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| Subject - Misinterpreted Code, Load Calcs and Misused Tables | |
| wavector |
One of the errors I have witnessed is unlicensed or inexperience electricians using the EGC table 250-95 instead of the GEC table 250-94, when sizing GECs. I have seen this many times, and it seems to be a common error amongst the unlicensed. [Article 250] Another error within these ranks is the ampacity table interpretation. The 90° C column for ampacity with reference to overcurrent protection and terminal temperatures is misused by the unlicensed. Since there are no 90° C terminals, the table should be used for derating of current carrying conductors in a conduit. [Article 310] http://www.mikeholt.com/cgi-bin/codeforum/ultimatebb.cgi?ubb=get_topic;f=11;t=004516;p= Voltage drop and load calculations. I have experienced contractors who have never taken a competency exam, but have another's license for their operations, and cannot do a simple residential or commercial load calculation. It seems they rely on the utility companies to do the work for them, rather than attempt the unknown because of their lacking the knowledge to successfully attempt the task of properly adding loads together. It's embarrassing. [Article 220] Fixture whips. "Can't we just use the whips provided to chain the fixtures together?" This is a contractor talking here. Not only does the code prohibit the use of fixtures (i.e. fluorescent troffers) as raceway (with exceptions), the conductor sizes that come with the fixtures (i.e. pre-whipped) are inadequate as branch circuit conductors [1996 NEC 402-11 uses not permitted]. Master/slave fixture types are available from the manufacturer, and some fixtures are suitable as raceways to carry branch circuit conductor. But, they must have a 90° C rating if within 3" of the ballast [1996 NEC 410-31] |
| kbsparky | quote: To clarify this discussion with others now taking place on the boards, those sections of the Code are from the 1999 and prior editions. The 2002 and later editions of the Code has old table 250-94 moved to 250.66 and old table 250-95 is now found at 250.122. 
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| wavector | quote: Yeah, the only code book I have is the 1996. Someone stole my 2002, and I can't afford another code book right now. |
| devo | the "someone stole my book" didn't work in high school and doesn't work here...in Mass we have to buy a new code book for our three year reveiw, stay in this weekend and use the money to buy a book...and as for Mike Holt, I've found numerous things wrong in his books and would recommend not reading is literature |
| binney | I can find several grammar and spelling mistakes in your post, does that mean we should ignore all future posts on your behalf. I’ve read several books by Mike Holt, Tom Henry, and many others. There are a lot of grey areas in the NEC, this doesn’t make every difference in opinion wrong, it’s just the way it is. Our State Inspector has notified us that he has found several mistakes, (so to speak) or difference in opinion, in the 2005 handbook, and recommends us not using it. I find all these reference books useful in coming to my opinion of the code. |
| Ryan_J | quote: Where can I find a list of the books that you have written? I would be quite excited to take a look at them. I do technical editing for Mike's books, and I can assure you that I will be watching your posts here very closely in an effort to learn from someone like yourself who is never wrong. |
| luckyshadow | WOW --- Seems somebody stepped in some doo-doo here ! tread lightlyand be prepared when going after the " Big Dogs" like Mike Holt ! I feel Mike is right on track with his programs . 
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| blackrd | I will reserve my responses so I dont get into trouble too. I think Mike has more experience than I do, so I will always defer to industry professionals rather than try to answer my own questions when I dont have the answers |
| Ryan_J | I hope nobody gets the wrong idea about my above post. I just think it takes a lot of guts to write something like that. I have read several books and I could point out discrepencies in all of them, but that is not to say that I am more knowledged than the author. I spent a week with Mike Holt down at his place in Florida a couple of months ago, and I can assure you that he is sharper than any one on this forum, including myself. |
| Alfred | Watch out ! Some Big Dogs do bark and some even bite. Thanks Alfred Johnson |
| sparky13 | I receive Mike's mail. I went to an ICC. class in Denver. Spent two days in his class, Five days there. I was more interested those two days then the rest of the week. Do not judge me by my grammer. |
| gftodd | I receive Mike Holt's mail too. I like his study aids, used them to pass Deleware & NJ state electrical exam's. Also liked the study aids for code changes. |
| sparky13 | I used his guides and quizes too. Passed my state contractor (master) test and inspector certifications. Highly recommended |
| kbsparky | quote: Tell me, how long ago did you take that Delaware exam? Are they still using the National Assessment Institute, with their 80 multiple choice questions? It's been over 14 years since I took the Delaware master test, and that was their procedure back in 1991. 
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| gftodd | I orginally passed Masters test 1993. Did not renew license,retested late 2004. Test was 100 questions open code book given by experior. Now that you mention it national assessment was also giving NJ state test back at that time, I wonder if experior was national assessment. |