Warning - GE ALPS Instruction Manual

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
CAUTION
isolating shoes are conducive to the generation of electrostatic discharge currents. Care should be exer-
cised 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
standoffs 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. Fail-
ure 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 ALPS 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. See
Figure 3–5: INPUT BOARD DIAGRAM on page 3–7 for a block diagram of the input board.
3-6 ALPS Advanced 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