IMPELLER 1310057 - Caterpillar

Cabinet Description
The Series 1200 UPS is a flywheel-based, two-terminal DC energy storage system. The Series 1200 UPS receives recharge and float power from the two-terminal UPS DC bus. The Series 1200 UPS returns power to the same DC bus whenever the UPS is in discharge. The Series 1200 UPS flywheel cabinet has both AC and DC voltage input sources.The flywheel cabinets are 1067 mm (42 inch) wide cabinets. The flywheel cabinets are located at the right of the UPS system. The flywheel cabinets contain the flywheels and associated electronics. Each flywheel cabinet contains two flywheels. Each flywheel supplies 240 kW. A minimum of two flywheel cabinets are required in the base Series 1200 unit and two additional flywheel units can be added for extended run time.DC power enters and exits the top of the flywheel cabinet through the "DC Bus Wireway". The "DC Bus Wireway" is connected between the flywheel cabinet and the inverter cabinet. DC power flows through the "DC Bus Disconnect Switch" and the DC bus fuses to the "Flywheel Inverter" assemblies and "Field Coil Driver PWA".The flywheel interface assemblies convert the DC voltage to variable frequency AC voltage. The variable frequency AC voltage is used for the flywheels. The field coil drivers control the DC current in the upper and lower field coils.During discharge, the flywheel inverters release AC current to the flywheel inverter assemblies which convert the flywheel EMF to DC in order to keep the DC Bus charged to operational voltages.Front Door Components
The front door of the flywheel cabinet has a key switch, an Emergency Module Off (EMO) button and houses two air filters. The EMO button will shut down all power to the flywheel inverters and field coil drivers. The keyswitch controls operation of the flywheel cabinet.Shield Components
Behind the front doors are a number of protective shields and another set of controls. There are four removable shields. There is a fifth swing out panel that contains the APC board. The APC board provides a centralized location for the flywheel digital control. The APC board provides the hardware platform needed in order to support system control algorithms. Also, the APC board provides the hardware platform needed in order to support program execution, storage, and acts as a communications port in order to allow interface with other system PWAs.Above the APC board inside of the cabinet, there is an RS-232 serial port that connects to the "Dual Network Interface PWA" (DNI). The RS-232 serial port is also used in order to connect UPS View to the flywheel cabinet for service calibration.The DC disconnect switch is a manual switch that isolates the UPS DC bus from the flywheel cabinet. The switch handle that is located on the front of the shield controls the switch that is in the back of the cabinet. The UPS should be placed in "Bypass" before opening or closing the DC disconnect switch. The DC disconnect switch should only be operated when the green indicator is on.In the center of the