Sparks you really can't run three circuits to a detached building.
225.30 Number of Supplies.
Where more than one building or other structure is on the same property and under single management, each additional building or other structure served that is on the load side of the service disconnecting means shall be supplied by one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.
There are some allowances for more than one circuit but it is unlikely they will fit for you.
You need to look at 225.30 to 225.40
You need disconnects and grounding electrodes. If you have to have three circuits you will be installing a feeder with a panel at the garage.
Is it possible you could do it with just two circuits?
One multiwire branch circuit will provide two circuits and does not require the grounding electrode.
Bob
