ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
dsk 13
Admin 8
Recent Posts
OD of Alum and Copper
by HotLine1. 08/23/17 07:30 PM
Grid problem??
by annemarie1. 08/21/17 01:10 PM
Bathroom electrical
by doc. 08/19/17 06:53 AM
electircal ageing test on IPC
by SIAME. 08/15/17 02:43 AM
electrical aging test on IPC
by gfretwell. 08/15/17 12:27 AM
New in the Gallery:
Gallery Test
Popular Topics(Views)
240,167 Are you busy
175,834 Re: Forum
167,969 Need opinion
Who's Online Now
0 registered members (), 47 guests, and 6 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#186569 - 05/19/09 03:23 PM 25 KVA Transformer grounding  
wewire2  Offline
Member
Joined: Nov 2002
Posts: 244
California
Would it be OK to run the grounding electrode conductor for a 25 KVA 3 phase 480-208Y/120V transformer to the existing service ground in the adjacent switchgear? The only accessible building steel is bolted together lattice trusses(not a reliable ground)and the water entrance piping is not in the vicinity? Driving a ground rod would be extremely risky due to existing unknown substructures.


2017 / 2014 NEC & Related Books and Study Guides

#186577 - 05/19/09 09:14 PM Re: 25 KVA Transformer grounding [Re: wewire2]  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 825
Michigan
I'd say read 250.30 A(7)
Exception # 2.
2005 N.E.C.


#186584 - 05/20/09 02:57 AM Re: 25 KVA Transformer grounding [Re: Yoopersup]  
wewire2  Offline
Member
Joined: Nov 2002
Posts: 244
California
Good advice,thank you. I skipped right over that exception in my quest for the answer. The transformer is fed from a subpanel that is fed from the switchgear. I guess the next step is to verify whether the subpanel is suitable for use as service equipment.
Now I'm wondering what criteria the manufacturer must abide by in having their product listed as suitable for use as service equipment.



Member Spotlight
TOOL_5150
TOOL_5150
Bay Area
Posts: 61
Joined: August 2007
Show All Member Profiles 
Featured:

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

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.014s Queries: 15 (0.003s) Memory: 0.7509 MB (Peak: 0.8766 MB) Zlib enabled. Server Time: 2017-08-24 10:47:56 UTC