Section 75.352 - Actions in response to AMS malfunction, alert, or alarm signals(a) When a malfunction, alert, or alarm signal is received at the designated surface location, the sensor(s) that are activated must be identified and the AMS operator must promptly notify appropriate personnel.(b) Upon notification of a malfunction, alert, or alarm signal, appropriate personnel must promptly initiate an investigation to determine the cause of the signal and take the required actions set forth in paragraphs (c), (d), or (e) of this section.(c) If any sensor installed in accordance with §§ 75.340(a)(1)(ii) , 75.340(a)(2)(ii) , 75.350(b) , or 75.350(d) indicates an alarm or if any two consecutive sensors indicate alert at the same time, the following procedures must be followed unless the cause of the signal(s) is known not to be a hazard to miners: (1) Appropriate personnel must notify miners in affected working sections, in affected areas where mechanized mining equipment is being installed or removed, and at other locations specified in the § 75.1502 approved mine emergency evacuation and firefighting program of instruction; and(2) All personnel in the affected areas, unless assigned other duties under § 75.1502 , must be withdrawn promptly to a safe location identified in the mine emergency evacuation and firefighting program of instruction.(d) If there is an alert or alarm signal from a methane sensor installed in accordance with §§ 75.323(d)(1)(ii) and 75.362(f) , an investigation must be initiated to determine the cause of the signal, and the actions required under § 75.323 must be taken.(e) If any fire detection components of the AMS malfunction or are inoperative, immediate action must be taken to return the system to proper operation. While the AMS component repairs are being made, operation of the belt may continue if the following conditions are met: (1) If one AMS sensor malfunctions or becomes inoperative, a trained person must continuously monitor for carbon monoxide or smoke at the inoperative sensor.(2) If two or more adjacent AMS sensors malfunction or become inoperative, a trained person(s) must patrol and continuously monitor for carbon monoxide or smoke so that the affected areas will be traveled each hour in their entirety, or a trained person must be stationed to monitor at each inoperative sensor.(3) If the complete AMS malfunctions or becomes inoperative, trained persons must patrol and continuously monitor for carbon monoxide or smoke so that the affected areas will be traveled each hour in their entirety.(4) The trained person(s) monitoring under this section must, at a minimum, have two-way voice communication capabilities with the AMS operator at intervals not to exceed 2,000 feet and report contaminant levels to the AMS operator at intervals not to exceed 60 minutes.(5) The trained person(s) monitoring under this section must report immediately to the AMS operator any concentration of the contaminant that reaches either the alert or alarm level specified in § 75.351(i) , or the alternate alert and alarm levels specified in paragraph (e)(7) of this section, unless the source of the contaminant is known not to present a hazard.(6) Detectors used to monitor under this section must have a level of detectability equal to that required of the sensors in § 75.351(l) .(7) For those AMSs using sensors other than carbon monoxide sensors, an alternate detector and the alert and alarm levels associated with that detector must be specified in the approved mine ventilation plan.(f) If the minimum air velocity is not maintained when required under § 75.350(b)(7) , immediate action must be taken to return the ventilation system to proper operation. While the ventilation system is being corrected, operation of the belt may continue only while a trained person(s) patrols and continuously monitors for carbon monoxide or smoke as set forth in §§ 75.352(e)(3) through (7) , so that the affected areas will be traveled each hour in their entirety.(g) The AMS shall automatically provide both a visual and audible signal in the belt entry at the point-feed regulator location, at affected sections, and at the designated surface location when carbon monoxide concentrations reach:(1) The alert level at both point-feed intake monitoring sensors; or(2) The alarm level at either point-feed intake monitoring sensor. 69 FR 17529 , Apr. 2, 2004, as amended at 73 FR 80613 , Dec. 31, 2008