Petition for Modification
In the matter ofRivers Edge Mining Inc.
Rivers Edge Mine
I.D. No. 46-08890
Docket No. M-2002-042-C
30 CFR 75.900
- The nominal voltage of the power circuit(s) shall not exceed 995 volts.
- The nominal voltage of the control circuit(s) and audible alarms units shall not exceed 120 volts.
- Vacuum contactors shall be built into or permanently affixed to the transformer enclosure and properly separated and isolated from the other components of the unit.
- Vacuum contactors with associated protective relays shall provide undervoltage protection for low and medium-voltage circuits serving three-phase alternating current equipment.
- The voltage rating of the vacuum contactor(s) shall be
at least the maximum rms voltage of the circuit being
protected. The continuous current rating of the vacuum
contactor(s) shall be at least the full load current of
the utilization equipment.
- Each circuit breaker installed in conjunction with a
contactor shall be equipped with devices to provide
short-circuit protection for each piece of equipment.
In addition, the design of each installation must
ensure coordination of the circuit breaker and vacuum
contactor so that the circuit breaker always opens
first when a short-circuit occurs.
- Ground-fault, overload and short-circuit conditions shall preclude closing the contactor until the molded case breaker is reclosed manually or the overload and ground-fault relays are reset manually.
- The fail-safe ground check circuit shall cause the
contactor to open when either the ground or pilot wire
is broken.
- A monthly exam will be conducted on each circuit to assure proper operation of the vacuum contactor. The monthly exam shall include activating undervoltage, grounded phase and ground monitor trip devices to test proper operation. The results of the tests of the vacuum contactors shall be recorded with the required monthly tests of the circuit breakers.
- Prior to each remote start-up, an audible alarm at each affected vacuum contactor or affected area, shall be activated for approximately 15 seconds. Circuits shall be wired so that vacuum contactors can only be closed remotely when undervoltage or loss of voltage condition no longer exists. All other conditions that cause the vacuum contactor to trip shall require a manual reset at the vacuum contactor. Circuits providing power to portable or mobile equipment shall not be designed to be remotely reset.
- 11. The Petitioner's alternative method shall not be implemented until all qualified persons who perform work on the equipment and circuits have received training in safe maintenance procedures, and the terms and conditions of the Proposed Decision and Order.
- Within 60 days after this Petition for Modification is granted, the Petitioner shall submit proposed revisions for its approved 30 CFR Part 48 training plan to the Coal Mine Safety and Health District Manager for the area in which the mine is located. These proposed revisions shall specify task training for all miners who are assigned to work in the area. The training shall include the following elements: (a) The purpose of the prestart alarm systems, and vacuum contactor systems; (b) The potential hazards of working on or near belt conveyors and belt conveyor drives; and (c) The requirements of 30 CFR 75.1725(c)and (d). The procedures of 30 CFR 48.3 for approval of proposed revisions to already approved training plans shall apply.
_________________________________
Allyn C. Davis
Acting Deputy Administrator
for Coal Mine Safety and Health
