2121b1b5_re___AccountingExplanation_com__Reasons
[0] Repair and maintenance A/c is debited. [Sr. No.] (xv) [Nature of Expenditure] Revenue Expenditure. [Reasons] 
A worn out part of the machinery is simply the cost of repair and maintenance of fixed asset. The value and profit earning capacity of the machinery has not increased in any way, so it is a revenue expenditure.
Difference between Capital Expenditure and Revenue Expenditure - AccountingExplanation.com
Reasons