i thought if you were using a 30 amp you had to use #8 not #10 i have a chart and have to check it to be sure. but doing a project also and if i remember correctly #8 is for a 30amp. someone correct me if thats not right
Consider yourself corrected:#10 for 30 amp, #8 for 40 amp. Unless a long cable run requires correction for voltage drop.
Coastal South Carolina