4 minute read
CONTROLS IN THE MACHINERY HOUSE
CONTROLS IN THE MACHINERY HOUSE
Located on the front of the Motor Control Center and the High Voltage Cabinets are the controls used by the operator for the start-up and/or shutdown of this machine. A description of these controls is given here and their use is detailed in the Machine Start Up and Complete Shutdown procedures following.
Items on the Motor Control Center
1. OPERATOR'S CAB AIR CONDITIONER
2. WELD RECEPTACLE
3. FIELD EXCITATION TRANSFORMER
4. PHASE SEQUENCE - This panel includes a red light which indicates an error in the power supply when illuminated. Electrical interlocks will prevent machine start-up if phase reversal exists.
Also included on this panel is a voltmeter and a 4-position switch to check the voltage across each phase: OFF, L1-L2, L2-L3 and L1-L3.
5. AUXILIARY BUS MAIN BREAKER CB-AB
6. FILTER FAN #1 - Includes a green light which indicates the fans are operating plus start-stop pushbuttons.
7. FILTER FAN #2 - Includes a green light which indicates the fans are operating plus start-stop pushbuttons.
8. HOIST MOTOR BLOWER - This panel includes START and STOP pushbutton for operating the air cooling fan on the DC drive motor. The green indicating light above the pushbuttons indicates that the hoist blower circuit is energized.
Motor Control Center Layout (Front View)
9. AIR COMPRESSOR - This panel includes a two position selector switch which controls the operation of the air compressor. The AUTO position lets the compressor cycle on and off automatically a dictated by its pressure switch. The OFF position makes air compressor is running. The compressor will not operate if phase in incoming power supply is reversed.
10. ANTI-CONDENSATION HEATERS - This panel includes a two position selector switch which controls the operation of the space heaters in the motor control center, the DC Cabinet, the dig-propel cabinet, all the DC drive motors, and the M.G. Set. AUTO position automatically energizes the heaters whenever the M.G. Set is shut down. OFF position turns the heaters off. The green light above the selector switch illuminates whenever the heaters are energized. These heaters are not thermostatically controlled. Once energized, they operate continuously until shut off or the M.G. Set is started. These heaters should be used only during periods of high humidity or low temperatures.
11. HOIST CABLE WINCH
12. CPE TRANSFORMER - Control Power Excitation Transformer breaker.
13. CROWD & SWING MOTOR BLOWERS - This panel contains a green indicating light that indicates the crowd and swing motor blowers circuits are both energized.
14. PROPEL MOTOR BLOWERS - This panel includes a green indicating light that indicates the propel motor blowers circuit is energized. These blowers operate only when the machine drive is in the propel mode.
NOTE: The following breakers on the Motor Control Center must be closed for machine startup and operation:
• Phase Sequence.
• Incoming Line.
• Filter Fans Nos. 1 and 2.
• Hoist, Crowd & Swing, and Propel Motor Blowers.
• Field Excitor Transformer.
• Air Compressor.
• Regulator Power Supply.
HIGH VOLTAGE CABINET
The cabinet includes:
• Startup Panel
• Main Disconnect Switch
• Vacuum Contactor Cabinet
1. POWER FACTOR METER indicates the MG set drive motor power factor.
2. HOUR METER - an elapsed time meter that shows total machine operating hours with excitation (L.E.) On.
3. AMMETER - (0-200 Amp Range) Indicates the drive motor current in amperes.
4. HIGH VOLTAGE CABINET - VOLT METER (0-8250 Volt Range) - an A.C. voltmeter that indicates the voltage on the incoming trail cable.
5. MULTILIN 269+ PROTECTIVE RELAY MODULE - Monitors the dive motor to protect against over current, overload, phase unbalance and ground fault.
High Voltage Cabinet (Front View)
6. GROUND MONITOR TRIP - A red pushbutton used by qualified electrical maintenance personnel to check the ground trip circuit in the mine substation and power supply. Pressing this button will cause the power supply to the machine to be turned off (de-energized). It must be reset and reenergized at the mine substation.
7. BLOWN FUSE INDICATOR (BFI) - Indicates a blown fuse on the secondary of the high voltage disconnect switch.
DANGER! ALWAYS OPEN THE DISCONNECT SWITCH BEFORE REPLACING A FUSE.
8. BFI RESET - A black pushbutton used to reset the visual blown fuse indicator after replacement/ correction. Press this button once to verify a fuse fault before notifying electrical maintenance personnel.
9. M.G. SET START - A green illuminated pushbutton for starting the M.G. Set. When starting M.G. Set, press and hold this button until M.G. Set is up to its normal operating speed. The green light in this button being on indicates the M.G. Set is running.
10 M.G. SET STOP - A red pushbutton that, when pressed, de-energizes (shuts down) the M.G. Set induction drive motor. The M.G. Set will coast to a stop.
CAUTION: STARTING THE M.G. SET REPEATEDLY OVER 3 OR 4 TIMES IN ONE HOUR COULD CAUSE PERMANENT DAMAGE.
11. M.G. SET MOTOR DISCONNECT SWITCH - Disconnects power to the M.G. set drive motor.
