Version 1 Hardware
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| Illustration 1 | g01326534 |
4-Wire Transformer Cabinet Fan Plenum Panel - Version 1 (1) General Purpose Interface Board (2) External Source Sync Board (ESS) (3) 4-Wire Thermal Switch Monitor Board (TSM) (4) Fuses F96, F97 (5) Secondary Current Transformers (CTs) (6) Fuses F58-F60 (ESS) F61-F63 (7) Fuses F73-F76, F94, F95 | |
The General Purpose Interface Board (1) in the 4-Wire Transformer cabinet is located on the fan plenum shield. The fan plenum shield is above the fans in the middle of the cabinet.
Version 2 Hardware
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| Illustration 2 | g01326623 |
4-Wire Transformer Cabinet Upper Panel - Version 2 Hardware (1) General Purpose Interface Board (2) External Source Sync Board (ESS) (3) 4-Wire Thermal Switch Monitor Board (TSM) (4) Fuses F96, F97 (5) Secondary Current Transformers (CTs) (8) Fuses F61-F63 F103 (9) Fuses F73-F76, F94, F95, F104,105 (10) Fuses F64-F66 | |
The General Purpose Interface Board (1) in the 4-Wire Transformer cabinet is located on the top component panel.
Multidrop Bus
The General Purpose Interface Board (1) provides serial data over the Multidrop Bus. The General Purpose Interface Board (1) functions as a slave on this bus. receiving commands from the APC-2 and responding with status information.
The General Purpose Interface Board (1) has a jumper-selectable 100-Ohm terminating resistor for the Multidrop bus. Jumper JMP9 provides terminal resistance. There is also a switch that sets the Node ID. Set the GPI Board Node ID and terminating resistor jumper to the settings on the following table.
| Node ID | 8 | |
| Terminating Resistor | JMP9 | |
| Version 1 Hardware | Always installed if 4-Wire Option present | |
| Version 2 Hardware | Never installed | |
Refer to the information in the Systems Operation, Testing and Adjusting, "Multidrop Network - Setup" for information on setting up the Multidrop Network.
Fan Tachometers
The General Purpose Interface Board (1) provides circuitry to read magnetic tachometer signals for the three fans in the 4-Wire Transformer Cabinet. Sensors in each fan provide once-per-revolution digital pulses to the General Purpose Interface Board (1). These pulses are digitized by the General Purpose Interface Board (1) and relayed to the APC-2 in the Controls Cabinet.
Temperature Measurement
The General Purpose Interface Board (1) provides the system with temperature measurements from an on-board thermistor (R37) and three remotely located high temperature thermistors. The on-board thermistor measures the temperature near the General Purpose Interface Board (1). The three remotely located high temperature thermistors measure the temperature of the 4-Wire Transformer at the bottom rear of the cabinet. The General Purpose Interface Board (1) digitizes temperature information and makes the data available to the APC-2.
General Purpose Inputs
The General Purpose Inputs on the General Purpose Interface Board (1) in the 4-Wire Transformer Cabinet are not used.
Removal
| NOTICE |
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Electrostatic discharge can damage integrated circuits or semiconductors if you touch bus connector pins. When not in use, keep the module in the static-shield bag. Follow these guidelines when you handle any module: Touch a grounded object to discharge static potential. Wear an approved wrist-strap grounding device. Do not touch the bus connector or connector pins. Do not touch circuit components inside the module. If available, use a static-safe work station. |
- Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (4 Wire Transformer Cabinet)" in order to de-energize the system and gain access to internal components.
- Disconnect all connectors from the board. The connectors locations in the unit are labeled. Verify each connector to make sure that the label is present and legible.
Refer to Illustration 3.
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| Illustration 3 | g01327217 |
(11) On-board Thermistor (12) Node ID SW1 (13) Multidrop J1A (14) Terminal Resistor JMP9 | |
- Unscrew the cross tip grounding screw from the Board.
- Disconnect the seven white plastic stand-offs connecting the board to the right panel using the following method.
The board must be removed from the stand-offs without bending the board.
- Pinch the head of each stand-off so that the board is not locked to the stand-off but is still attached to the stand-off.
- Remove the board by gently and evenly pulling the board from all stand-offs at the same time.
Installation
| NOTICE |
|---|
Electrostatic discharge can damage integrated circuits or semiconductors if you touch bus connector pins. When not in use, keep the module in the static-shield bag. Follow these guidelines when you handle any module: Touch a grounded object to discharge static potential. Wear an approved wrist-strap grounding device. Do not touch the bus connector or connector pins. Do not touch circuit components inside the module. If available, use a static-safe work station. |
Always practice Electrostatic Discharge (ESD) prevention by using a static strap when handling electronic boards.
- Position the board in the cabinet over the seven white stand-offs that are connected to the right panel.
- Push the board, gently and evenly, onto all the stand-offs simultaneously. Make sure all stand-offs are locked in place.
- Insert the cross tip ground screw into the fan plenum shield. Tighten the screw.
- Plug the wire connectors into the correct connectors on the board. Check the labels on each connector for proper placement.
Refer to Illustration 3.