wire

[tim]

Went into a couple of houses latley and noticed that the conducters feeding the panel were 2 0/. These panels are back to back with the meter. Panels are 200 amp main rated. Shouldn't this wire be 3 0/? Also, I do not believe that the you should reduce the neutral. Any thoughts?

Thanks Tim

 

[ryan_618]

Re: wire

If you are talking about copper it would comply. If you are talking about aluminum, it would need to be 4/0.

See Table 310.15(B)(6)

 

[william runkle]

Re: wire

Tim why not reduce the grounded conductor? It will only carry the unbalanced load of the ungrounded service conductors.

 

[stew]

Re: wire

Tim I think you must be looking at table 310.16 to draw your conclusion that 3/0 is correct. Refer instead to table 310.15(B)(6) where you will find the correct wire size that is allowed to be used on residential service entrance conductors.As the grounded conductor carries on ly the unbalanced portion of the load it is sized accordingly. a grounded conductor is generally one size smaller than the ungrounded conductor as in triplex .4/0-3/0 al or 2/0-1/0 cu for a 200 amp service. i believe it is sized at 70% of the ungrounded conductors.