split AC suction line cold & liquid frostiong sweating ?

Had some one ask me to take a look at a split ac unit the had set up the had brought the unit used & was pumped down with r410a refrigerant. It had lowside pressure of 15 bar when unit was started low side pressure began to raise very fast whilst liquid line frosted & suction was really cool the unit was blowing cold air the unit was admittedly shut down.

But the liquid line frosting suggest restriction why is the suction really cold is this due over charge?