AC Signal Interface (ACI) - The AC Signal Interface board monitors the voltages that are on the following nodes: input, filter and output. The board also monitors the currents that are on the input node and the output node. Contactor K1 and contactor K2 are controlled via two solid state relays that are located on the board.
Bypass Cabinet Controller (BCC) (Single Module System) - This is the controller for the static switch bypass option in a single-module system. The Bypass Cabinet Controller receives logic signals. The Bypass Cabinet Controller drives the gate signals of the bypass static switch.
Inverter Interface Board (SKI) - The Inverter Interface Board (SKI) provides the gate signals that are sent by the system controller to the inverter modules. Then, the Inverter Interface Board (SKI) sends a current feedback signal and a status signal from the inverter module to the system controller. Each inverter module in the system is connected to a Inverter Interface Board (SKI).
DC Interface (DCI) - The DC Interface board provides a feedback signal for the bus voltage to the controller.
Note: The DC Interface (DCI) also monitors the status of the fuses that are located between the capacitors and the DC common of the bus on models (UPS) that are prior to revision 2.4.
Dual 24 VDC Power Supplies - The dual 24 VDC power supplies are used to power all the circuit boards in the system.
EMI Filter (EMI) - The board filters the electronic noise from the lines for the three-phase AC. There is an EMI Filter (EMI) on the input terminals and there is an EMI Filter (EMI) on the output terminals.
Fan Monitor (FAN) - The Fan Monitor board monitors the status of the cooling fans. The cooling fans are located on the top of the system. Each fan has a status bit that is sent to the system controller.
Field Coil Driver (FCD) - The field coil driver board converts the signals from the system controller into isolated signals that are used by the field coil IGBTs. The field coil driver also provides current feedback of the top and bottom field coils.
Flywheel Interface (FWI) - For systems that are prior to 2.4 release, the flywheel interface board provides the current for the Hall effect sensors. The sensors are located on the inside of the flywheel. The sensors pass the flywheel's telemetry signals to the system controller. If the flywheel is equipped with a load cell, this board is the interface between the load cell and the system controller. This board is the interface between the following components and the System Controller on systems that are version 2.4 and later versions: Load Cell, Top Bearing, Temperatures, Temperatures (Field Coil), Armature Temperatures, Bottom Bearing Temperatures, Speed Sensing and Signals (Vibration).
Generator Set Start Controller (GSC) - This is the controller for the genset start option. The Generator Set Start Controller (GSC) provides the gate signal to the IGBTs for the Generator Set Start Module. Additionally, the Generator Set Start Controller (GSC)monitors the current for the IGBTs. The Generator Set Start Controller (GSC) communicates with the system controller.
Generator Set Start Driver (GSD) - This is the IGBT interface board for the genset start option. The Generator Set Start Driver (GSD) translates the logic level gating signals from the Generator Set Start Controller (GSC) into gate signals for the IGBT module. The Generator Set Start Driver (GSD) contains the various hardware for the Generator Set Start Controller (GSC) and the current sensing circuitry for the IGBT currents.
Parallel Cabinet Controller (PCC) (Multiple Module System) - This is the controller for the System Cabinet in a multi-module system. The Parallel Cabinet Controller monitors system voltages. The Parallel Cabinet Controller monitors system currents. The Parallel Cabinet Controller controls the bypass hardware. The Parallel Cabinet Controller communicates with all of the MMU cabinets. The Parallel Cabinet Controller processes user input signals and user output signals.
Parallel Cabinet Interface (PCI) - The Parallel Cabinet Interface (PCI) is located in the system cabinet. This board acts as a switch hub for RS232 connections, and Modem connections, that are for the MMU cabinets in the system. Modem lines and RS232 lines that are for each MMU cabinet in the system will be routed to the PCI. Rotary switches that are located on the PCI can then be used to select the MMU cabinet that will be accessed.
Parallel User Interface (PUI) - The Parallel User Interface (PUI) receives information concerning the status of the system cabinet and attached MMU cabinets from the Parallel Cabinet Controller. This information is displayed by using Light Emitting Diodes. This board reports the status of the keyswitch (system cabinet) and EPO switch to the Parallel Cabinet Controller. An audible alarm and a silence function are provided.
Note: The Parallel User Interface (PUI) is not used on systems that were manufactured with revision 2.4 or later.
Power Distribution (PWD) - The board distributes the power sources. The board contains the fuses for the power sources that are used throughout the system. The power sources that are distributed are the 24 VDC power supply, the 230 VAC for the input, and the 230 VAC for the output.
Rotor Position Sensor (RPS) - This board generates the rotor speed feedback that is used by the system controller in order to derive the gate signals for the flywheel inverter modules. The board also generates the signals that are used to monitor the levels of vibration in the flywheel.
Static Switch Interface (SSI) - The Static Switch Interface board converts the signals from the system controller into isolated signals that are used by the Silicon Controlled Rectifiers for the static switch.
System Controller - This controller is the brains of the system. All of the control signals for the inverters, field coil drivers, and the static switch originate from the controller. All of the status and the telemetry signals in the system are sent to the controller for monitoring.
System Input/Output Board - The board provides an isolation barrier between the controller and all of the communications ports that are used by the system. This is done in order to externally communicate to the system. This is done in order to internally communicate to the system. The following ports reside on the System Input/Output Board: Ethernet, COM RS-232/RS-485, Modem, UPS Net and CAN. These ports are used for internal control communications and external customer interface. In addition, there are 6 dry contact inputs and 6 dry contact outputs. The dry contact inputs utilize 24 VDC wetting voltage, which is supplied from the System Input/Output Board. The dry contact outputs are Form C style that provides a Normally Open contact and a Normally Closed contact. The last major function is the connection point for Remote Emergency Power Off. The System Input/Output Board has the ability to work with a Normally Open system or a Normally Closed Remote Emergency Power Off system. If no Remote Emergency Power Off is connected or the Normally Open circuit is used, a jumper must be installed on the Normally Closed circuit.
System Input/Output Daughter Board (SIOD) - The board provides an isolation barrier and a redundant barrier between the controller and all of the communications ports that are used by the system for internal communications to the system and external communications to the system. The following ports reside on the System Input/Output Daughter Board: COM RS-232/RS-485, UPS Net and Remote Panel. The COM RS-232/RS-485 port is a spare port that is unused and unsupported. The UPS Net is a redundant internal communication port that works with the UPS Net port on the System Input/Output Board. If a Remote Panel is installed on the system, the remote panel will be connected to this dedicated port.
User Interface (UIF) - The User Interface board provides system telemetry and data about the state of the system to the display panel. The display panel consists of the following components: LCD, 3 status lights, keyswitch and EPO switch. The board also sends signals about the status of the EPO switch and the keyswitch back to the system controller.
Zig Zag Controller (ZZC) - This board is used on four-wire systems. The board provides the stand-alone control for the proper switching of the neutral power conductor during entrance and exit of discharge. During normal operation, the output zigzag transformer is not connected to the utility neutral. When an outage is detected, the Zig Zag Controller Board will switch the neutral of the Zig Zag Transformer to the utility neutral for the duration of the discharge. The board contains the following components: 4 current channels, 3 high voltage AC ports, a dual SCR drive circuit, 4 isolated Form C outputs and 6 status inputs. The voltage and current ports will be used to detect a failure of the Zig Zag Transformer. If a need for discharge is detected, the Zig Zag Controller Board will turn on the gates of the SCR. In addition, the Zig Zag Controller Board will close an output in order to close the neutral contactor. The inputs are used for monitoring the status of contactor and breaker. Status bits and communications are transmitted by serial communication in order to communicate to the System Controller or the Parallel Cabinet Controller.
Satellite Boards - These boards are the boards that receive the control signals. The Satellite Boards also transmit status signals. The Satellite Boards are connected to the system controller via ribbon cable. Some of the boards serve as the signal feed to some other type of wiring. Most of the boards use the 24 VDC power supply in order to create ±15 volt supplies and ±5 volt supplies. The controller also generates 3.3 volts for the large scale integration devices.