dcsimg
Self Help Forums

Go Back   Self Help Forums > Building > Electrical Code - USA
Register FAQ Members List Calendar Today's Posts

Electrical Code - USA Commercial or Residential 1999 / 2002 / 2005 versions - for UNITED STATES

Reply
 
Thread Tools Display Modes
  #1   IP: 24.46.66.134
Old October 2nd, 2004, 09:41 AM
MIKEB MIKEB is offline
Junior Member
 
Join Date: Oct 2004
Posts: 2
Default 600 Amp Service

WHAT SIZE FEEDER DO YOU USE FOR A COMMERCIAL BULIDING WITH EXSISTING SERVICE RATED AT 600 AMPS .tHE NEVTRAL LOOKS LIKE #4/0 BUT THE FEEDER IS AN OLD RHW INSULATED CABLE .i CAN-T MAKE OUT THE SIZE OF WIRE ,THE WIRE NEEDS TO BE CHANGED DUE TO INSULATION CRACKING ...
Reply With Quote
  #2   IP: 165.121.27.198
Old October 2nd, 2004, 11:09 AM
Ohm1's Avatar
Ohm1 Ohm1 is offline
First Class Moderator

 
Join Date: Dec 2003
Location: WA
Posts: 4,631
Default posting

You may want to post this question in the commercial electrical forum.
__________________
Learning brings success. While you are waiting, I'm getting better!
Reply With Quote
  #3   IP: 68.193.88.245
Old October 2nd, 2004, 12:20 PM
Ron's Avatar
Ron Ron is offline
Senior Member
 
Join Date: Dec 2003
Location: New York
Posts: 293
Default

One possibility is Two sets of (4-350kCIMIL, #1 AWG Gnd) copper minimum
Check Table 310.16. If your doing this type of work, this kind of information should be at your fingertips.
__________________
Ron
Reply With Quote
  #4   IP: 24.46.66.134
Old October 5th, 2004, 05:03 AM
MIKEB MIKEB is offline
Junior Member
 
Join Date: Oct 2004
Posts: 2
Cool 600 Amp Service

I know T310-16 SHOWS AMPACITY . tHE PROBLEM IS THE EXSISTING WIRE IS IN A 4" CONDUIT CONTAING 3) RHW #______ AND ONE #4/0 . tHE 30 HOT LEGS WITHOUT INSULLATION LOOK LIKE A INSULATED 500KMCM WIRE .I'm not sur what size the wire is ,theirs no writting on it . According to the T310-16 it should be 1000kmcm . What do you think ???????
Reply With Quote
  #5   IP: 148.78.243.122
Old October 5th, 2004, 07:38 PM
Wgoodrich's Avatar
Wgoodrich Wgoodrich is offline
Super Moderator

 
Join Date: Sep 2002
Posts: 7,451
Default

Even though RHW is 90 degree rated 201.14 requires you to use the 75 degree column making minimum copper size for one conductor pulling 600 amps to be 1250 Kcml copper. There is not rating for aluminum that large of amp load in single wire. You would have to involve an engineer to size a single aluminum wire for that 600 amp load.

Be careful here in your decision. Remember the service conductor if this is what you are looking at is sized by the commercial demand load calculation rules of Chapter 2 of the NEC and not required to meet the main breaker size if the conductors are outside or nearest point of entry inside the building. If this is an MDP panel served from under the concrete floor this may be an engineered wiring design using the demand load calculation to size that conductor.

If this is PVC sch 80 conduit it is way too small for those conductors. Only one 1250 Kcml RHW wire is allowed in a 4" conduit. Same applies if this is rigid steel conduit.

Hope this helps

Wg
Reply With Quote
Reply






Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Service panel in bathroom (garage) *guest Electrical Code - USA 7 May 30th, 2009 09:10 AM
Neutral sizing Planeta Electrical Code - USA 3 December 11th, 2007 06:38 AM
Generator install at main service disconnect suemarkp Electrical - Existing Home 52 February 7th, 2006 09:37 AM
New Service *JOHNNY Electrical - Existing Home 0 December 12th, 2003 11:36 AM
400 amp wire and conduit size twigpig Electrical - Existing Home 1 May 26th, 2003 06:44 PM


All times are GMT -4. The time now is 06:22 PM.


Powered by vBulletin® Version 3.6.7
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
© 2002 - QuinStreet, Inc.
http://www.selfhelpforums.com