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3.3 PRINTED CIRCUIT BOARD MODULES
3.3 PRINTED CIRCUIT BOARD MODULES
This relay contains electronic components that can be damaged by electrostatic discharge
currents. The main source of electrostatic discharge currents is the human body, and low
humidity, carpeted floors, and isolating shoes are conducive to the generation of electrostatic
CAUTION
discharge currents. Care should be exercised when removing and handling the modules.
Each person handling the printed circuit boards must ensure that their body through a
grounding wrist strap or similar apparatus tied to ground potential before touching any of the
components on the boards or the boards themselves.
The printed-circuit boards are located inside the case in the positions shown in Figure 3–3: CIRCUIT BOARD
LOCATIONS on page 3–3.
3
Each module consists of a printed-circuit board and aluminum plate. The printed circuit board is securely
mounted to five stand-offs on the plate with five screws. There are two tabs on the front of the aluminum plate
for removing and inserting the module. Electrical connection is made by an edge connector on the rear of the
input and output boards and ribbon cables and the bus card connector on the front of the boards.
Each module is identified by silk screen description on the printed circuit board.
Power down the relay by removing any DC voltage to the relay before removing or inserting
modules. Failure to do so can permanently damage the relay.
CAUTION
The Keypad / Display Interface contains a 4-line, 20-character LED display, a green/red status LED, a red trip
LED, a 9-pin RS232 port, and the 20-character keypad. The interface logic is contained on two printed circuit
boards (DSP/ANI and LUI).
•
LUI module board contains all of the items listed above except the keyboard decoding logic which is on the
DSP/ANI board.
•
The Output board contains the LPS-D communications interface (RS232 / ASCII), a Critical Alarm Timer,
various output relay drivers, and user-selectable switches to enable remote functions.
The input board contains the input logic which includes the programmable contact converter optocouplers. The
SCADA I/V (current/voltage) selection switch, SW1, is in the back, left corner on this board. The IRIG-B input is
also on this board. Figure 3–5: INPUT BOARD DIAGRAM is the block diagram of the input board.
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LPS-D Line Protection System
3 HARDWARE DESCRIPTION
3.3.1 WARNING
3.3.2 BASIC CONSTRUCTION
3.3.3 MODULE IDENTIFICATION
3.3.4 LOCAL USER INTERFACE (LUI)
3.3.5 INPUT BOARD
GE Power Management
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