Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 11-25-2012, 09:09 PM   #1
NJ DIY'er
 
Join Date: Nov 2012
Location: New Jersey
Posts: 2
Share |
Default

Subpanel vs Main feeds amp ratio limits? NEC 2005


I live in NJ in a town that follows NEC 2005 codes. I live in a ~1800square ft. house with 1 primary electric panel. Looking for planning help to prep for design and permit application.

I'm looking to install a new sub-panel (Square D QO 100A / 20 slots / with 100A main breaker) very close to the main panel and feeding it with a 100A breaker. Does feeding 100A to the sub-panel from a main panel that is only 100A cause any code violations?

I'm looking to move a 10-12 breakers off the main to the sub and then add in a breaker to feed in a generator using an interlock kit.

I've researched other items and plan on unbonding / keeping separate neutral from ground in the sub panel. Also using #3 THHN copper with #8 ground through PVC conduit between main and new sub-panel.

Any tips and help greatly appreciated!!

Minot is offline   Reply With Quote
Old 11-25-2012, 09:17 PM   #2
Licensed Electrician
 
k_buz's Avatar
 
Join Date: Mar 2012
Location: SE Wisconsin
Posts: 4,246
Default

Subpanel vs Main feeds amp ratio limits? NEC 2005


All a sub panel does is increase the available spaces to install breakers. If you have a full 100A panel, I suspect you will need to upgrade the service to 200A, and then install the sub panel if still needed.

To start, you could list all 240V appliances...Water Heater, Dryer, Furnace, AC, Range, Hot Tub....

__________________
__________________________________________________ ______________
Answers based on the National Electric Code. Always check local amendments.


k_buz is offline   Reply With Quote
Old 11-25-2012, 09:43 PM   #3
NJ DIY'er
 
Join Date: Nov 2012
Location: New Jersey
Posts: 2
Default

Subpanel vs Main feeds amp ratio limits? NEC 2005


The only 240v items are:

- Dryer
- AC

If I didn't upgrade to 200A and kept it at 100A, would I be violating any codes? I am hoping I don't need to upgrade my main to 200A.
Minot is offline   Reply With Quote
Old 11-25-2012, 09:50 PM   #4
Electrical Contractor
 
jbfan's Avatar
 
Join Date: Jun 2004
Location: Newnan GA
Posts: 5,479
Default

Subpanel vs Main feeds amp ratio limits? NEC 2005


You do not need a main breaker in the sub, unless you already have the panel.

A 60 amp feed should be more than enough.
__________________
Yes I am a Pirate, 200 years too late. "Jimmy Buffett"
jbfan is online now   Reply With Quote
Old 11-25-2012, 10:12 PM   #5
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Default

Subpanel vs Main feeds amp ratio limits? NEC 2005


You should be ok with the load as you posted there.

60 amp subpanel is plenty big for that useage.

Merci,
Marc
__________________
The answer will be based on NEC ( National Electrical code ) or CEC ( Cananda Electrical code ) or ECF ( Electrique Code France )
frenchelectrican is offline   Reply With Quote
Old 11-25-2012, 10:33 PM   #6
Member
 
JuzRick's Avatar
 
Join Date: Nov 2012
Location: SC
Posts: 132
Default

Subpanel vs Main feeds amp ratio limits? NEC 2005


Quote:
Originally Posted by k_buz View Post
all a sub panel does is increase the available spaces to install breakers. If you have a full 100a panel, i suspect you will need to upgrade the service to 200a, and then install the sub panel if still needed.

To start, you could list all 240v appliances...water heater, dryer, furnace, ac, range, hot tub....

i very well agree...
JuzRick is offline   Reply With Quote
Old 11-27-2012, 09:22 AM   #7
Lic Electrical Inspector
 
electures's Avatar
 
Join Date: Dec 2009
Location: The Great Police State of New Jersey
Posts: 1,513
Default

Subpanel vs Main feeds amp ratio limits? NEC 2005


Quote:
Originally Posted by Minot View Post
I live in NJ in a town that follows NEC 2005 codes. I live in a ~1800square ft. house with 1 primary electric panel. Looking for planning help to prep for design and permit application.

I'm looking to install a new sub-panel (Square D QO 100A / 20 slots / with 100A main breaker) very close to the main panel and feeding it with a 100A breaker. Does feeding 100A to the sub-panel from a main panel that is only 100A cause any code violations?

I'm looking to move a 10-12 breakers off the main to the sub and then add in a breaker to feed in a generator using an interlock kit.

I've researched other items and plan on unbonding / keeping separate neutral from ground in the sub panel. Also using #3 THHN copper with #8 ground through PVC conduit between main and new sub-panel.

Any tips and help greatly appreciated!!
No town in New Jersey is following the 2005 NEC. AS of 11/7/12 the 2011 NEC has been adopted with ammendments. Follow the links in my signature for DIY in New Jersey.

__________________
All responses based on the 2011 NEC.
If you live in New Jersey click
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
. All other states click
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.
Please check with local, county and state officials as laws may vary.
Sizing motors
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
. Online motor calculator
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
. Online calculators
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
.
electures is offline   Reply With Quote
Reply

Tags
100a, generator, interlock, square d, subpanel


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Subpanel Right Below Main dcapone Electrical 6 01-02-2012 04:46 PM
Connecting subpanel to main panel rtyui2 Electrical 10 12-07-2007 06:29 PM
combining subpanel with main johnny331 Electrical 1 06-06-2007 06:27 PM
Splice box/s between subpanel and main panel? SeanR Electrical 5 05-06-2007 02:21 PM
Add subpanel or upgrade main panel dcoz Electrical 1 01-12-2006 09:24 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.