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Re: The most screwed up electrical work I have ever seen.What? Creative at best Wayne. We had such a problem with adverse environmental conditions, rust, corrosion etc that the physical electrical integrity of the threaded connections could not be guaranteed. Thus all our circuits and motor feeders had to have a ground wire pulled in. We even had PVC inserted in some places in a regular rigid galvanized conduit run and Stainless Steel conduit. Neither a good conductor. Agree?
BTW you said that was the "Most screwed up electrical work you have ever seen" That is good compared to some I've seen. |
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49528867 (banned) join:2010-04-16 Fort Lauderdale, FL 2 edits |
49528867 (banned)
Member
2012-Aug-28 7:10 pm
Plumbers dope aside... Jack what I posted is based on the NEC not creativity... Ever heard of concentric knockouts? Based on my already posted comments, any idea of the code requirements if one was to run a metallic conduit from a meter can to a breaker panel if either of those metallic cans have concentric knockouts??? And if you do, then why do you think the code requires a grounding bushing on that metallic conduit when it is already being connected to two well grounded metallic cabinets??? Himmm. We had such a problem with adverse environmental conditions, rust, corrosion etc that the physical electrical integrity of the threaded connections could not be guaranteed. Thus all our circuits and motor feeders had to have a ground wire pulled in. We even had PVC inserted in some places in a regular rigid galvanized conduit run and Stainless Steel conduit. Neither a good conductor. Agree What I would agree with is where you worked should have been shut down and those in charge of maintenance prosecuted for the numerous violations and hazardous conditions you just mentioned. There is NO excuse for allowing such crap to exist. Time to put the shovel away guy as the hole you are in is deep enough
Wayne |
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Can't resist an attack when someone questions you can you? Your little sanitized world is evidently no where close to the real world with real world conditions and requirements. Not a simple meter pan hookup. What's with the concentric knockouts? It was an industrial facility and fully complied with and met all applicable requirements. You would not last a week in that plant. |
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49528867 (banned) join:2010-04-16 Fort Lauderdale, FL |
49528867 (banned)
Member
2012-Aug-28 7:30 pm
said by Jack_in_VA:Not a simple meter pan hookup. It was an industrial facility and fully complied with and met all applicable requirements. Based on what you already posted about where you worked that seems not possible... To me what you described sounds like a plant that belongs in a third world county where the cost of an incident is weighed low against corporate profit. Kinda like the Dow Chemical incident in Bhopal
Wayne |
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49528867 (banned) join:2010-04-16 Fort Lauderdale, FL 1 edit |
to Jack_in_VA
250.100 Bonding in Hazardous (Classified) Locations. Regardless of the voltage of the electrical system, the electrical continuity of noncurrent-carrying metal parts of equipment, raceways, and other enclosures in any hazardous (classified) location as defined in Article 500 shall be ensured by any of the methods specified in 250.92(B)(2) through (B)(4) that are approved for the wiring method used. One or more of these bonding methods shall be used whether or not supplementary equipment grounding conductors are installed. Note the use of the term shall because in the code shall means something important. 250.92 Services. (B) Method of Bonding at the Service. Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be ensured by one of the following methods: (1) Bonding equipment to the grounded service conductor in a manner provided in 250.8 (2) Connections utilizing threaded couplings or threaded bosses on enclosures where made up wrenchtight (3) Threadless couplings and connectors where made up tight for metal raceways and metal-clad cables (4) Other listed devices, such as bonding-type locknuts, bushings, or bushings with bonding jumpers Wayne |
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49528867 |
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said by Jack_in_VA:What's with the concentric knockouts? It was an example of how important a good path to ground is and the fact that even though a concentric knockout provides a metallic connection it is insufficient to be trusted to handle fault currents. Now if a concentric knockout is insufficient, doped up threads are truly insufficient. 250.92 Services. Bonding jumpers meeting the other requirements of this article shall be used around concentric or eccentric knockouts that are punched or otherwise formed so as to impair the electrical connection to ground. Standard locknuts or bushings shall not be the sole means for the bonding required by this section. Wayne |
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Nick_L Premium Member join:2003-01-22 Pittsburgh, PA |
Nick_L
Premium Member
2012-Sep-6 2:42 am
Since we're doing Q&A, if you don't mind, would you explain eccentric knockout? Concentric I understand.
Thx |
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49528867 (banned) join:2010-04-16 Fort Lauderdale, FL |
49528867 (banned)
Member
2012-Sep-6 11:11 am
said by Nick_L:Since we're doing Q&A, if you don't mind, would you explain eccentric knockout? Concentric I understand.
Thx Whereas a concentric knockout has a blank plug surrounded by larger and larger rings an eccentric knockout has the blank plug against the edge of cabinet surrounded by larger and larger knockouts that resemble the letter C. While I am out today I will see if I can find one and post a shot of it. Wayne |
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Nick_L Premium Member join:2003-01-22 Pittsburgh, PA |
Nick_L
Premium Member
2012-Sep-6 5:48 pm
Thanks for the education. I've not seen those (that I'm aware of, anyway). |
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49528867 (banned) join:2010-04-16 Fort Lauderdale, FL |
49528867 (banned)
Member
2012-Sep-6 6:13 pm
said by Nick_L:Thanks for the education. I've not seen those (that I'm aware of, anyway). I didn't have a chance to locate one today but this is a catalog shot of some.
Wayne
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Nick_L Premium Member join:2003-01-22 Pittsburgh, PA |
Nick_L
Premium Member
2012-Sep-9 3:50 pm
Thanks. |
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