How far from the outlet can the GFCI be?

  1. Is there a safe maximum distance between the main panel and the home it protects?

  2. Is there a safe maximum distance between a GFCI breaker and the outlet it protects?

  1. I don’t understand the question. The panel must be IN/ON the home it protects. Any other situation would be absurdly cumbersome.

  2. No, not really. If the GFI protection is remote, a sricker should be used on what it’s protecting.

Square D’s answer

Page 2

The service disconnect has to be on the property but not necessarily on a building. Each building does require a disconnect though. I have inspected “may pole” instlations where they have a 3r service disconnect on a pole in the middle of the property and radial feeders going to each building. That is best for mitigating voltage drop.

The “length” on the GFCI circuit is to reduce niusanse tripping, not a safety issue. If the circuit is too long they fear you will get too much coupling to ground. I have not seen that at my house. I have a long circuit in my screen cage hitting all the lights and a long circuit down to my boat lift. I don’t have a tripping problem on either of them. Both have several hundred feet of wire in pipe.

I answered #1 the way I did because he specifically stated main “panel”, not main disconnect. Now I wonder which he means.

Like Greg said though, even if there is a “main disconnect” somewhere on the property, the structure MUST have it’s own service disconnect on it or just inside of it.

The Cliff Notes version of the Square D doc Donald cites above:

*NOTE: To minimize nuisance tripping:

• Do not connect circuit breaker to swimming pool equipment installed before adoption of the 1965 National Electrical Code.

• Do not connect circuit breaker to electric ranges or clothes dryers
whose frames are grounded by connection to a neutral conductor.

Do not connect circuit breaker to more than 250 ft. (76 m) of load
conductor for the total one-way run.

This was a situation in which a sub-panel (no GFCI breakers) for a detached garage was located on another building with approximately 100 feet between the sub-panel and the garage.
Underground conductors ran to 2 GFCI outlets in the garage which protected garage wiring. I was wondering if the breakers in the sub-panel could be replaced with GFCI breakers to protect the garage.

Now that would be inconvenient!

Are you saying that there is a set of feeders and two branch circuits feeding this garage?

  1. So - to be sure I understand - you cannot (for example) separate outlet and lighting circuits to the garage, you would have to run feeders to a load-side panel in the garage instead.

  2. Are any of the conditions listed in 225.30(A-E) likely relevant to Home Inspectors?

Are you by any chance the Mike Whitt who grew up Roseland?

(A) Special Conditions. Additional feeders or branch circuits shall be permitted to supply the following:
(1) Fire pumps
(2) Emergency systems
(3) Legally required standby systems
(4) Optional standby systems
(5) Parallel power production systems
(B) Special Occupancies. By special permission, additional feeders or branch circuits shall be permitted for the following:
(1) Multiple-occupancy buildings where there is no space available for supply equipment accessible to all occupants, or
(2) A single building or other structure sufficiently large to make two or more supplies necessary.
© Capacity Requirements. Additional feeders or branch circuits shall be permitted where the capacity requirements are in excess of 2000 amperes at a supply voltage of 600 volts or less.
(D) Different Characteristics. Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or phases or for different uses, such as control of outside lighting from multiple locations.
(E) Documented Switching Procedures. Additional feeders or branch circuits shall be permitted to supply installations under single management where documented safe switching procedures are established and maintained for disconnection.

Yes, 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.

In 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.
225.39 states what size these circuits must be.

None of these sections would apply to a residential application except the possible of fire or generator circuits.

I was born in High Point NC and moved to Wilkes County NC to live out the first 19 years of my life. At 19 I moved back to High Point and have lived within 50 miles of this area till this day.
Rumor has it that some of my ancestors may have ended up at area 51 a few years back but if they did the government is keeping a tight lid on their where-a-bouts.

Wait a minute you said Roseland, NC not Roswell Nv., LOL

I do have distant relatives scattered all over the state of NC and Va. The family moved to the mountains of Va. in the 1800s and migrated south over the state of NC for the next century.
Over the past 50 years my brothers and first cousins have moved as far West and North as Maple Falls, Washington and as far East and South as Key West Florida.
No I am not this man although I have been there.

Sorry… one set of feeders exist only. They run from a Non-GFCI sub-panel out back of the main building to the double garage (serving separate units of a duplex). Also on this circuit are exterior walkway lighting for the duplex structure. Feeders run to two GFCI’s in the garage (no separate sub-panel), and then to a couple of outlets, switches, lights and overhead door openers, one at each side of the garage.

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

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

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

What more can you expect from a tarheel? :roll:

Greg are the two even close to each other? :wink:

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…:wink:


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…

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?

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.