Account key and Accural G/L account

Hi,

For a freight condition we have assigned FRE as the account key and FR1 as the accrual. For the both the keys we have assigned GL accounts.

FRE -506000 ACCT KEY

FR1 131100 ACCRUAL

Postings:

1) AFTER GRN - The accural key gets hit

243000 Material

131100 GR/IR

2) INVOICE also the accural key gets hit

131114 Vendor account

131100 GR/IR

When and in which scenario will the account key get hit?

Secondly, are there any setting required to make sure that the account key GL (506000) gets hit.

Regards,

mahesh.