Electrician Talk - Professional Electrical Contractors Forum - NEC Code Forum http://www.electriciantalk.com All chapters including General, Wiring and Protection, Wiring Methods and Materials, Equipment for General Use, Special Occupancies, Special Equipment, Special Conditions, and Communication Systems. en Mon, 06 Sep 2010 04:57:04 GMT vBulletin 60 http://www.electriciantalk.com/images/misc/rss.jpg Electrician Talk - Professional Electrical Contractors Forum - NEC Code Forum http://www.electriciantalk.com <![CDATA[Single & Three Phase Motor Loads on Three Phase Circuit]]> http://www.electriciantalk.com/f5/single-three-phase-motor-loads-three-phase-circuit-16321/ Sat, 04 Sep 2010 23:04:17 GMT NEC Motor Article 430 does not address three phase and single phase motors on a three phase circuit/feeder. The single phase motor can cause some... NEC Motor Article 430 does not address three phase and single phase motors on a three phase circuit/feeder. The single phase motor can cause some voltage and current imbalances that can potentially damage the three phase motor.
Internet link:
http://www.engineeringtoolbox.com/el...nce-d_648.html
Indicates the following:
Voltage imbalance between phases should not exceed 1%
Voltage Imbalance % Derating Factor
0 1.00
0.5 1.00
1.5 0.97
2.0 0.95
2.5 0.93
3.0 0.89
3.5 0.85
4.0 0.82
4.5 0.78
5.0 0.76
Please, does anyone have more information about this topic? ]]> NEC Code Forum josefbartos http://www.electriciantalk.com/f5/single-three-phase-motor-loads-three-phase-circuit-16321/ Lightning Protection Certs. http://www.electriciantalk.com/f5/lightning-protection-certs-16301/ Fri, 03 Sep 2010 22:03:22 GMT Greeting all, i've run into a "AHJ" issue (Authority Having Jurisdiction) with regards to lightning protection systems, seems neither my masters license nor my contractors license suits the requirements for certification for installations of the before mentioned. I've gone through the 2008 NFPA 780 and cant seem to find info on obtaining certification. Would this be something along the lines of a "NICET" cert ? this is in regards to FED/MIL related work and has come up on a recent project. And having installed several of these systems in the past without issue, only requirement was documented testing and reports showing values to ground and material specs. I would appreciate any input on this requirement. Thank you, Doug Larsen (Larsen Electric) Guam USA ]]> NEC Code Forum zinsco1 http://www.electriciantalk.com/f5/lightning-protection-certs-16301/ All this talk about grounding...... http://www.electriciantalk.com/f5/all-talk-about-grounding-16279/ Fri, 03 Sep 2010 02:44:41 GMT .........Made me start thinking, isolated grounding. Is it me, or does this seem like the most misunderstood grounding system? I have seen it done... .........Made me start thinking,

isolated grounding. Is it me, or does this seem like the most misunderstood grounding system? I have seen it done wrong a THOUSAND times. Not to mention I think it's all smoke and mirrors just like "super neutrals".

Discuss. ]]> NEC Code Forum slickvic277 http://www.electriciantalk.com/f5/all-talk-about-grounding-16279/ electrical panel ground vs. neutral http://www.electriciantalk.com/f5/electrical-panel-ground-vs-neutral-16264/ Thu, 02 Sep 2010 18:47:01 GMT This is probably going to make some you roll over:rolleyes:, but I'm just starting out as a home inspector and am having difficulty understanding the ground/neutral connections. I see the neutral going to a neutral bar and the ground going to a ground bar, but the neutral and ground appear to be connected. If the ground also goes to an outside ground rod and the neutral goes back to the electrical company--THEN why doesn't the load simply go into the ground vs. going through the neutral? I've asked 5 people in construction and they have no clue either, just tell me that's the way it works. Does electrical potential has something to do with it?

I also saw a situation where it appeared the neutral and ground were grounded through a water pipe and no neutral was connected to outside power?:eek:

If this is not the right forum for this then show me the way out...:blink:

Thanks, I just don't know where to go to get the right info. ]]> NEC Code Forum bobster http://www.electriciantalk.com/f5/electrical-panel-ground-vs-neutral-16264/ Switches in a damp/wet environment http://www.electriciantalk.com/f5/switches-damp-wet-environment-16258/ Thu, 02 Sep 2010 13:14:32 GMT So I found out the hard way that they don't make WP switches. :whistling2: You all can laugh now. So if I have a outside location with a switch do I need a in use cover or just a WP cover? Code book is at work.. ]]> NEC Code Forum nitro71 http://www.electriciantalk.com/f5/switches-damp-wet-environment-16258/ solar disconnect http://www.electriciantalk.com/f5/solar-disconnect-16255/ Thu, 02 Sep 2010 12:58:09 GMT situation: typical dwelling service, SE cable drop into meter socket and SE cable to main CB panel in basement. Solar ac disco mounted next to meter... situation: typical dwelling service, SE cable drop into meter socket and SE cable to main CB panel in basement. Solar ac disco mounted next to meter socket with line side tap. Underground conduit to ground mounted solar array and inverters.
question: would an additional AC solar disconnect be required in the basement next to the main service disco? I'm having a difficult time understanding the NEC rules for grouping of disconnects. ]]> NEC Code Forum I Conduit http://www.electriciantalk.com/f5/solar-disconnect-16255/ 250.52(a)(1) Jade learning interpertation http://www.electriciantalk.com/f5/250-52-1-jade-learning-interpertation-16253/ Thu, 02 Sep 2010 10:36:25 GMT Got a JADE LEARNING (continuing ed class on grounding course #1030810) book in the mail today. This one is on grounding. I looked at 250.52(a)(1)... Got a JADE LEARNING (continuing ed class on grounding course #1030810)
book in the mail today. This one is on grounding. I looked at 250.52(a)(1)
and here is their interpertation of that article.......

Metal underground water pipe that is in contact with the earth for at least 10ft MUST BE USED AS A GROUNDING ELECTRODE. Copper,iron, or steel water pipe is a grounding electrode. Metal water pipe used for drinking water, sprinkler systems or industrial processes are CONSIDERED GROUNDING ELECTRODES. ]]> NEC Code Forum jwjrw http://www.electriciantalk.com/f5/250-52-1-jade-learning-interpertation-16253/ Class 1 Div 1 UL and CSA http://www.electriciantalk.com/f5/class-1-div-1-ul-csa-16232/ Wed, 01 Sep 2010 21:54:52 GMT Can someone tell me if there is an armored cable that is Class 1 Div 1 UL and CSA approved? Can someone tell me if there is an armored cable that is Class 1 Div 1 UL and CSA approved? ]]> NEC Code Forum Kwatson http://www.electriciantalk.com/f5/class-1-div-1-ul-csa-16232/ cord and plug disc. 430.109 (F) http://www.electriciantalk.com/f5/cord-plug-disc-430-109-f-16223/ Wed, 01 Sep 2010 18:58:47 GMT In 430.109(F) the receptacle can it be pendant hung or can a twist lock female cord cap take it place? Where do Thank you In 430.109(F) the receptacle can it be pendant hung or can a twist lock female cord cap take it place? Where do Thank you ]]> NEC Code Forum old dude http://www.electriciantalk.com/f5/cord-plug-disc-430-109-f-16223/ Electrical Permit http://www.electriciantalk.com/f5/electrical-permit-16221/ Wed, 01 Sep 2010 18:55:25 GMT Is it required to take out an electrical permit to install network wiring for example cat 5 cabling in a commercial building ? Is it required to take out an electrical permit to install network wiring for example cat 5 cabling in a commercial building ? ]]> NEC Code Forum mpscaglione http://www.electriciantalk.com/f5/electrical-permit-16221/ Switch legs current carrying conductors? http://www.electriciantalk.com/f5/switch-legs-current-carrying-conductors-16215/ Wed, 01 Sep 2010 13:16:20 GMT I've seen some posts on other forums about running multiple switch legs in a conduit with out having to worry about derating them or so I thought. Lets say 20 switch legs, 2 circuits. Is there an exception for this? I didn't really read those threads but was in a situation where I had multiple switch legs on one circuit and the thought crossed my mind whether I had to count each switch leg as a current carrying conductor. ]]> NEC Code Forum nitro71 http://www.electriciantalk.com/f5/switch-legs-current-carrying-conductors-16215/ 210.12 (B) AFCI protection/dwelling units http://www.electriciantalk.com/f5/210-12-b-afci-protection-dwelling-units-16197/ Tue, 31 Aug 2010 22:08:04 GMT For those who are on 2008, I'm wondering how much the change from 2005 changed your general methods of wiring from previous years?

... Besides having to buy more afci breakers.

A lot?
A little?
None at all? ]]> NEC Code Forum Rudeboy http://www.electriciantalk.com/f5/210-12-b-afci-protection-dwelling-units-16197/ Dual rated TC cable http://www.electriciantalk.com/f5/dual-rated-tc-cable-16177/ Tue, 31 Aug 2010 02:38:48 GMT The other day I saw an advertisement for tray cable that was rated TC-ER and some SO variant. Does this mean I could pull it into conduit or DB it...
The other day I saw an advertisement for tray cable that was rated TC-ER and some SO variant. Does this mean I could pull it into conduit or DB it and then slap a cord cap on each end. I probably would never do it but just wondering?


]]> NEC Code Forum Jlarson http://www.electriciantalk.com/f5/dual-rated-tc-cable-16177/ need help finding an article http://www.electriciantalk.com/f5/need-help-finding-article-16137/ Sun, 29 Aug 2010 19:08:38 GMT Besides 110.14(a), where in the code does it say you cannot double tap off the load side of a disconnect, OC device, etc. This is driving me nuts not... Besides 110.14(a), where in the code does it say you cannot double tap off the load side of a disconnect, OC device, etc. This is driving me nuts not finding it. ]]> NEC Code Forum BuzzKill http://www.electriciantalk.com/f5/need-help-finding-article-16137/ RNC strap http://www.electriciantalk.com/f5/rnc-strap-16132/ Sun, 29 Aug 2010 02:43:29 GMT I was heading out of the shop on Friday when I saw a re-inspect form from the AHJ; regarding rewiring this ancient house that a customer had... I was heading out of the shop on Friday when I saw a re-inspect form from the AHJ; regarding rewiring this ancient house that a customer had re-located.
We replaced the service, 200 amp disco on the outside of the house, ran 4/0 AL 40' in RNC across the basement rafters and stubbed up to the 200 amp subpanel, all in conduit.
Anyway, the one comment that pertained to me was where the AHJ listed RNC strap must be listed for the purpose.
I have not had a chance to speak to the AHJ, but the strap that I used for my 2" RNC is stamped 2" Rigid.
What am I missing here? He has never mentioned this before when I used steel straps on RNC.
Am I required to use those cheap PVC straps for RNC?
Thanks,
Rick ]]> NEC Code Forum subelect http://www.electriciantalk.com/f5/rnc-strap-16132/