What do you intend to do with the Sauna? Is this a 4 wire feeder to the sauna?
i have a shut off switch installed already so either power will go to the sauna or the workshop as i need it.
it's fed by 2 lines i'm assuming 110v 30 amp each
each lines has 3 wires the wires are 10 gauge
How many breakers are in the panel that feeds the sauna?
Is it a single breaker dual pole? Are there 2 NM cables, romex, that feed this panel from the main panel? Does the black wire from each cable connect to the 30 amp breaker, one to each pole?
so the line goes like this. Main breaker in house->sub panel in house -> to sauna/switch-> possibly to workshop panel
the breaker is like this one
Do I understand correctly that you have 2 cables each one 10/2 with ground that feed the sub panel near the sauna?
the 10/2 goes from the house sub panel to the sauna currently. I want to take the 10/2 extend it and have it go into a shed i'm converting into a workshop.
in order to distribute the power better i thought it would be best to put in a small panel in the workshop and have the workshop power come off the panel so i can have 15/20 amp circuits
So the suana is 240 volts, not 120/240. You have a black, a white and a ground, that's all.
not 30 amp
You have no neutral and therefore no 120 volts available. You need a 10/3 with ground to give you both 120 and 240 volts. It MUST be 4 wire. The code requires this.
Do you have room for another 2 pole breaker in the main panel?
I suggest running a new 4 conductor feeder from the main panel to the workshop and you will have both 120 and 240 volts available. If you want only 120 volts then either a 3 or 4 conductor feeder would work. With a 3 conductor feeder you would feed both poles of the main breaker with the same 120 volt line.
ok i see. let me go verify everything real quick to make sure i don't have any other questions.
Your outbuilding will be treated just like a service on a house, main breaker and ground rods are both required. The amperage of the breaker is not important, it is a service disconnect and could be 100 amps while fed by a 30 amp feeder. Square D panels are available with 20 spaces and a main breaker for just over $50 here at Home Depot or Menards. A smaller panel could be used as well with an installed main breaker backfed with a retaining device for the main breaker. It all depends on what you want for circuits in the workshop.
You can always come back here and ask more questions even after we finish here for now. I will always be willing to help you.