It is given in Taxmann's Direct Taxes Ready Recnor in Para 49.3 in that 49.3-2 in Scope of Sec 40A(3) that the section is applicable even if depriciable asset is purchased.
Reckoner is only v.k. singhania's interpretation of the income tax act.Please read the bare act.It does not say anythng about applicability of sec 40A(3) to depreciation.