ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
UL 508A SPACING
by ale348 - 03/29/24 01:09 AM
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (ale348), 302 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Nov 2004
Posts: 138
C
Member
Ok...in a residential 200A service, if you add up the breakers you can have well over 200A. I realize that not all the loads are on at the same time which is why the main doesn't trip...but how does one really KNOW if the service can handle all the ciriuts..and is this information found in the NEC??

Also...as far as subpanels go....what's stopping me from putting a 100A sub at the end of the house opposite the main panel? and then adding another 100A sub in the garage for a welder and other shop machines?

Are these found in the code too?

Joined: Apr 2002
Posts: 7,381
Likes: 7
Member
Clyde:
Math 40 circuit panel....20 amp, 1 pole cb's
800 amps; divide by 2 hot legs (resi)= 400 amp max connected load. BUT, the 200 amp main would trip.

Load calcs are in the NEC

Theory is you can have an unlimited quantity of "sub-panels", the limitations are the OCP of the main, and the OCP of the feeders.

John


John
Joined: Feb 2003
Posts: 687
A
Member
Overcurrent protection is not the load. Also figure in the demand factor. I tend to be suprised how little draw I find on a panel for a big place on a normal day.

Besides reading the NEC you might try books explaining the NEC. I like Illistrated ones because a picture is worth a lot of big words for me.

Tom

Joined: Jun 2005
Posts: 821
S
Member
Article 220 would seem helpful in this situtation.

Joined: Nov 2004
Posts: 138
C
Member
thanks...will definately check out 220


Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5