[RE-wrenches] Supply Side Tap Overcurrent Protection

[Steven Lawrence]

230.80

"Where the service disconnecting means consists of more than one switch or circuit breaker, as permitted by 230.71, the combined ratings of all the switches or circuit breakers used shall not be less than the rating required by 230.79"


Steven Lawrence


___________________________________
Message: 1
Date: Wed, 31 Mar 2010 10:24:17 -0700
From: "Hans Frederickson" <hans at fredelectric.com>
To: "'RE-wrenches'" <re-wrenches at lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Supply Side Tap Overcurrent Protection
Message-ID: <71328CBB96B745889F63E627C93E8A52 at frederickson.local>
Content-Type: text/plain;	charset="us-ascii"

Anything less than a 100A main is a no-go a for residential service:

NEC 230.79(C):
"For a one-family dwelling, the service disconnecting means shall have a
rating of not less than 100 amperes, 3-wire."

Also, I don't think any AHJ is going to accept a load calculation in lieu of
proper bus sizing in the service. What's to stop the owner from adding loads
later on? I agree with Eric... time for a service upgrade.


-Hans Frederickson
 

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Steven
Lawrence
Sent: Wednesday, March 31, 2010 9:54 AM
To: re-wrenches at lists.re-wrenches.org
Subject: Re: [RE-wrenches] Supply Side Tap Overcurrent Protection

Why can't you do a line side tap and downsize the main breaker?  Use a 60A
main disconnect for the line side tap, and use a 60A main breaker for the
service panel.  That's similar to what I did except I downsized the 200A
main to a 150A. This also allowed a manual interlock kit in the main service
panel that can be fed from the backup load panel.  

Steven Lawrence