Dear

Whether any minimum amount is kept in PLA current accounts

hi ther is no minimum balance requirement.. only thing it should not be in negetive which means taking a credit which is not actually paid

No minimum balance is required in PLA, on receipt  and acceptance of exciseable inputs required for production of Final excisable output we can take credit on receipt basis.But there should not be Negative balance in RG 23A part11.

thy are correct

There is no need to maintain minimum balance in pla account but you should take care your availabe balance. it should not be lower then duty liability.