Why only one feeder to separate buildings?

[kwired]

225.32 and 225.33
i would expect the disconnects to be together and labelled clearly

if your turning off an entire building why not just blindly open all the disconnects that are sitting there beside each-other?

Those sections are about the disconnecting means 225.30 only permits one feeder - unless some of the conditions in the subsections apply. So general rule is only one feeder - but it can have up to six disconnecting means, grouped at same location.

 

[Wire-Smith]

Those sections are about the disconnecting means 225.30 only permits one feeder - unless some of the conditions in the subsections apply. So general rule is only one feeder - but it can have up to six disconnecting means, grouped at same location.

correct i was replying to your

Some of those items may deserve some consideration. Still not going to be too significant of difference in many applications between a 200 amp feeder and a 90 amp feeder.

I think especially on smaller capacity feeders (like at least 1200 amp and less) there is still more safety advantage to knowing you shut off the entire building with that one switch then there is to turn off two or three switches and then find out the hard way that there was another switch that needed to be turned off.

the disco's should be right next to each other, clearly labelled and readily accessible


i cannot come up with a reason that says it is less safe to have multiple feeders, as long as you follow the NEC

 

[Wire-Smith]

if the disconnects were in different locations and not labelled i definitely see a problem with that.

 

[kwired]

correct i was replying to your




the disco's should be right next to each other, clearly labelled and readily accessible


i cannot come up with a reason that says it is less safe to have multiple feeders, as long as you follow the NEC

I was trying to say the same thing I did earlier in this thread - only thing that makes sense to me as to why NEC allows only one feeder to a separate building/structure as a general rule might be if you turned off breaker in building A marked "building B" but didn't realize there was a second one marked "building B", then go to work in building B, not everything is off.

Six disconnects in building B isn't quite the same thing as six disconnects Supplying building B located in building A.

With services we don't have this issue because typically only the POCO has permission to disconnect the supply side, where with a feeder it isn't just electricians that are being protected by the rule but anyone that has access to the feeder disconnecting means.

 

[Wire-Smith]

don't the disconnects have to be at the building served?

225.32

 

[Wire-Smith]

also 225.37 you need a plaque/directory at each disconnect denoting all others

 

[Wire-Smith]

OP do the feeders have there disconnects grouped at the building served? (main breakers?), is everything clearly labeled and following 225.37 (at both buildings preferably in my opinion) and what are the two feeders exactly feeding?

 

[LarryFine]

Since it's sort of on topic, does the same apply to two circuits feeding a detached structure?

I'm proposing a 60a 240v car-charger circuit to a detached garage that already a has a 120v lighting circuit.

Any issues with two circuits supplying a separate building? Must either or both have a disconnect at the point of entry?

 

[packersparky]

I agree with you in that is sort of doesn't make sense that you can have two to six sets of service conductor (connected to same source) and land in two to six service disconnecting means (grouped in one location) but at same time can't have two to six feeder sets supplying same building even if the disconnecting means are all grouped in one location. You can have a single feeder that supplies two to six disconnecting means in that same building though.

Only thing I can come up with that sort of makes sense is if you shut off a feeder breaker at the garage marked "house" and didn't realize there was a second feeder to the house you might think everything in the house is dead though it is not.

I see 230.2 as considering it a single service where 2 (and no more) underground laterals supply one building where they come from the same transformer and are connected at the supply end and not at the load end. I don't believe that more than 2 laterals is allowed.

 

[Little Bill]

Since it's sort of on topic, does the same apply to two circuits feeding a detached structure?

I'm proposing a 60a 240v car-charger circuit to a detached garage that already a has a 120v lighting circuit.

Any issues with two circuits supplying a separate building? Must either or both have a disconnect at the point of entry?

Same thing for branch circuits as feeders.

II. Buildings or Other Structures Supplied by a
Feeder(s) or Branch Circuit(s)
225.30 Number of Supplies. A building or other structure
that is served by a branch circuit or feeder on the load side
of a service disconnecting means shall be supplied by only
one feeder or branch circuit unless permitted in 225.30(A)
through (E). For the purpose of this section, a multiwire
branch circuit shall be considered a single circuit.

 

[packersparky]

Since it's sort of on topic, does the same apply to two circuits feeding a detached structure?

I'm proposing a 60a 240v car-charger circuit to a detached garage that already a has a 120v lighting circuit.

Any issues with two circuits supplying a separate building? Must either or both have a disconnect at the point of entry?

I believe that you have 2 branch circuits, and i think it depends on if your AHJ considers 120 volts and 240 volts as "different voltages" in accordance with 225.30(D). That may be a stretch as they are supplied by the same system. Both would need a disconnect either outside or nearest the point of entrance per 225.31 and 225.32.

 

[LarryFine]

Well, the new circuit will be 240v only, no neutral, and the existing is a single 120v 15a circuit. That could qualify as different characteristics.

I did plan on a 2p disconnect and a "master" toggle switch for the lighting circuit.

Otherwise,, we'd need to abandon the existing circuit and run a feeder greater than 60a, add a neutral, and install a panel and grounding. :rant:

 

[packersparky]

Well, the new circuit will be 240v only, no neutral, and the existing is a single 120v 15a circuit. That could qualify as different characteristics.

I did plan on a 2p disconnect and a "master" toggle switch for the lighting circuit.

Otherwise,, we'd need to abandon the existing circuit and run a feeder greater than 60a, add a neutral, and install a panel and grounding. :rant:

I guess it's time to practice your skills of persuasion.

I believe in either case you would need a grounding electrode system installed at the building. The exception to 250.32(A) only applies when a single circuit supplies the building.

 

[kwired]

Since it's sort of on topic, does the same apply to two circuits feeding a detached structure?

I'm proposing a 60a 240v car-charger circuit to a detached garage that already a has a 120v lighting circuit.

Any issues with two circuits supplying a separate building? Must either or both have a disconnect at the point of entry?

As mentioned but sort of omitted in most of the converation 225 part II addresses both branch circuits and feeders.

I see 230.2 as considering it a single service where 2 (and no more) underground laterals supply one building where they come from the same transformer and are connected at the supply end and not at the load end. I don't believe that more than 2 laterals is allowed.

Correct. One service is allowed to be multiple conductor sets that originate from same source. A feeder is different in that we have a supply side disconnecting means on feeders.

Well, the new circuit will be 240v only, no neutral, and the existing is a single 120v 15a circuit. That could qualify as different characteristics.

I did plan on a 2p disconnect and a "master" toggle switch for the lighting circuit.

Otherwise,, we'd need to abandon the existing circuit and run a feeder greater than 60a, add a neutral, and install a panel and grounding. :rant:

Might be able to do that in some places. Many still see it not being different characteristics when the source is the same for both. Another similar example is supplying single phase and three phase (originating from same secondary) to the separate structure

 

[Dsg319]

Just for my minds sake I seen this thread and have a question. Say you have a 400amp service (single family dwelling). No 400 amp main only 2-200amp mains right off the meter.

I would never do it like this but just for my knowing are you allowed to feed say 1story of the house with the one 200amp breaker than say the basement off the other200amp breaker. Or must you only go off of one?

 

[electrofelon]

Just for my minds sake I seen this thread and have a question. Say you have a 400amp service (single family dwelling). No 400 amp main only 2-200amp mains right off the meter.

I would never do it like this but just for my knowing are you allowed to feed say 1story of the house with the one 200amp breaker than say the basement off the other200amp breaker. Or must you only go off of one?

I am not clear if you saying you have 2-200 amp breakers/disconnects at the meter, or NO breakers /disconnects at the meter. If the latter, then that installation is per 230.40 exception #2, but the service disconnects must be grouped. The wording and structure isnt the best but see 230.71 and 72. If the former, then you have feeders and you can go wherever you want with each.

 

[kwired]

You can have up to six mains. Must be grouped together.

Beyond those is no longer service conductors, is feeders. If supplying only same structure you don't need to have a main breaker at the subpanel(s) but is not prohibited either. This only applies as long as the feeder breaker is at or less than the rating of the panel it is protecting though.

 

[Little Bill]

Since this thread is over 2 years old, it should have been closed. If anyone wants to start a new thread to continue the discussion, feel free to do so.