I've read various posts concerning the 10 foot rule where a disconnect is needed at the meter if the load panel is more than 10 feet from the meter. This is of interest to me since I would like to relocate my load panel. Question #1-Am I interpreting this correctly?

Question #2- If using a main breaker load panel, what difference does it make how far the panel is from the meter, as long as the panel is accessible? Or……maybe this was answered and I missed it…….. leads to…..

Question #3-Does this rule apply only if the wires from meter to panel are in the interior of the house? Example-My mother's town home, new construction, four years old, built on a slab, in a Chicago suburb. The main breaker load panel is in the garage, and the meter is located on the opposite exterior wall, appx. 40 feet from the panel. It is a standard meter box used for underground utility feeds, and the sheet metal enclosure has no access points. I did some work in the upper crawl space and didn't seen any feed wires, so I'm assuming the wires from the meter to the box run in/under the slab. Question #4 :confused: No meter disconnect required since the wires not physically in the interior, or could there be local waivers for this type of install?

The reason the length of exposed conductors from the meter to the main in a panel need to be considered is there is no overcurrent or short circuit protection, other that what may be at the utility side, and that is usually only on the high voltage primary of a transformer.

The codes states the service disconnecting means shall be "inside nearest the point of entrance of the service conductors." This is found in Section 230.70 (A) (1).

The "unwritten 10 foot rule" comes from a tap rule for smaller conductors fed by a much larger breaker or fuse. Some utilities even refer to 10 feet.

Conductors that run under slab are considered outside, so the only portion to be concerned with is the riser from the floor to the panel.

The actual length of exposed conductors is always up to the local inspector, the object is to keep exposed service conductors as short as possible.

Thanks TK-I see the 10 foot rule is "unwritten" but your explanation clears up the reasons for doing it. One point for my clarification--when you refer to "exposed conductors" do you mean in the walls, interior of house, etc, as opposed to wires, say, in the slab? Are wires from the meter to panel considered exposed, per electricians/NEC definition if they are run in conduit, but in the interior of the house? I'm assuming (usually a mistake) they would be since I don't think any code would allow meter to panel feeds to be installed "as is"

Service entrance conductors will only be considered as being outdoor if they truly are outdoors, or under at least 2 " of concrete. Under a slab they are considered as outdoors.But once they exit the concrete, then this 10 foot rule comes into play.

There was a photo of a job someone did in a factory, the electrician installed the main service switch about 50 feet inside , with the conduit exposed in the air above the floor. The inspector could only require that a concrete pour be added around the conduits, damnedest thing we ever saw, but the contractor was able to leave the main switch where he put it, the conduits were now protected.

No inspector will ever admit to 10 foot, but if the conductors are 9 foot they will allow it, if 11 feet, then the remedy will be to have a main breaker outdoors, usually at the meter, to protect these wires.

Where in your example the wires rise out of the floor, and are exposed only a few feet to the panel, this would be allowed, however, many inspectors would require steel conduit, or at least nail protective plates where the conduit passes through framing members.