awg al 230.31(B) is the reference which is for service-lateral conductors not service entrance conductors! Wow) 12. The smallest grounded or neutral conductor for an electric service using 1100 kcmil copper conductor is: A: (the wrong answer they are looking for is 2/0 from Table 250.66 which is the grounding electrode conductor not the neutral WOW!!!) I stopped after this question. |