Six disconnect rule

Status
Not open for further replies.
P

pollobot

Member
Location
Boise, Idaho, USA
Butting heads with an engineer here. They have two buildings fed off of one utility transformer, each building has its own service and grounding. The service laterals are also seperate from each other. The main distribution panels have less than 6 breakers and no main. The engineer says this is a code violation because there are 4 breakers on building A and 5 breakers on building B. (5 +4) = 9 breakers, which exceeds the six disconnect rule. I told them it is six per service, not six per transformer, but he's not listening. They want us to pay to install main breakers! I need some firepower here guys..
 
pollobot said:
Butting heads with an engineer here.
Click to expand...
You should never do that. We are perfect, and never make mistakes! :cool: :lol:

Take a look at the opening line of 230.71(A). It says you can have up to six disconnects for each of the services allowed by 230.2 (which does not apply to your situation) or allowed by the exception to 230.40 (which also does not apply to your situation). In each case, the code is talking about a single building, and giving limits for serving that building. You have two separate buildings. You can completely turn off each building with no more than six "throws of the hand." In doing so, you don't have to care whether the other building has power or not. The NEC does not impose limits on the utility that would restrict how many buildings they can serve with a single transformer. The code does not say that you have to be able to completely unload a utility transformer with no more than six disconnects. You do not have to add a main disconnect on either of your buildings.

charlie b said:
We are perfect, and never make mistakes!
Click to expand...
  • What never?
  • No never!
  • What never?
  • Well, hardly ever!


 
pollobot said:
Butting heads with an engineer here. They have two buildings fed off of one utility transformer, each building has its own service and grounding. The service laterals are also seperate from each other. The main distribution panels have less than 6 breakers and no main. The engineer says this is a code violation because there are 4 breakers on building A and 5 breakers on building B. (5 +4) = 9 breakers, which exceeds the six disconnect rule. I told them it is six per service, not six per transformer, but he's not listening. They want us to pay to install main breakers! I need some firepower here guys..
Click to expand...

Ok, First of all is he a Utility Engineer or just a local engineer doing the drawings for the NEC covered portion of the installation?

Next, The Utility will size the XFMR and determine how many buildings can be supplied off of the individual XFMR, not the engineer who is designing the buildings based on the NEC.

Next, are these service conductors, underground or service laterals....makes a difference in the fact that Service Conductors, Underground are within the scope of the NEC and service laterals are not if under the exclusive control of the POCO.

Each building is a separate structure and are treated as such, the 6 disconnect rule applies to each service to that individual structure. Clearly in 230.71 it expresses that their shall be no more than six sets of disconnects per service group.

Ok...while I am not a fan of saying show images from the 2014 Handbook to an Engineer but in this case I will explain why it may benefit them....while the image I am going to tell you about is not EXACTLY like your situation...it most eyes it would be better in proving your point in terms of the six disconnect issue and the grouping component.

In the 2014 NEC Handbook look at page 125 (Exhibit 230.11) and notice that the image shows (4) buildings (firewalls between them make it no different that your example...just without firewalls and separated), In his theory this would be a code violation...but clearly it shows (6) disconnects at each location from a single transformer....If he reads this and still does not understand then well.......not sure what else we could tell you.
 
You may also want to explain that upstream of the service point, the NEC does not apply. In this scenario, the service point is most likely the line side of each utility meter. Two services, up to 6 disconnects per service.
 
As a utility, we often use a single large transformer to feed several services. Much cheaper and takes up less real estate. I don't understand his issue.
 
meternerd said:
As a utility, we often use a single large transformer to feed several services. Much cheaper and takes up less real estate. I don't understand his issue.
Click to expand...

charlieb can explain to you that engineers were not put on this earth to be understood, simply obeyed :D
 
Why is the power company inspecting your work? I would call the authority having jurisdiction and ask him to straighten it out with the engineer
 
What do the approved plans show? If the engineer submitted the plans for review and the plans show single service disconnecting means for each building, I think you are going to have a problem.
 
pollobot said:
Butting heads with an engineer here. They have two buildings fed off of one utility transformer, each building has its own service and grounding. The service laterals are also seperate from each other. The main distribution panels have less than 6 breakers and no main. The engineer says this is a code violation because there are 4 breakers on building A and 5 breakers on building B. (5 +4) = 9 breakers, which exceeds the six disconnect rule. I told them it is six per service, not six per transformer, but he's not listening. They want us to pay to install main breakers! I need some firepower here guys..
Click to expand...
pollo -
Where are the meters?

and, as asked,

Who is the engineer working for?

ice
 
RB1 said:
What do the approved plans show? If the engineer submitted the plans for review and the plans show single service disconnecting means for each building, I think you are going to have a problem.
Click to expand...

What did you bid to? Bare code minimum or a set of engineered plans?
 
Status
Not open for further replies.
Top