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

ECN Shout Chat
Top Posters(30 Days)
Admin 16
Recent Posts
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
TRUE POWER
by jraef. 03/21/17 09:13 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,331 Are you busy
166,070 Re: Forum
160,532 Need opinion
Who's Online Now
0 registered members (), 88 guests, and 12 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: 822
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
richard
richard
L.I. New York
Posts: 94
Joined: August 2003
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: 0.014s Queries: 15 (0.003s) Memory: 0.7492 MB (Peak: 0.8752 MB) Zlib enabled. Server Time: 2017-03-24 17:50:07 UTC