§ 236.309 Loss of shunt protection; where required.
(a) A loss of shunt of 5 seconds or less shall not permit an established route to be changed at an automatic interlocking.
(b) A loss of shunt of 5 seconds or less shall not permit the release of the route locking circuit of each power-operated switch hereafter installed.
[49 FR 3385, Jan. 26, 1984]