How many amps will I havewhen I run 250' of #6-3Wg aluminum

At that distance... at 240 volts, you could have a 20 amp circuit.

You can go far as 60amps on #6 wire

Saloomen,

In point of fact, #6 UF Aluminum is listed as 40 amps. A rule of thumb is that any distance over 100' may increase the size of the cable.

However, the distance and resultant voltage drop cuts that down. That's what MO is referring to.

Littlebird, you are going at this backwards. We need to know what is the amperage you need and the voltage you need it at to get you an accurate cable size.

You can have up to 60amps on # 6 awg

Copper wire, who uses aluminum?

And the rule is over 55ft not 100 with copper

Copper wire, who uses aluminum?Lots of folks. You need to get out more.

And the rule is over 55ft not 100 with copper
Where might I find this rule?

Saloomen,

Let's start in sequence and see if I can clear up your confusion.

1) "You can have up to 60 amps on # 6 AWG."

The ampere rating is partially determined by the type of insulation. Please take a look at Table 310.15 in the NEC. In the Aluminum section, 60(c) column heading you will see the insulation type "UF". Now follow the column down and you will see that 6 AL- "UF" wire is rated for 40 amps.

2)"Copper wire, who uses aluminum?" We are talking Aluminum cable because that's what the poster is using. Please go price 250' of #6 AWG type "UF" cable in copper and then in Aluminum. Now tell me why I would use copper instead of aluminum.

3)"And the rule is over 55ft not 100 with copper" 100' or more is a pure mathematical calculation. There is a general use formula to calculate the amount of voltage drop over "X" distance. There is a more accurate method that takes into consideration the reactance of the metal, but it is not really necessary for our purposes. Regardless, any length below 100' will not cause a change (in general terms). The goal is make sure that the voltage drop of the cable is not more than 3.6% for 120 VAC and 7.2% for 240 VAC. The total voltage drop from the line side to the end of the circuit cannot exced 5%

Can you show me documented proof that your statements are supported? I can provide verification of my statements.