the arbitrator is appointed, no new or different claim may be submitted except with the consent of the arbitrator and all other parties.” The Court has held also that an arbitrator acts in an excess of his or her authority under the third point of narrow certiorari review if in fashioning a remedy the arbitrator mandates that an illegal act be carried out or grants an award that addresses issues beyond the scope of the collective bargaining agreement or that extends beyond the terms and conditions of the employment. Township of Ridley v. Fraternal Order of Police Lodge No. 27, 718 A.2d 872 (Pa.Cmwlth. 1998); Town of McCandless v. McCandless Police Officers Ass’n, 677 A.2d 879 (Pa. Cmwlth.1996). See also Appeal of Upper Providence Police Delaware County, 514 Pa. 501, 526 A.2d 315 (1987) (<HOLDING>); Washington Arbitration Case, 436 Pa. 168, 269
holding that arbitrators award will be vacated if    mistaken as to applicable law holding that an award may be in excess of the arbitrators powers if it requires the public employer to perform an act that is prohibited by law or if it does not involve legitimate terms and conditions of employment holding that an award of arbitration cannot be set aside for mere errors of judgment either as to the law or the facts if the award is within the scope of the submission and the arbitrators are not guilty  of the acts of misconduct set forth in the statute the award operates as a final and conclusive judgment and  however disappointing it may be  the parties must abide by it holding that it may not holding that a court reviewing an arbitrators award in an act 111 grievance arbitration involves questions regarding 1 the jurisdiction of the arbitrator 2 the regularity of the proceedings 3 an excess of the arbitrators powers and 4 deprivation of constitutional rights