thanks for the clarification.
2020- 230.71(B) & 225.30(B) - Effect on homes with 2 - 200 amp panels
- Thread starter sw_ross
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
If the meter main does not have a 400 amp breaker then you will not be allowed to use it in the 2020. I always use the 400 amp base (320) and 2 wp panels. This will remain compliant as long as they have a main. The mains also must be outside now for one an 2 family dwellings
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Thinking of how i would do this considering all these rules: If the meter was to be on the house, and assuming a meter/main didnt meet the "separate compartment" requirement, I would likely go to 2 200A circuit breaker enclosures, then in to two main lug panels.
If the meter was remote on a pedestal, I would keep them SEC and run two sets to each 200A breaker enclosure as above.
Alternatively one could get a 400 A exterior breaker and use a 400A panelboard inside or use the tap rules to hit 2-200's, but I assume the previous options would be more affordable.
If the meter was remote on a pedestal, I would keep them SEC and run two sets to each 200A breaker enclosure as above.
Alternatively one could get a 400 A exterior breaker and use a 400A panelboard inside or use the tap rules to hit 2-200's, but I assume the previous options would be more affordable.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Hmmm... interesting. Reading 225.30 it seems to me a lot of services I have seen may have been in violation of your second point - one 320A meter feeds two separate 200A disconnecting means with OCP, which in turn feed two separate panels on the same building. I assume it was done this way because 400A switchgear is more than twice the cost of 200A equipment.
Could it possibly mean that a building can only be supplied by one feeder from a given service disconnecting means, and if there are two discos there can be two feeders? That seems like a bit of a reach from the letter of the code, which says ,"...feeder on the load side of a service disconnecting means..." (emphasis mine, and it's from the 2011 NEC, the only one I have handy).
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Yeah seems like a reach to me too, but I see what you mean by the "a". Also, its odd they even put "service disconnecting means" in there - cant think of how one could have a feeder that is NOT on the "load side of a disconnecting means." The wording there could definitely use a little love
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I hope we are still talking about the 2020 NEC
Article 225 is about outside branch circuits and feeders not services and the way I read it I can have 6 feeder to a structure if the all come from the same panelboard etc. This section quoted (225.30) is a new section
It has never been a violation, nor is it in the 2020 to have a 320 meter base with 2 main disconnect panels outside that feed 2- mail lug panels indoor.s
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Ok Dennis thanks for that section. Ok so they have new wording that allows it in 2020, but I see no such language in 2014 so I am not following how you justify saying "it has never been a violation." Can you clarify?
- Location
- Illinois
- Occupation
- retired electrician
I agree, assuming the disconnects are physically mounted on the building. If the disconnects are remote, I would disagree. Where the disconnects are mounted on the building it is no different than a large commercial building with multiple feeders to panels scattered around the building.
Not attempting to pirate MH’s info on the subject,
Looking at the 2020 code and his book and video on the topic again this morning;
it looks like I would be ok to install a 320 meter/main (Siemens product I mentioned) that has 2 - 200 amp breakers and run 2 feeders to the structure as long as they end up terminating in separate discos that are located outside the structure and are grouped? The clincher is that the feeders have to originate from the same panel board! (If I’m understanding things correctly!)
Looking at the 2020 code and his book and video on the topic again this morning;
it looks like I would be ok to install a 320 meter/main (Siemens product I mentioned) that has 2 - 200 amp breakers and run 2 feeders to the structure as long as they end up terminating in separate discos that are located outside the structure and are grouped? The clincher is that the feeders have to originate from the same panel board! (If I’m understanding things correctly!)
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kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Never was compliant.
First you can't have MLO panel as the first thing you hit at the house, must have 1-6 mains in or on the house, short distance away may be accepted by some but is not in the NEC wording.
Second if your main(s) are away from the house then the house is supplied by a feeder(s). 225 part II is the applicable code here and 225.30 only permits one feeder to supply a separate building prior to 2020. 2020 it has moved (B) content and replaced it with wording that does allow multiple feeders if they all originate from same panel, switchboard, other gear, but you would still need a main at the house on each of those feeders.
My statement here was referencing a service that is located remote from the structure with feeders going to the structure, not ON the structure.
I live in a rural area where sometimes the service is not located at the structure , but might be located at the power pole where the poco xfrmr is located, then feeder(s) go to the structure.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
With new content in 230.71(B) the meter with two mains would need to have the two mains in separate compartments of the assembly to comply with this section. None of the ones I have ever seen in the past will comply, guessing manufacturers will be changing design but may or may not have product available soon enough for some and you will probably be using two separate main breaker enclosures when on the building supplied. In a situation like you are describing where it is away from the building supplied, you are out of luck until they make an assembly with separate compartments because you must run them multiple feeders from the same panel, switchboard, etc.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Here if the POCO is providing?maintaining that disconnect at the pole they don't consider it to be the service disconnecting means. POCO can and at times will change that disconnect to whatever is convenient or common for them to use at the time, it may be fused, circuit breaker or non fused equipment it gets replaced with then that changes what may or may not be extended from it code wise. So AHJ here has deemed it is just a point on the system that is convenient to the POCO for interconnection to customer wiring and convenient disconnecting means to isolate customer from utility without calling technicians out to disconnect the supply. We don't need to run an EGC from this point and all conductors leaving this point are still considered to be service conductors.
If your AHJ calls it the service disconnect then it is what it is and you need to apply things as worded in code.
Agreed. In our rural areas it is common to have it set up this way. That meter location, the site isolating point, is not the service. It's only a distribution point where service conductors can then run to the various buildings on the property (barn, shop, house, etc). Then the service is established at that location.
I have one poco here that doesn't do it that way and wants their service conductors to terminate in a meter asap within the property line. That's where I had been using the 320 Siemens meter/main. One feeder, 200 amp, went to the house, one went to the shop, etc.
Regarding 225.30(B), it talks about the 2-6 feeders originating from the same panelboard...
You're saying 230.71(B) requires those service disconnects to be in separate enclosures... I see that also.
I guess I'm confused about how to set up a 320 service for a house that needs 2 - 200 amps panel...?
Scenario #1 - meter located on the structure
Scenario #2 - meter located remote from the structure
The picture I posted earlier from MH's book adds to my confusion. It shows an example of a violation but doesn't show a code compliant way to do this set up.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
What Mike posted was a 400 amp service on a building with 2- 400 amp feeders each going to their own panel. That is what isn't compliant. They have to originate from the same panel
When a meter is mounted on a building and there are 2- main breaker panels as the service disconnect then that is compliant. You cannot have one panel, without a main, and use the 6 disconnect rule. The 6 disconnect rule now requires a separate panel for each panel.
It used to be we could use a 12 crcuit panel that was main lug only and install 6 dp breakers in that panel. This was compliant but no longer is compliant. The reason is that we need to be able to kill the bussbar in the panel.
When a meter is mounted on a building and there are 2- main breaker panels as the service disconnect then that is compliant. You cannot have one panel, without a main, and use the 6 disconnect rule. The 6 disconnect rule now requires a separate panel for each panel.
It used to be we could use a 12 crcuit panel that was main lug only and install 6 dp breakers in that panel. This was compliant but no longer is compliant. The reason is that we need to be able to kill the bussbar in the panel.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
A 400 amp service with 2 - 200 amp service panels where each panel feeds 2-2 panels, as Mike showed is not allowed. Not sure why the feeders need to originate in the same panel.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Washington has a exception to NEC that allows multiple feeders to a building, was six , was was increased recently. Reason was a 400 amp Class 320 service at head of driveway would require 400 amp feeder. We allow multiple smaller feeders as 200A is much less than single 400 amp. Feeder disconnects must be grouped on bldg.
Sorry but no! The AHJ can call anything they want service equipment but if is on the utility side of the demarcation point only the name in the National Electrical Safety Code (NESC) has any legal effect on what it is for code enforcement purposes. Do keep in mind that the enforcement of the NESC is the exclusive province of the State's utility regulating agency. I have never encountered any electric utility that will allow me to touch anything that they install or maintain.
Side observation: What I have seen in many places is a utility owned pole at the property line or in an easement that supports the utility end of what is technically a service drop; in spite of it looking exactly the same as the rest of the POCO lateral: which extends to, what many rural utilities call, a yard pole. Yard poles are customer owned even though they MAY look like all of the rest of the poles on that line. I have also seen utility owned rod operated pole-top switches on the last POCO owned pole. At the bottom of the Yard Pole there was often a Current Transformer (CT) type meter. From the top of the yard pole the individual drops extended to service equipment which was mounted on or in each building. The other arrangement which is becoming more common is for an underground Service Lateral from the last utility owned pole to come up to a Meter Mains assembly or to metered conductors in a trough supplying multiple disconnects. The feeders from those 1 to 6; but usually one more than there are buildings; then go underground, or even overhead via a Yard Pole, to the Building Disconnecting Means at the individual structures. The additional Service Disconnecting Means, over the number of structures served by the other feeders, is the one that supplies the water pump that is also used for "First Aid Firefighting."
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Tom Horne
Isn't there a kind of "gotcha" there in that, since neither of those separate feeders is the entire supply to the building, you cannot use the wire sizes called out in the residential service conductor sizing table. In other words do each of those feeders have to be sized by the general ampacity table rather than using the reduced sizes normally allowed for residential buildings? Obviously I think that is true but I wanted to check with the rest of you to see if I'm reading that correctly.
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Tom Horne
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