HELP I have a 480/277 panel one leg is drawing too much. L1 & L2 are ok but L3 is way off! what is the math to fine out how far off L3 is? like 10% 20%

 

If say the current in L1 and L2 is 50 Amps and in L3 is 80 Amps then the current in L3 is:

[(80-50)/80]*100% greater than the current in L1 and L2.