Oregon Revised Statutes Justice Courts § 51.300

(1) At the request of the justice of the peace of the justice court;

(2) In the event of a vacancy in the office of the justice of the peace, until the vacancy is filled as provided by law; or

(3) In the event of the absence, incapacity or disqualification of the justice of the peace, during the period of such absence, incapacity or disqualification.