Interfaced Supplier Invoice to PA and accounting?

Dear Experts,

I have created Supplier invoice in payable and interfaced to projects and run Generate Cost Accounting Events program. I have checked accounting in PA at Expenditure enquire form, I found only debit account generated and no credit account generated?  Is it standard functionality? In which Scenarios Credit account will be generate? I am able to see Debit and Credit account GL entries in Expenditure enquire form?Which accounting entries transfer to GL? Could you please explain accounting in PA for interfaced supplier invoices? Thanks in advance.

Thanks,

Vikram.