(1) An overdraft existing for 90 days shall be charged off to the profit and loss account of the savings bank at the expiration of that time.

  (2) A director or executive officer of a savings bank shall not knowingly overdraw his or her account.

  (3) Unless a debt constitutes a claim against a solvent estate in probate, if the interest on a debt held by a savings bank is past due and unpaid for a period of 12 months, the savings bank shall charge off to its allowance for loan and lease losses the portion of the debt that is not well secured.