(1) Any county, school district, improvement district, or municipality may refund any bonds issued under any statutory or constitutional authority at any time outstanding by the issuance of bonds bearing a rate or rates of interest that the issuer shall deem to be just and fair, whether or not greater than the rate or rates of interest borne by the bonds being refunded.
(2) No bonds shall be refunded at a rate of interest greater than the maximum rate set by the statutes or constitutional provision under which they were originally authorized.