I would recommend 6ga for runs under 75ft, 4ga for under 150, and 2 for under 225.
Ok #6 is good for 65 Amp @ 75degC. I know the table for thhn wire shows #6 is good for 75 Amp @ 90degC. But you can not use that column. You have to use the 75degC column. The reason for using the 75degC column is the terminations (wire lugs) (circuit breakers) (wire nuts) (etc.) are only rated 75degC. not 90degC. You have to use the weakest link as the max. If one of the terminals in the circuit were rated 60degC then #6 thhn wire would be good for 55amp @ 60degC. You must not run hotter than the rating!
(by - tbcguy) I am a Licensed Electrician, and have been in the trade for 22 yrs.
As mentioned above you Cannot use the 90degC column for the above mentioned reasons.
** Also note the 65amp rating is the maximum @ the 75degC column, but the STANDARD size "Breaker" is 60 amps, so you would drop down the rating of the 6 awg wire to 60a maximum load.
As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
In order to safely run 30 amps of electricity, a minimum of a #10 gauge wire is needed. For longer runs of wire, #8 gauge is better.
A 100 amp residential panel requires that you use AWG # 3 service entrance wire.
30 amp 220v circuit requires #10 wire
You need to know the current to determine the wire gauge.
The lower the voltage the larger gauge wire you will need to get the same power.
2 or 4
10-2 wire refers to 10 gauge, 2 conductor wire. Youshould use wire that is 10 gauge or larger (8 gauge, 6 gauge, 4 gauge, 2 gauge). The larger the wire, the more it will cost. most people install using the smallest size permitted, which in this case is 10 gauge. The are specifying the wire size to ensure that you do not connect the air conditioner to electric power using wire that is two small. If you are having problems with this type of question, you should consult an licensed electrician for help in connecting your air conditioner.
A good wire gauge for car radios is 18 gauge. This wire runs between the radio and its power supply from the vehicle.