Mark P Posted March 8, 2007 Report Share Posted March 8, 2007 A 200 amp main breaker with 2 copper #4 AWG connected. Home built in 50's. Now I know #4 is rated for 100amp, but I can't believe 2 #4 would equal 200 amp. Electrical is not my strong suit, but this just seems silly. Am I missing something? I'm recommending a sparky evaluate, but wanted some education and oppinions for the TIJ community. Thanks Mark Download Attachment: 1.jpg 77.9 KB Quote Link to comment Share on other sites More sharing options...
hausdok Posted March 8, 2007 Report Share Posted March 8, 2007 Looks like a 30-40 year old panel. Yep, sparky was definitely trippin'. Must have been out in the car tokin' and listening to Cheech & Chong records during the lunch break. Good call! OT - OF!!! M. Quote Link to comment Share on other sites More sharing options...
PAbernathy Posted March 8, 2007 Report Share Posted March 8, 2007 Good evaluation my friend........ 310.4 Conductors in Parallel. Aluminum, copper-clad aluminum, or copper conductors of size 1/0 AWG and larger, comprising each phase, neutral, or grounded circuit conductor, shall be permitted to be connected in parallel (electrically joined at both ends to form a single conductor). The Cross Section of (2) # 4 AWG has a Circular Mill of 41740 and do that times 2 would give you only 83,480 circular mills....so basically equal to a # 1 CU at best...lets assume all copper here as it makes it easier..... So even IF it was allowed ( which it is not via Article 310 ) it would under 310.15(b)(6) only be good for 150A....not 200A.....since a 2/0 CU has a 133,100 circular mill....so to answer your question....your GUT feeling was right and WELL DONE.....WELL DONE my friend. So in the end.....the parallel conductor is wrong....they are not larger than 1/0 and the conductors themselves are not " EVEN COMBINED" enough for the 200A service. ie: Circular Mills is the technical size of the conductor for clarrification. Sorry for being so technical....honestly I tried to break it down.... Electricians use this to size many things using the actual circular mils of the conductor...and I just used it to show why (2) # 4 AWG conductors are not the same as a 2/0 AWG CU conductor..... Quote Link to comment Share on other sites More sharing options...
Mark P Posted March 8, 2007 Author Report Share Posted March 8, 2007 Wow Paul, now that's a lot of education! I only had to read it 8 times to follow what your saying, but I sure do appreciate you taking the time to say it. Quote Link to comment Share on other sites More sharing options...
PAbernathy Posted March 8, 2007 Report Share Posted March 8, 2007 lol...sorry as their is other way to say it. When I post something I like to back up WHY it is and basically for a lack of better term......even (2) # 4's together ( If allowed ) would not handle the 200A panel.....sorry sometimes I over educate but their is a method to the madness. Quote Link to comment Share on other sites More sharing options...
kurt Posted March 8, 2007 Report Share Posted March 8, 2007 That's very helpful, useful information. Thanx. Quote Link to comment Share on other sites More sharing options...
Mark P Posted September 19, 2008 Author Report Share Posted September 19, 2008 I know this is an old post, but I found another one. This time it is two #3 hooked to a 200amp main disconnect. The house already passed city inspection, which really annoyed me and my client especially since he works for the city, but not as an inspector. Image Insert: 72.59 KB Quote Link to comment Share on other sites More sharing options...
msteger Posted September 19, 2008 Report Share Posted September 19, 2008 We have no way of knowing if the terminals on the main breaker lugs were torqued to the amount required when the extra lines were added. Whenever I see main lugs double tapped, I call it out for further review by a licensed electrician. Quote Link to comment Share on other sites More sharing options...
Jim Katen Posted September 20, 2008 Report Share Posted September 20, 2008 Originally posted by AHIS I know this is an old post, but I found another one. This time it is two #3 hooked to a 200amp main disconnect. The house already passed city inspection, which really annoyed me and my client especially since he works for the city, but not as an inspector. As Paul pointed out earlier in this thread, it's not allowed. You can only install parallel conductors with 1/0 or larger wire. There's an exception that allows paralleling neutral wires down to #2 under engineered supervision. There's no provision for paralleling #3. Even if the parallel conductors were allowed, you'd need lugs that were rated for more than one conductor. - Jim Katen, Oregon Quote Link to comment Share on other sites More sharing options...
Mark P Posted September 20, 2008 Author Report Share Posted September 20, 2008 Thanks Jim, but I understand it is not allowed. I posted the second pic because I find it interesting and just wanted to share it. Also interesting is that both setups were in the same town and both passed city inspection because the city guys never remove the covers. They just walk around with a 3 prong tester and test for GFCI and peeling paint then hand you a bill for $100. Then the realtors use it as a selling point "Passed City Inspection". Quote Link to comment Share on other sites More sharing options...
Speedy Petey Posted September 21, 2008 Report Share Posted September 21, 2008 Originally posted by msteger We have no way of knowing if the terminals on the main breaker lugs were torqued to the amount required when the extra lines were added. Doesn't matter. See post #9. Quote Link to comment Share on other sites More sharing options...
PAbernathy Posted October 5, 2008 Report Share Posted October 5, 2008 Not to mention I am sure those lugs shown are not rated for more than a single conductor anyway so it would be yet another problem. Quote Link to comment Share on other sites More sharing options...
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