Friday, March 17, 2023
Hello CQD, Keep up the great work! Can you please clarify the difference between Service Equipment - Disconnecting means vs Service Equipment - Overcurrent Protection per Article 230. Does it imply that a Separate Disconnect Switch at service is required even though the Service Equipment has a main circuit breaker? thank you. Abhi P
Hi Abhi, thank you for the kind words and your question.
Service Equipment - Disconnecting Means: In general, each building or structure connected to an electrical service must be provided with a means to disconnect all ungrounded conductors from those service conductors. This is the function of the Service Disconnect, and covered in Part VI of Article 230.
Service Equipment – Overcurrent Protection: Each ungrounded service conductor shall be protected from overload. This is typically achieved by using an overcurrent device like a fuse or circuit breaker installed in series with each ungrounded service conductor to provide overload protection. Part VII of Article 230 provides the minimum requirements for Service Overcurrent Protection.
Even though the Service Disconnecting Means and Service Overcurrent Protection are in two separate Parts of Article 230 it is common to achieve compliance with both Parts, using the same device. For example, a Circuit Breaker that complies with the requirements in Part VI and Part VII of Article 230 could service as both the Service Disconnect and Service Overcurrent Protection. Hope this helps.