Illustration 1 | g01277605 |
Location of the Static Switch (1) Static Switch Assembly |
Illustration 2 | g01277585 |
Static Switch Assembly (2) Heat Shrink and Shroud (3) Snubber Assembly (3) (4) Static Switch Interface Board (5) Static Switch Module (3) |
The Static Switch assembly (1) is composed of three thyristor modules. One module is connected to each of the input phases. Each module has two devices. In the system, the devices are connected in parallel. However, the devices are connected in opposite directions. The following functions are functions of the static switch:
- Isolation of the input node during a discharge
- Synchronization of the signals of the inverter node to the signals of the input node upon restoration of the input signals after an outage
- Initial charge of the DC bus
Only one of the parallel thyristors is turned on at a time. The thyristors only conduct current when the thyristors are forward biased. The preceding statement applies to all three of the phases.
Refer to Systems Operation, Testing and Adjusting, RENR9988, "Internal Component Preremoval Steps (Flywheel Cabinet)" in order to shut down the system and gain access to internal components.
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 a 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. |
- Remove the tie-wraps that are located at the back of the static switch assembly (1). The tie-wraps are the tie-wraps that hold the following connectors to the Static Switch Interface Board (4): "J1", "J7" and "J9".
- Disconnect all connectors from the Static Switch Interface Board (4). There are six connectors on the front installed side of the board (4). There are three connectors on the back installed side of the board (4). Verify each label for each connector for subsequent installation.
- Remove the Static Switch Interface Board (4) from the Static Switch assembly (1). Remove the four screws that hold the Static Switch Interface Board (4) to the four standoffs connected to the shroud for the heat shrink.
Note: Store the Static Switch Interface Board (4) in an anti-static bag.
- Remove the cable from the front of each of the three Static Switch Modules (5). Remove the cable from the back of each of the three Static Switch Modules (5).
- Remove the right front bolt that holds the assembly (1) to the top of the cabinet for the flywheel.
- Loosen the left front bolts and rear bolts that hold the assembly (1) to the top of the cabinet for the flywheel.
- Slide the assembly (1) to the left. Slide the assembly off the loosened bolts in order to remove the assembly (1) from the cabinet.
Illustration 3 | g01277683 |
Static Switch Interface Board |
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 a 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. |
- Install the assembly (1) in the cabinet for the flywheel.
- Install the static switch interface board (4) in the static switch assembly (1). Use the four screws that hold the assembly (1) to the four standoffs connected to the shroud for the heat shrink.
- Connect six connectors on the front side of the Static Switch Interface Board (4). Connect the three connectors on the back side of the Static Switch Interface Board (4). Verify each label for each connector.
- Tighten the two mounting bolts at the top of the module to
4.5 N·m (40 lb in) . - Tighten the two power cables that attach to each static switch module to
11.9 N·m (106 lb in) . Verify that the cap for the snubber is attached. - Install tie-wraps on the following connectors: "J1", "J7" and "J9" .