Mike Dolt Enterprises
Mike Dolt Enterprises
User: xformer, Location: Dallas, Tx
Asked on: Monday, March 14, 2011 at 9:24 am EDT
Answered on: Tuesday, May 14, 2024 at 2:46 am EDT
Question: Is the addition of 200.4 in 2011 to stem the problem of using an over sized neutral conductor for two branch circuits of the same phase? I read that multi wire circuits are still permissible. Can someone clarify this for me please?
200.4Addition in 2011
Yes, the addition of 200.4 in 2011 was intended to address the problem of using oversized neutral conductors for two branch circuits of the same phase. The code rule now requires that the neutral conductor have an ampacity of at least 1/3 the sum of the branch-circuit ampacities. This rule was added to prevent the neutral conductor from becoming overloaded and overheating.
Multi-Wire Circuits
Multi-wire circuits are still permissible under the 2023 NEC. However, they are only allowed in specific applications, such as three-phase four-wire wye systems. In addition, the installation of multi-wire circuits must comply with the requirements of 210.4.
Clarification
In summary, the addition of 200.4 in 2011 was intended to address the issue of oversized neutral conductors in two-phase branch circuits. Multi-wire circuits are still permissible, but their installation must meet the requirements of 210.
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