Annual Report,2009 - Directorate General of Mines Safety

DGMS Annual Report, 2009
(i)
(ii)
(iii)
(iv)
The deviation of the measured gas concentration shall not be
more than 3% for all sensor types when tested with standard
gases.
The maximum interval of calibration of sensors shall not
exceed three months, alternating between the OEM and the
users. However, The OEM shall examine the complete
telemonitoring system in totally at least once every six months.
Adequate samples of standard gases shall be always made
available at the concerned mine.
Proper records of calibrations done, duly singed by the
designated officer and the Manager for the purpose, shall be
maintained at the mine.
4.0 Use of the approved system in the mines :- Any sale/purchase of the
continuous telemonitoring system shall be in conformity with the approved
system in respect of all the basic components as mentioned above.
5.0 The minimum required power back up with the telemonitoring system:- The
minimum required power backup in the event of disruption of the main
electrical power supply shall be for a period of four hours.
6.0 Alarm system in the telemonitoring system :- The minimum intensity of the
audio part of the audio-visual alarm provided with the telemonitoring system
shall be 90 dB(A). In the underground workings, at least one audio alarm shall
be provided with every out-station of the telemonitoring system.
7.0 Electrical interlocking of the telemonitoring system :- The tripping circuit of
the telemonitoring system shall be electrically interlocked with the power
supply system of the connected workings so as to cut off power supply when
the concentration of inflammable gases measured exceeds a preset value.
8.0 Recording of telemonitoring events on surface :- Every telemonitoring
installation shall be provided with an arrangements for recording and
retrieving data on a continuous basis.
9.0 Maintenance of the telemonitoring system :- Every telemonitoring system
shall be associated with a comprehensive Annual Maintenance Contract
(AMC) with the OEM to cover both for spares and services. The period of
AMC shall be not less than 5 years. The maximum response time for attending
to any maintenance related problems shall not be more than 24 hours.
It is therefore, requested that the above mutually agreed recommendations are
implemented strictly in respect of all telemonitoring system installed in underground
coal mines. For ensuring efficient working of such systems on a long-term basic, the
ISO shall have suitable time bound action plans and shall rigorously follow-up with
the same.
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