EXHIBIT 4.189

                            CERTIFICATE OF FORMATION

                                       OF

                           PEC EQUIPMENT COMPANY, LLC

         1. The name of the limited liability company is PEC Equipment Company,
LLC.

         2. The address of its registered office in the State of Delaware is
Corporation Trust Center, 1209 Orange Street, in the City of Wilmington, County
of New Castle. The name of its registered agent at such address is The
Corporation Trust Company.

         3. This Certificate of formation shall be effective on September 8,
2003.

         IN WITNESS WHEREOF, the undersigned have executed this Certificate of
Formation of PEC Equipment Company, LLC this 8th day of September, 2003.

                                              /S/ JOSEPH W. BEAN
                                              ---------------------------------
                                              Joseph W. Bean, Esquire