?
Monday, April 18, 2016
Question:
I had an interesting question come up and had a very difficult time explaining the answer; can you help? The State of Indiana is using the 2008 Edition of the National Electrical Code. A customer wants to install eight services, in two junction boxes in two different locations with no firewall. What rule would need to be referenced in the NEC for clarification?
My Answer: The picture below is from the 2008 Edition of the National Electrical Code Handbook (this is the edition that is current in the State of Indiana with the Indiana amendments) and the following explanation is with the exhibits. The basic idea is that the customer is permitted to have up to six service disconnecting means at each location. If the customer were to use junction cabinets to feed our meters and not put the service disconnecting means at the meter but chose to put the service disconnecting means in each unit, he could have his service disconnecting means inside each unit with six service disconnecting means in each location.
Thanks, Charlie Eldridge, Consultant
A
Answer:
Hey Charlie it's good to hear from you and thanks for your question. I'm trying to visualize what is being asked and it seems like there will be 8 services for 8 different tenants but the units are not separated by firewalls so they don't met the definition of separate buildings based on the definition of building in Article 100. As you know a building or structure is only allowed to be supplied by one service as stated in 230.2 unless any of the provisions in 230.2(A) through (D) are met. Exhibit 230.8 in the NEC Handbook (which I believe is the same for 2008 as 2014) is for 230.2(B)(1). So if you meet the condition of not having available space for the service equipment to be located where it is accessible to all occupants, and get the written consent of the AHJ as special permission is defined in Article 100 that can be done. Multiple service conductors (one for each occupancy in your example) are allowed using one or more of the exceptions in 230.40. Up to six disconnecting means is permitted for each service as stated in 230.71 but it is also permitted to have more than six (for example one at each occupancy) if you meet the conditions in 230.40 exceptions. I hope this helps.