wire recommendation

[buildintechie]

I ran 2-2-4-6 direct bury wire for my 100amp sub panel.

I've got separate circuits run to my DC, Air Compressor, Air conditioner, computer, and freezer. I then ran a separate circuit along each wall of my shop, along with one for lighting, and an outlet outside.

I'll never run more than one tool and a DC at the same time, plus the lights, computer, etc.

[Earl]

Thanks guys I guess that was question that shouldn't have been asked without telling you all the specs. I will be running the wire from my main box that is outside and it looks like I will be going around 80ft+ to the building. There will be a sub box in the building, I like for my breakers to be close. I don't have a big shop only small power tools - table saw; pancake air compressor; table top drill press; SS; wood lathe, an OSS and the lights - only one machine will be running at any given time - unless I need to turn the WorkSharpe on while I am turning to touch up a tool, oh and I do have a radio and plan to get a small dust collector in the future

You said above you are running it from the main box which is outside. Do you mean you are planning to connect to the service entrance where the meter is located? If so, you will need to install a disconnect next the service entrance and attach your feed to the disconnect. Disconnects are required when your panel is more than 10 feet or so from the service entrance (check with your local code for the specific details on distance).

[FlyingRon]

There is no "local CODE" in either Virginia or North Carolina that specifies any specific distance requirements between where the service conductors enter the building and the service disconnect. In both states, the local municipalities are supposed to be following their state level adoption of the NEC. I don't see anything in either state that expresses such a limit. That's not to say that some yahoo local inspector may choose to invent one.

But PChristy is going to have to explain what he means by "main box." If he's talking about something other than the main panel, he's probably got some serious problems with the design he's envisioning. If the "main box" is his main panel (including or after the service disconnect) and he's just pulling a subpanel, then that's less of a concern.

[Earl]

I agree, I have not seen a specific distance in the code section 230.70, but a quick web search shows lots of references to local inspectors requiring external disconnects, just like my county did when I expanded my kitchen and increased the distance between the meter and main panel.

[ehpoole]

Generally, the disconnect requirements you all are discussing (if I'm following your discussion correctly) govern the maximum distance between the service entrance (meter) and your first load center (the main breaker panel) or disconnect (230.70a - as short as possible). The disconnect requirements are meant to insure that this unprotected and always 'hot' length of feeder can be properly disconnected in the event of fire, accidental damage or other emergency since there are no circuit breakers to protect this run (only the fuses at the transformer). Because this segment is always hot, there is a desire to keep such runs as short as possible in the absence of a disconnect switch located at or near the meter. Without the disconnect, the only way to kill the power to this feeder is to either pull the meter or disconnect at the transformer, neither of which are available options for the homeowner. In instances where the meter and main load center are a combined panel (not uncommon these days), this requirement is entirely irrelevant.

Such requirements should be irrelevant to the discussion with regard to the proposed shop run because the feeder line supplying power to the shop subpanel will itself be serviced by a 60-100A breaker located in the main load center (breaker panel). This breaker also constitutes a service disconnect in this example and can be used at any time to de-energize the feeder line supplying power to the shop subpanel. At no time should the shop subpanel be drawing power directly from the meter (except in the case of a combined meter/load center -- in which case it is the load center portion that the shop subpanel will be drawing its power from, NOT the meter side).

Where I think there may be some confusion is with regard to 225.31 requiring a disconnect at the point where a service conductor enters a second building (and fed from another). However, this can be satisfied by choosing a subpanel (for the shop) with an integral main breaker of its own. This main breaker would then serve as the service entrance disconnect for the building (shop). How this is enforced may vary some based upon locality because it is a somewhat confusing requirement with no clear reasoning since it duplicates the disconnect provided by the over-current device (breaker) in the upstream load center. The amperage of your "disconnect" breaker should be equal to or greater than the over-current protection (your breaker in the main panel) since it's purpose is that of a disconnect and NOT an over-current protection device.

HTH

[ScottM]

Philip, like Jeff I ran 2-2-4 from my house box to a 100 amp panel in the shop. My run was 110 feet. It is aluminum wire but that is all you need for a supply line. Copper would cost you many times the cost. Back in 2010 it only cost a $1.05 per foot. DO NOT go to Lowes or the other BORG stores to price it. I went to an electrical supply shop (City Electric Supply) and they beat the BORG's on the supply wire and most of the other components.

[FlyingRon]

Yes, note the parallel conduit. It is unsafe and illegal to run most data/TV wiring in the same conduit as the power.