(a) The following advances relate back to the time of the recording of the mortgage, and are prior and superior to subsequent encumbrances and conveyances:

(1) All advances, whether obligatory or optional, made under an open-end mortgage in accordance with this chapter;

(2) All obligatory advances made under any mortgage securing a revolving credit agreement that is not an open-end credit agreement and under any obligatory or optional extension, renewal or amendment of such revolving credit agreement; provided, that no optional extension, renewal or amendment shall increase the advances entitled to priority under this subdivision (a)(2) above the maximum amount entitled to priority under the original revolving credit agreement; and

(3) All obligatory advances made under any other mortgage securing future advances.

(b) All obligatory advances made pursuant to an optional increase in the credit limit of a revolving credit agreement that is not an open-end credit agreement and pursuant to any obligatory or optional extension, renewal or amendment of such increase shall relate back to the time of the recording of the mortgage securing such revolving credit agreement and are prior and superior to subsequent encumbrances and conveyances unless the mortgagee has actual notice of an intervening conveyance or encumbrance prior to increasing the credit limit. If the mortgagee has actual notice of an intervening conveyance or encumbrance prior to increasing the credit limit, all such obligatory advances shall relate back to the time of the increase. For the purpose of this subsection (b), “actual notice” means knowledge in fact from any source by any means.

(c) Optional advances made under any mortgage securing future advances, other than an open-end mortgage, are superior in priority to any intervening conveyance or encumbrance unless the mortgagee has actual notice of the intervening conveyance or encumbrance prior to exercising the mortgagee's option to make the advance. For the purpose of this subsection (c), “actual notice” means knowledge in fact from any source by any means.