A complete electrical upgrade to a stacker reclaimer was accomplished at a generating station in Missouri by Richmond Engineering Works. The machine was originally built in the 1970s and was mostly using original controls, however, spare parts were becoming more difficult to obtain. With the use of new, more reliable and easier troubleshooting PLC and motor drives, productivity increases. The operators receive better informational interface via PanelView™ Plus and equipment life is extended. This stacker reclaimer upgrade also provided increased personnel protection with the addition of arc flash rated equipment and an arc flash coordination study.
REW provided complete turnkey, material, installation and field services for the following:
• New Stainless Steel Electrical House. This was assembled in our shop and FAT tested prior to being shipped to the site. The North and East door egress are double doors, air lock type entry with three windows on outer vestibule so operator can stand in vestibules and use the newly installed remote control system to manually operate the machine from the gantry. To accomplish adding North and East vestibules, the original platform had to be extended for it infringed on the walkways of the original design. REW increased the platform and redesigned the walkways. E-House air pressurized via air intake above tripper and filtered with Caterpillar® style filtering.
• New PLC ControlLogix L72 Control System.
• PowerFlex® Swing DC Drives.
• PowerFlex® Bucket Wheel DC Drive.
• PowerFlex® Hopper Feeder VFD Drive.
• PowerFlex® Travel Drive VFD Drives – Travel motors will be utilized in the deceleration of the stacker reclaimer rather than the old system of relying solely on brakes. They are engineered to allow dynamic load sharing among the four travel drives.
All drives are housed in a NEMA12 with a flange operated molded case circuit breaker for local disconnect or isolation. Door mounted keypads allow programming and monitoring without opening cabinet.
• New Arc Resistant Motor Control Center (MCC).
• 500 KVA Power Distribution Transformer Mounted Inside Electrical House.
• 480 VAC Switch Gear with Arc Flash Protection All the Way to 86.9 KV Switch Gear.
• Festoon – Upgraded with new cable tray, trolley equipment and cable. The cable tray under the elevating conveyor was repositioned to allow for more travel of the festoon system.
• VFD Rated Travel Motors, AC Thruster, Brakes and Couplings.
• Outside LED Lighting and Receptacles.
• Dynapar Encoder for Boom Hoist, Boom Swing and Splitter Gate Positions.
• Electro-Sensor Shaft Speed Sensors for Boom Conveyor, Yard Conveyor and Bucket Wheel.
• Thermo Scientific Ramsey Mercury-Free Tilt Sensors for Boom Tip Stacking, Hopper and Plug Chute Probes.
• Thermo Scientific Ramsey Protection Switches for Pullcords and Belt Alignment Switches.
• Eaton (Cutler Hammer) Crane Control Limit Switches.
• Texas Electronics Anemometer.
• Edwards Signaling Horns Boom and Yard Conveyors and Stacker Reclaimer Travel.
• Allen Bradley Push Buttons and Emergency Stop Operators – Existing pushbuttons and emergency stop buttons around the stacker reclaimer were replaced and the new ones are now housed in a stainless steel enclosure.
• Fiber Optic Communications to Coal Yard PLC, Arc Flash Protection for 6.9 KV Supply and Fail Safe 10 mS Tripping of Yard Belt Via Pullcords on Stacker Reclaimer.
No job is without challenges and this one is no exception. Due to the electrical house having to be placed under the tripper, REW had to design and build a temporary structure with rollers to sit the new electrical house on and slide the new electrical house under the tripper and into place.
If your stacker reclaimer is aging and in need of an upgrade, for more information contact REW at 412-787-9640.