[Code of Federal Regulations] [Title 49, Volume 4] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 49CFR236.109] [Page 549] TITLE 49--TRANSPORTATION CHAPTER II--FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 236_RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, Subpart A_Rules and Instructions: All Systems Sec. 236.109 Time releases, timing relays and timing devices. Time releases, timing relays and timing devices shall be tested at least once every twelve months. The timing shall be maintained at not less than 90 percent of the predetermined time interval, which shall be shown on the plans or marked on the time release, timing relay, or timing device. [49 FR 3384, Jan. 26, 1984]