ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Baseboard Mounted Light Bulb Socket
by SPSchuman. 07/15/19 03:22 PM
Hunter Fan Recalls Brunswick 3 & 4 Light Fans
by Admin. 07/11/19 11:08 AM
Honeywell Recalls some Smoke Sensors
by Admin. 07/11/19 11:03 AM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 9 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Article 250.4 (B)(2) #129422
03/04/05 12:31 PM
03/04/05 12:31 PM
U
unsaint32  Offline OP
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:
Re: Article 250.4 (B)(2) #129423
03/18/05 03:35 PM
03/18/05 03:35 PM
Y
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 849
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


Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
Attic Rat
Attic Rat
Bergen Co.,N.J. USA
Posts: 524
Joined: December 2003
Show All Member Profiles 
Top Posters(30 Days)
Admin 5
Popular Topics(Views)
257,104 Are you busy
192,936 Re: Forum
182,593 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.013s Queries: 14 (0.003s) Memory: 0.9430 MB (Peak: 1.0619 MB) Zlib enabled. Server Time: 2019-07-19 08:47:06 UTC