42 Pa. C.S. § 4524
Except as otherwise provided in section 4525 (relating to equipment used for selection of jurors), the jury selection commission shall maintain a master list or jury wheel and shall place therein the names of persons included on the list of qualified jurors. Upon receipt of a court order pursuant to section 4531 (relating to issuance of court orders for jurors), the commission shall publicly select at random from the master list or jury wheel such number of names of persons as may be required to be summoned for assignment to jury arrays. A separate list of names and addresses of persons assigned to each jury array shall be prepared and made available for public inspection at the offices of the commission no later than 30 days prior to the first date on which the array is to serve.
42 Pa.C.S. § 4524