ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Potseal 11
Recent Posts
1913 American Electrician's Handbook
by annemarie1. 07/27/17 03:10 PM
600 KW 120/208 3 Phase Y protection
by Yooperup. 07/24/17 12:20 PM
Green House wiring
by ghost307. 07/20/17 09:10 AM
Permit Snafus...AHJs and Contractors Jump in
by HotLine1. 07/18/17 08:06 PM
New in the Gallery:
Housebilding DIY wiring
Popular Topics(Views)
239,367 Are you busy
174,822 Re: Forum
167,213 Need opinion
Who's Online Now
0 registered members (), 51 guests, and 6 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#101223 - 02/26/07 04:33 PM Feeder Taps  
Reel-Break  Offline
Member
Joined: Apr 2002
Posts: 178
nc
We`re working in a plant wiring a machine and they have in switch gear room a 600 amp breaker 3 500`s feed a JB from there a set of 3/0`s tapped to a 225 amp breaker and then another set of 3/0`s tapped to 200 amp. Is all well with this? I read the feeder tap rules but wasn`t sure about the loading of the main 600 amp is this considered cont load or non or does this effect calculations? Do you figure .80 which would be rughly 480 amps continuous? Thanks for some insight. These are textile machines many motors.


2017 / 2014 NEC & Related Books and Study Guides

#101224 - 02/26/07 05:18 PM Re: Feeder Taps  
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
The load calculations and the tap rules are two different issues. This installation appears to comply with 240.21(B) assuming the 3/0s are 25' or less. You would have to do a load calculation as to the total loads, however with only 425 amps of overcurrent protection on the taps, there is no way that the 600 amp circuit is overloaded.
don


Don(resqcapt19)


Member Spotlight
HCE727
HCE727
Delaware County, PA, USA
Posts: 186
Joined: November 2005
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: 0.009s Queries: 14 (0.002s) Memory: 0.7434 MB (Peak: 0.8630 MB) Zlib enabled. Server Time: 2017-07-28 00:47:30 UTC