ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
334.80 and fire caulk
by gfretwell. 06/21/18 11:35 AM
Calling all Non-US members!! (Non-US only)
by HotLine1. 06/13/18 01:50 PM
GE Lighting Recalls LED Tube Lamps
by Admin. 06/12/18 09:32 PM
Ketra Recalls Recessed Downlights
by Admin. 06/12/18 09:17 PM
diazed fuses
by Texas_Ranger. 06/11/18 07:31 AM
New in the Gallery:
Plug terminals
Housebilding DIY wiring
Who's Online Now
1 registered members (gfretwell), 14 guests, and 8 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
transformer primary protection #165991
07/09/07 05:19 PM
07/09/07 05:19 PM
W
windmiller  Offline OP
Junior Member
Joined: Dec 2006
Posts: 43
Alaska
Hi,
I have a 480 V switch gear we are going to feed a new maint building from. We are going underground about 50 feet from the MCC to the new building. We wont need a disco for the primary of the transformer but will for the secondary right?

Thanks


We all live under one King
2017 / 2014 NEC & Related Books and Study Guides
Re: transformer primary protection [Re: windmiller] #165994
07/09/07 06:19 PM
07/09/07 06:19 PM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
You will need a disconnect at the building to satisfy 225.31. Transformers do not require disconnects, but they do require over current protection per Article 450. The feeder OCPD will provide the required primary protection. Secondary protection for the transformer many not be required, but in most cases the secondary conductors require protection at or near the transformer per 240.21(C).
Don


Don(resqcapt19)

Featured:

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

 

Member Spotlight
Potseal
Potseal
Saskatchewan
Posts: 264
Joined: February 2013
Show All Member Profiles 
Top Posters(30 Days)
twh 5
Popular Topics(Views)
247,629 Are you busy
184,973 Re: Forum
174,214 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.018s Queries: 15 (0.004s) Memory: 0.9431 MB (Peak: 1.0607 MB) Zlib enabled. Server Time: 2018-06-21 16:06:54 UTC