NEC 230.71 Max Number of Disconnects

[John #007]

As a consultant, I've been asked to review electrical installations in several multi occupancy buildings for code compliance.
In many cases I've found that the main electric service panel in the residence (apartment or condominium) has many more breakers than the code maximum of 6. None of these panels have had a main breaker and none of the residents had a clue where their main breaker was located or how to operate it. In most cases the main breaker was located in locked meter room. I've reviewed the code from multiple perspectives, but I can find the exception that allows this. But, it appears to be common practice. What am I missing here?
Thanks,

 

[charlie b]

Welcome to the Forum. You?ll find many opportunities to learn from our membership. I know that I have.

What you are missing is really two things.

First, the code does not limit a ?Main Lug Only Panel? (i.e., no main breaker) to six breakers. The six breaker limit has to do with protecting the cable coming into the panel. If you go from a service transformer to a building?s main panel, without putting an overcurrent device at the secondary of the transformer, then you have to protect the secondary conductors, in some manner, at the first opportunity. One way is to have a main breaker at the first panel. You are allowed to have up to six breakers fulfill that role. However, if you have an upstream panel that feeds each unit with a separate breaker, then that breaker protects the cable going into the unit?s panel. Therefore, the six breaker limit does not apply. You can have up to 42 breakers on the unit panel, and still not have a main breaker on that panel.

The thing you are looking for is in Article 230.72(C). It says that each occupant in a multi-occupant building must have access to the means of disconnecting power to their space. However, there is an exception that allows what you are describing. If the room with the meters and individual unit disconnecting means is locked, but can be accessed 24/7/365 by a representative of the building management, then each tenant does not have to have a key to that room, nor does each tenant have to have a main breaker in their own panel.

 

[John #007]

Thank You for the clarification, But!

Thank You for the clarification, But!

It was my understanding that the original thought process for the maximum of six breakers was that under the original NFPA reasoning ?all of the power at the residence could be shut off with a simple sweep of the hand and that six breakers was an acceptable maximum.?
I understand the protective aspects of the branch feeder and panel protection, but in an emergency the power to the entire residence cannot be shut off without sweeping each and every circuit breaker.
I?ve read the exception, but it appears to be pushed to its limits when we say 24/7/365. The FPN in the code says ?electric service and maintenance are provide for AND under continuous supervision? of the building management. In most cases there is no onsite person, but rather one unit owner designated to be the ?resident manager?. It has been my reasoning that ?Continuous supervision? is more than having access to a locked room in an obscure location by an untrained person 24/7/365. I agree many homeowners wouldn?t know what to do with a main circuit breaker if they had one.

 

[jwjrw]

main breaker

main breaker

It is common pratice here in nc to have an electrical room where only qualified persons or building maintaince persons have access to it. However each dwelling has a main breaker in the panel to shut off power if need be. Maybe its an ahj issue but main lug panels are not used here.

 

[Dave_PE]

John, the meter room is generally cosidered the "service equipment" location and the panel inside the living unit is not service equipment, it's fed from a feeder, not a service lateral.

Article 230 applies to services.....so you can have a MLO metercenter with a maximum of 6 tenant circuit breakers, if you have more than 6 tenants or 6 tenants and a house panel, you will need a main at the metercenter.