How far from the outlet can the GFCI be?

[Mike Whitt]

Originally Posted by Greg Fretwell

Mike, the aliens landed in Roswell NM, not Nevada.

See I told you I was never more than 50 miles from home and home is in NC.

What more can you expect from a tarheel?

Greg are the two even close to each other?

[Paul W. Abernathy]

Or a better way to look at it.....

The Service Conductors END at your main OCPD in your main distribution panel of your dwelling or the first OCPD in the system.

The Feeders go out to other panelboards ....AHHHHH....but they dont ALWAYS have overcurrent on both ends.....ala remote distribution panel within a dwellling...( main lug only panel )....to which then your "Branch Circuits" go out to your utilized equipment...

Ok....did I make it more clear...or more confusing...

[whandley]

Hey Greg;

I run into newer condominium projects where the meters and main service disconnects are located in other detached structures, away from the subject unit. The subject unit has a sub panel with way more than 6 throws.

I did a property in Laguna Beach yesterday with 2 detached houses and a guest studio. (1) 200 amp service disconnect was present at house #1. House #2 and the studio were supplied via the 200 amp service with 100 and 120 amp sub panels respectively. Owner had finaled permits on all of it....

[Kenton H. Shepard, CMI]

Originally Posted by Mike Whitt

These are not feeders they are branch circuits.

Feeders will always have overcurrent on both ends.

Branch circuits will have overcurrent on the line end.

Service conductors will have overcurrent on the load end

In that case the non-GFCI overcurrent device is located probably 150 feet from the garage on the back side of a separate building. The AHJ made it sound like the GFCI installed at the start of the garage circuit was acting as an overcurrent device. A GFCI acts by sensing imbalances in current and opening the circuit when the differences in aperage beome too great. So why isn't it an ovecurrent device?

[Mike Whitt]

A ground fault is when the hot comes into contact with the ground or in other words the hot is faulted to ground.

Overcurrent is when there is more current being drawn on a circuit than the circuit is rated to carry.

If a 15 amp GFCI device is installed and there is an imbalance of .05 amps between the hot and ground the device will open. It opens at 14.95 amps less that what the circuit is rated in the event that the hot becomes faulted to ground.

The same 15 amp circuit that is protected with a GFCI device and loaded with enough current draw that is balanced between the hot and grounded (neutral) to the point of the opening of the breaker will not trip the GFCI device.

A GFCI device will not open in an overcurrent situation it opens only in ground fault.

The requirement to have a disconnect at a remote building has been the requirement for many code cycles but one that is being overlooked even today.

[Paul W. Abernathy]

Originally Posted by Mike Whitt

The requirement to have a disconnect at a remote building has been the requirement for many code cycles but one that is being overlooked even today.

Yes indeed in a remote building or structure environment.....but not when within the same dwelling.....that is where you run into the "Remote Distribution Panel" with MLO terminations in many cases....and is generally where some get confused.....since the feeders can be protected at the main panel...and only branch circuits from the remote distribution panel require OCPD's at that panelboard and enclosure.

[Greg Fretwell]

GFCIs are not overcurrent devices and they will not reliably open in a bolted fault. Quite often it simply destroys the GFCI (shorted). If you do trip a breaker on a GFCI circuit, be sure to test the GFCI when you restore power. It may not work.

[Paul W. Abernathy]

BUT it is important to know that a GFCI Breaker is indeed an OCPD as well....it serves as both ( that was my shameless plug for Eaton® )

[Greg Fretwell]

True Paul, sorry I was referring to the "device" unit.
It is just the relay they use in the device that can't deal with a bolted fault. The breaker style actually ends up tripping the breaker contact that is rated for AFC.
http://members.aol.com/gfretwell/gfci.jpg

[mthomas2]

OK, now I am confused.

We have:

“Where more than one building or other structure is on the same property and under single management, each additional building or other structure that is served by a branch circuit or feeder on the load side of the service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E).”

And we have:

“ a multiwire circuit can be installed to a detached garage as long as there is a disconnect that is rated as service equipment installed at the garage.
Article 225 was introduced to the NEC in the early 1970s and the requirement for a disconnect was entered in the 1993 code cycle, 225-8 with 225-8(c) requiring the disconnect to be rated as service equipment.”

“today’s code (2005) 225.36 has an exception which states;
Exception: For garages and outbuildings on residential property, a snap switch or a set of 3-way or 4-way snap switches shall be permitted as the disconnecting means.

What we need to understand is that the part of this exception that limits the use of these switches is “A snap switch” and “A set of 3-way or 4-way snap switches” which clearly denotes a single switch or a single set of 3-way or 4-way switches.


If only a single disconnect means is allowed at the garage, how can we have multi-wire circuits (say, for outlets and lighting) run to it?

[Mike Whitt]

Originally Posted by mthomas2

OK, now I am confused.

When running electricity to a remote building on the same property there are several rules that apply to the circuit(s).
When I say remote building I am including everything from pump houses, out buildings and detached garages all the way up to and including separate industrial buildings.

Any building that is remote to the one on which the service is attached is required to have a disconnecting means installed. In residential applications this disconnecting means is allowed to be a snap switch or a set of three ways when only one circuit is installed.

In 225.39 the size of the circuit supplying the remote building is mandated to be one of these;
1) For installations to supply only limited loads of a single branch circuit, the branch circuit disconnecting means shall have a rating of not less than 15 amperes.
2) For installations consisting of not more than two 2-wire branch circuits, the feeder or branch-circuit disconnecting means shall have a rating of not less than 30 amperes.
3) If the remote building is a dwelling, the feeder disconnecting means shall have a rating of not less than 100 amperes, 3-wire.
4) For all other installations, the feeder or branch-circuit disconnecting means shall have a rating of not less than 60 amperes.

225.30 requires that each additional building or other structure that is served by a branch circuit or feeder on the load side of the service disconnecting means shall be supplied by only one feeder or branch circuit.

225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.
It is here that we find the exception for switches. Pay attention to the “A” which is a singular switch or set of three ways with a four way in the middle.
Exception: For garages and outbuildings on residential property, a snap switch or a set of 3-way or 4-way snap switches shall be permitted as the disconnecting means.

It doesn’t matter if it is a single 120 volt circuit or a multiwire circuit the requirement to have some way of disconnecting all ungrounded conductors must be installed at this remote building.
If it is a multiwire circuit and the multiwire circuit is broke into two separate circuits in this building such as lights and receptacles then the disconnecting means is required to be rated at 30 amps.

To install two 120 volt two wire branch circuits, one for the lights and the other for the receptacles is a violation of 225.30. Installing a 240 volt multiwire circuit and splitting it in the building without a disconnect is a violation of 225.31.

The safety issues are; should something go wrong in this remote building there needs to be an accessible means to open all hot conductors in a hurry instead of running around trying to find a remote panel and then figuring out just what turns the power off.

Does this help?

[Greg Fretwell]

A multiwire circuit is still considered one circuit and you disconnect it with a 2 pole switch as a general rule. I suppose you could use 2 single pole switches in a dwelling if there are no 240v loads and no shared device yokes.

[mthomas2]

Originally Posted by Greg Fretwell

A multiwire circuit is still considered one circuit and you disconnect it with a 2 pole switch as a general rule. I suppose you could use 2 single pole switches in a dwelling if there are no 240v loads and no shared device yokes.

This is where I'm starting to get confused, the case I was thinking of was a multiwire (three wire) with two 120V circuits on a shared neutral (say, on for lights, and one for outlets) originating at a two-pole breaker at a service or load-side panel in the main structure...

Perhaps we can back up a step:

1) The circuit to the garage can be a single 120V circuit, with the OCPD at a service or load side panel in the main structure.

2) The circuit to the garage cam be feeders to load-side panel at the garage, from a service or load side panel at the main structure.

3) The circuit(s) to the the garage can also be ????? (if anything).

Once I understand if these is - or is not -a third case, I will have an easier time understanding the disconnect requirements.



2) The garage can also

[Mike Whitt]

Originally Posted by mthomas2

This is where I'm starting to get confused, the case I was thinking of was a multiwire (three wire) with two 120V circuits on a shared neutral (say, on for lights, and one for outlets) originating at a two-pole breaker at a service or load-side panel in the main structure...

Being that this is supplying two circuits the disconnect at the garage will be required to be not less than 30 amps. There is no such thing as a 120 volt multiwire circuit.

Originally Posted by mthomas2

Perhaps we can back up a step:

Originally Posted by mthomas2

1) The circuit to the garage can be a single 120V circuit, with the OCPD at a service or load side panel in the main structure.

And the disconnect located at the garage can be a single pole switch or a set of three ways with one three way at the garage and the other at the house. The switch(es) must turn off all power going to the garage.

Originally Posted by mthomas2

2) The circuit to the garage cam be feeders to load-side panel at the garage, from a service or load side panel at the main structure.

Feeders can land in a panel at the garage as long as the panel is rated as service equipment or they can land in a disconnect such as a disconnect with fuses as long as the disconnect is rated as service equipment.

Originally Posted by mthomas2

3) The circuit(s) to the the garage can also be ????? (if anything).

Any circuit at the detached garage must have something to disconnect the circuit from the garage.

Originally Posted by mthomas2

Once I understand if these is - or is not -a third case, I will have an easier time understanding the disconnect requirements.

In all cases a means to disconnect all the hot conductors MUST be installed.

Originally Posted by mthomas2

2) The garage can also

be required to have a grounding electrode installed 250.32

Originally Posted by Greg Fretwell

A multiwire circuit is still considered one circuit and you disconnect it with a 2 pole switch as a general rule. I suppose you could use 2 single pole switches in a dwelling if there are no 240v loads and no shared device yokes.

A multiwire circuit could be opened with a two pole switch as long as it is an individual branch circuit supplying only one circuit.

The use of two single pole switches will not work at the house due to 225.31 and they will not work at the detached garage due to 225.30, and 225.39.

[Greg Fretwell]

225.33(B) Single-Pole Units. Two or three single-pole switches or breakers capable of individual operation shall be permitted on multiwire circuits, one pole for each ungrounded conductor, as one multipole disconnect, provided they are equipped with handle ties or a master handle to disconnect all ungrounded conductors with no more than six operations of the hand.

It is language like this in the NEC that makes you shake your head.

They say you can use up to 3 single pole switches (assuming up to 3p wye)... then they say handle ties ... then they say no less than six operations. It seems to me 2 single pole switches without handle ties only requires 2 operations.

Since you can't have more than one circuit (a multiwire is one) I don't see any case where a multiwire can't be single pole switches unless you have the 240v load or land on a single yoke.
All that said I still like to see the 2 pole switch and that is what I always got.