30 CFR § 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
(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 § §
(b), or 75.350
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 §
approved mine emergency evacuation and firefighting program of
(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, must be withdrawn promptly to a safe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
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 §
(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 §
(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
(f) If the minimum air velocity is not maintained when required
under Sec. 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 Sec. Sec. 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;
(2) The alarm level at either point-feed intake monitoring sensor.