Articles 225 and 230- Detached Gargae

[david]

It may not happen here, buy it is my hope that we end up at a common point. Hopefully, that the service has to be sized to handle the calculated load.

Since the service already has to be sized to handle the loads associated with the building it would be pointless to add an additional supply unless we move into one of the exceptions in articles 230 and 225 or special provisions found in other sections of the NEC.

I also think it is a more reasonable approach that article 225 is laid out, that the service(S) (one of each type allowed) is supplied to the premise under single management, and from the load side of the service (S) disconnect location additional buildings and structures are supplied by a single feeders or branch circuit..

 

[Dennis Alwon]

Of course the service is sized for the load but it only will have to be sized for the load of the dwelling not the entire building. I am sure that the service would be able to handle the garage also but the customer may not want the electrical usage going thru the apt. meter.

As I said this is more hypothetical but I could see this as a real situation somewhere.

So if there were a service to the building feeding an apt upstairs and a separate meter feeding downstairs it seems like you would be okay with it. So why is there such an issue with a feeder being the second source of power. Actually art 225 allows this with a 3 way switch for lighting at the garage that may be fed at the main dwelling. This of course could be a feeder and a branch circuit feeding the garage-- a bit different.

 

[david]

Of course the service is sized for the load but it only will have to be sized for the load of the dwelling not the entire building. I am sure that the service would be able to handle the garage also but the customer may not want the electrical usage going thru the apt. meter.

As I said this is more hypothetical but I could see this as a real situation somewhere.

So if there were a service to the building feeding an apt upstairs and a separate meter feeding downstairs it seems like you would be okay with it. So why is there such an issue with a feeder being the second source of power. Actually art 225 allows this with a 3 way switch for lighting at the garage that may be fed at the main dwelling. This of course could be a feeder and a branch circuit feeding the garage-- a bit different.

It is not a big issue for me personally, and in your example I do not think the garage area would add any additional calculated load to the dwelling

And as you pointed out the tenant could not be expected to pay for loads not associated with the dwelling and in fact a house panel would be needed.

Generally a house panel means a second service entrance, and I could see approving it as you laid it out based on special permission using Different Characteristics. Additional services shall be permitted for different voltages, frequencies, or phases, or for different uses, such as for different rate schedules. Since a non- metered supply would certainly qualify as a different rate schedule than a metered supply

I do however see why the NEC would and does take a narrow view to limiting the supplies to buildings and in the example of the single family dwelling that I presented would be a good one.

Would you really like to see these type of installations as I described popping up everywhere?

 

[david]

but it only will have to be sized for the load of the dwelling not the entire building.

Please clarify if you mean service entrance or the service has to be sized for the dwelling,

And where do I go to allow the service not to be sized to the loads as calculated in part II of article 220 for the entire building

 

[david]

Again I have to go!!!!!!!!!

 

[Smart $]

...
And where do I go to allow the service not to be sized to the loads as calculated in part II of article 220 for the entire building

First tell us where in Article 220 it says the service calculation must include all loads for entire building.

 

[kwired]

"For the purpose of 230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG and larger, running to the same location and connected together at their supply end but not connected together at their load end shall be considered to be supplying one service."

I can only agree with that if the service is a lateral 1/0 AWG and larger and the service disconnects are grouped.

Are you saying your view is that this set up constitutes a single utility connection (Service)?

Is those your words in quotations or are you quoting something? 230.40 exception 2 says nothing about conductor size.

1/0 would be a minimum size for paralleled conductors, but if they are not joined together at both ends they are not paralleled conductors.

And if you have paralleled conductors the entire set is considered one conductor for this application, but you could have up to six paralleled "sets" and each set has no limit to how many conductors can be in the set.

 

[david]

Is those your words in quotations or are you quoting something? 230.40 exception 2 says nothing about conductor size.

1/0 would be a minimum size for paralleled conductors, but if they are not joined together at both ends they are not paralleled conductors.

And if you have paralleled conductors the entire set is considered one conductor for this application, but you could have up to six paralleled "sets" and each set has no limit to how many conductors can be in the set.

230.2 Number of Services.
A building or other structure served shall be supplied by only one service unless permitted in 230.2(A) through (D).

For the purpose of 230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG and larger, running to the same location and connected together at their supply end but not connected together at their load end shall be considered to be supplying one service.

added--I was making reference to when more than one utility connection can be made to a building without considering the connections to be more than one service.

I think what you are referring to is grouping of service entrance conductors

 

[david]

Is those your words in quotations or are you quoting something? 230.40 exception 2 says nothing about conductor size.

1/0 would be a minimum size for paralleled conductors, but if they are not joined together at both ends they are not paralleled conductors.

And if you have paralleled conductors the entire set is considered one conductor for this application, but you could have up to six paralleled "sets" and each set has no limit to how many conductors can be in the set.

If a utility transformer has a lateral connection to a building with more than one set of service conductors to be considered one service they must be 1/0 or larger and the service enclosures must be grouped to gather at one location added supplying seperate loads

From what you described with conductors smaller than 1/0 are service entrance conductors and must only have one utility connection to the building otherwise you would have more than one service supplying the building

 

[kwired]

OK I am on board with you. I think I learned something here, though I doubt I ever actually violated it before. Not very often would I have ever had multiple service entrance conductors (which could be smaller then 1/0) supplied by a drop/lateral (overhead/underground service conductors after 2011 NEC) etc that was smaller then 1/0. I also can't recall ever running multiple service conductors to a structure that were not at least 1/0 AWG, it would usually be more cost effective to run a larger conductor and tap up to six disconnecting means in those situations then to run multiple smaller conductor sets, maybe a slight chance I may have tapped multiple disconnects from something smaller then 1/0 but I think it is pretty slight chance.

 

[david]

First tell us where in Article 220 it says the service calculation must include all loads for entire building.

Remember I am using the 2008 NEC I am not real comfortable with the 2014 version

 

[david]

First tell us where in Article 220 it says the service calculation must include all loads for entire building.

Remember I am using the 2008 NEC I am not real comfortable with the 2014 version

Can we agree that the conductors from the service utility to premise are the service conductors?

Would you agree that for any given building their is a total KVA calculated load?

Would you agree that a service or a feeder must be sized inacordance with article 220 load calculations?

 

[iwire]

Can we agree that the conductors from the service utility to premise are the service conductors?

I can agree to that.

Would you agree that for any given building their is a total KVA calculated load?

Yes, and that total calculated load can be supplied by one or more sources. They is no requirement that the total calculated load of a building must be supplied from a single source.

Would you agree that a service or a feeder must be sized inacordance with article 220 load calculations?

Yes.

 

[kwired]

Remember I am using the 2008 NEC I am not real comfortable with the 2014 version

If you are using 2008, though not really effecting the basic requirements concerning the topic of this thread, the 2011 had some added definitions in art 100 to the service conductor category. Without going back to a 2008/2011 and going off memory some of the added definitions were:

Service conductors, overhead
Service conductors, underground
Service point

The addition of service point made the definition of the other two necessary. Service laterals and service drops are now the conductors ahead of the service point - and though they are mentioned by NEC they essentially are outside the scope of the NEC as they are conductors under control of the utility. Anything on the customer side of the service point is what the NEC applies to. This was a good change IMO as it clarified what portions of the install was subject to NEC.

 

[david]

Common ground first:
We both agree that when a feeder supplies a building there should be a ?single feeder?( meaning not more than one feeder) supplying the building

Would you agree there is emphases on supplying the building as opposide to a single load in the building (or in your view supplying part of the building) to what load or should I say % I do not know your view on that other than to say it is less than 100%

If the feeder is supplying the building it is feeding branch circuits and 215.1 comes into play
215.1 takes us to 215.2 (B)

Though each article has a scope the code is to be considered in whole, 230.2 boldly states the number of services to be one, and then goes onto state unless A through D. with the statement of the laterals re-emphasizes we are talking about one service. The article goes on to say that when more than one service is involved it will be clearly called out and identified. It was not necessary to have section one buildings supplied with one service , section two buildings supplied with more than one service, section three buildings supplied with two or more service. For the most part codes as laid out for buildings with more than one service are the same as buildings with more than one service.

225.30 Number of Supplies.
?on the load side of the service disconnecting means?

Subject in quotes ?service? sends me to article 230 since article 230 clearly called out unless noted otherwise we are talking about one service.

Why should I let my imagination run wild and believe there are alternate service location when 225.30 does not imply there is any other utility connection to the premise under single management, on the contrary it calls out two criteria, single property , single management of that property.

The building disconnects are accessible to the building occupants. We know why the emphasis on single property, so why the emphasis on single management, that has to do with the service disconnect being out side of the control of the building(s) being supplied occupant(s)

 

[david]

got to back to work, and with the holiday comming i do not know if we can get back to this, enjoy the holiday

 

[iwire]

Common ground first:
We both agree that when a feeder supplies a building there should be a ?single feeder?( meaning not more than one feeder) supplying the building

No, I do not agree it should be a 'singe feeder' that is a design choice not a requirement.

Would you agree there is emphases on supplying the building as opposide to a single load in the building (or in your view supplying part of the building) to what load or should I say % I do not know your view on that other than to say it is less than 100%

Emphases? Maybe, but still not a requirement or mandate.

As far as percentages that would be a design choice, 50/50, 25/75, 99/1 whatever.

If the feeder is supplying the building it is feeding branch circuits and 215.1 comes into play
215.1 takes us to 215.2 (B)

Though each article has a scope the code is to be considered in whole, 230.2 boldly states the number of services to be one, and then goes onto state unless A through D. with the statement of the laterals re-emphasizes we are talking about one service. The article goes on to say that when more than one service is involved it will be clearly called out and identified. It was not necessary to have section one buildings supplied with one service , section two buildings supplied with more than one service, section three buildings supplied with two or more service. For the most part codes as laid out for buildings with more than one service are the same as buildings with more than one service.

225.30 Number of Supplies.
?on the load side of the service disconnecting means?

Subject in quotes ?service? sends me to article 230 since article 230 clearly called out unless noted otherwise we are talking about one service.

Why should I let my imagination run wild and believe there are alternate service location when 225.30 does not imply there is any other utility connection to the premise under single management, on the contrary it calls out two criteria, single property , single management of that property.

The building disconnects are accessible to the building occupants. We know why the emphasis on single property, so why the emphasis on single management, that has to do with the service disconnect being out side of the control of the building(s) being supplied occupant(s)

David, I am pretty much done.

You can jump all over the code but the fact remains each article stands on its own and does not apply to things outside the stated scope of that article.

Looking at the code as a 'whole' as you suggest leads us to the fact that I can supply a building with a service and a feeder.

Any prohibition against that would need to be in article 110.

 

[jtinge]

Common ground first:
We both agree that when a feeder supplies a building there should be a ?single feeder?( meaning not more than one feeder) supplying the building

Not sure I agree with this statement.

If the power supply to the building comes from a customer's distribution system and not a utility, then the supplies can be either feeders and/or SDS's. For an industrial or research type facility, it is not uncommon to have both 480Y/277V and 208Y/120V outdoor unit substations (SDS's) with feeders into the building distribution equipment, and possibly some MV feeders (from a primary distribution substation) to a MV motor/drive or MV power supply.

Wouldn't 225.30 Number of Supplies, (C) Capacity Requirements and (D) Different Characteristics permit this?

 

[iwire]

Wouldn't 225.30 Number of Supplies, (C) Capacity Requirements and (D) Different Characteristics permit this?

This has been brought up before and David seems to think those are exceptions and do not add to the conversation. :huh::?

 

[kwired]

Not sure I agree with this statement.

If the power supply to the building comes from a customer's distribution system and not a utility, then the supplies can be either feeders and/or SDS's. For an industrial or research type facility, it is not uncommon to have both 480Y/277V and 208Y/120V outdoor unit substations (SDS's) with feeders into the building distribution equipment, and possibly some MV feeders (from a primary distribution substation) to a MV motor/drive or MV power supply.

Wouldn't 225.30 Number of Supplies, (C) Capacity Requirements and (D) Different Characteristics permit this?

Mentioned sections would allow feeders with different supply characteristics.

There is similar wording in art 230 for services with different supply characteristics.

Nowhere does NEC specifically address supply being from both feeders and services. ADD: maybe I should say nowhere does it limit supply to be from feeder or service only but not both.

But to have a service and a standby generator (which is going to be either feeder or branch circuit, but not a service) is common, so something is assumed somewhere I guess for that application. And it goes beyond the either you are supplied by service or the generator, if that were the case then "whole house" transfer would be the rule, but you can have a generator that backs up only selected loads, and in such case you can supply those loads from the generator while everything else is simultaneously powered by the service.