ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

ECN Shout Chat
Top Posters(30 Days)
Admin 17
Recent Posts
Old decora style outlets
by Admin. 03/25/17 11:40 AM
ESA Arc flash course
by TheShockDoctors. 03/24/17 10:15 AM
fuse rejectors
by HotLine1. 03/24/17 07:53 AM
Another Forum Update
by Admin. 03/22/17 03:04 PM
Dining room plugs
by watersparkfalls. 03/21/17 10:31 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,439 Are you busy
166,153 Re: Forum
160,611 Need opinion
Who's Online Now
2 registered members (switches, HotLine1), 77 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#129422 - 03/04/05 12:31 PM Article 250.4 (B)(2)  
unsaint32  Offline
Member
Joined: Aug 2004
Posts: 15
eden prairie, MN, USA
A quote from 250.4 (B)UNGROUNDED SYSTEM (2) , "[equipment bonding] shall be connected together and to the supply system grounded equipment."

Does the "supply system grounded equipment" indicate that the supply system is system-grounded? Or does that just mean that the suuply system's equipment bonding is connected to earth? (because an ungrounded system's equipment bonding gets connected to earth, but not to the power source)


Tools for Electricians:

#129423 - 03/18/05 03:35 PM Re: Article 250.4 (B)(2)  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 822
Michigan
Means Equipment grounding(bonding) conductors well tie together to reference ground.An ungrounded system must be grounded the same as a grounded system even thought theres no reference from phase conductors to ground. Reason if one phase goes to ground(ground dector lights) nothing but an alarm or Ground dection light going out. BUT if one phase goes out then another the bonding conductors Must be able to carry fault.Why are theses systems used. Water treament plants, sewage plants areas where going dn at the ist fault is not a option. Gives the operator time when ist fault is noticed to schedule a shutdn and take care of the problem.Thats the way I see it. I;ve worked on several of theses systems as our power company well no longer supply a high leg delta but well supply an ungrounded or one leg grounded system.For better info see Electrical Grounding 6th edition (Ronald P.O;Riley page (90) or Soares grounding book



Member Spotlight
mersadrad
mersadrad
Montreal, Quebec, Canada
Posts: 28
Joined: March 2011
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.009s Queries: 14 (0.002s) Memory: 0.7417 MB (Peak: 0.8592 MB) Zlib enabled. Server Time: 2017-03-25 19:41:59 UTC