[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR236.106] [Page 509] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 236--RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES--Table of Contents Subpart A--Rules and Instructions: All Systems Sec. 236.106 Relays. Each relay, the functioning of which affects the safety of train operations, shall be tested at least once every four years except: (a) Alternating current centrifugal type relay shall be tested at least once every 12 months; (b) Alternating current vane type relay and direct current polar type relay shall be tested at least once every 2 years; and (c) Relay with soft iron magnetic structure shall be tested at least once every 2 years. [49 FR 3384, Jan. 26, 1984]