Maintenance of Generator Power Distribution Cabinet

Power distribution cabinet is an indispensable part of diesel generator set. During the operation of the diesel genset, it is inevitable that it will cause certain wear and tear to the distribution cabinet. In order to make the life cycle of the distribution cabinet of the generator set last for a long time, it is necessary and important to do maintenance to the distribution cabinet.

Gen Set Power Distribution Cabinet Maintenance - Preparation

1. When doing maintenance to the distribution cabinet, inform customers in advance of power outage.

2. Do all the preparation work before the power outage, especially the preparation tools of the genset should be complete.

3. Unified command by project manager, the personnel participating in the maintenance work are unified in action, and the division of labor is reasonable, so that the work can be completed efficiently.

Gen Set Distribution Box Maintenance – Power failure

1. Disconnect the automatic air switch of the diesel generator, put the selection switch in “Stop” position, disassemble the positive and negative line of the battery, and hang the warning sign to prevent the generator from transmitting electricity.

2. Disconnect the low-voltage side air switch step by step, then disconnect the load switch on the high-voltage side of the transformer. After confirming the disconnection position, close the ground switch, then lock the high-voltage cabinet with the lock, and hang the sign of "someone is operating, no closing".

3. Open the door of the distribution cabinet and check the low voltage busbar in the power outage state with the test pencil. Check if there is any deformation at the busbar joint, whether there is any blackening of the discharge, and tighten the coupling bolts. If the bolt is rusted, it should be replaced to ensure that the joint is tightly connected. Check the insulators on the busbar for looseness and damage.

4. Use the handle to shake the total air switch out of the power distribution cabinet, check whether the main contact has the mark of burning and melting, check whether the arc extinguishing cover is burned black and damaged, tighten the wiring screws, clean the dust inside the cabinet, and test the machine closing and opening situation.

5. Take out the sub-switch cabinets from the drawer cabinet, check and tighten the terminals of the current transformer, ammeter and watt-hour meter. Wiring, check the flexible reliability of the handle operating mechanism, tighten the air switch in and out line, and clean the dust in the switchgear and the outgoing line behind the power distribution cabinet.

6. When maintaining the capacitor cabinet, first disconnect the main switch of the capacitor cabinet, discharge the capacitor one by one with the wire of 25mm or more, then check and tighten the wiring screws of the contactor, reactor, and capacitor, whether the grounding device is good, check the capacitor for bloating and use a vacuum cleaner to clean the dust in the cabinet. After the maintenance is completed, clean the tools and evacuate the site. A 500V megger is used to measure the insulation resistance of the busbar to the busbar and the busbar to the ground above 0.5M.

Gen Set Distribution Cabinet Maintenance – Trail Operation

1. Disconnect the earthing switch on the high voltage side of the transformer, confirm the disconnection position, close the load switch on the high voltage side of the transformer, observe whether the no-load operation of the diesel generator set transformer is normal, then lock the high voltage switch cabinet with the lock and remove the sign. Close the low-voltage side air switch step by step and check if the low-voltage power distribution cabinet is working properly.

Attention

1. Power should be checked after power failure.

2. When the power distribution cabinet is maintained in sections, an isolation device shall be installed at the junction of the live and unpowered distribution cabinets.

3. When operating the high-voltage side vacuum circuit breaker, should wear insulation boots, wear insulated gloves, and have special personnel to monitor.

4. When maintaining the capacitor cabinet, it is strictly forbidden to touch before the capacitor is discharged to the ground.

5. Before power transmission after maintenance, check if there are any tools left in the power distribution cabinet.

Distribution Cabinet Operation Procedures

1. The power distribution cabinet is the normal operation of the ship's power distribution center and the equipment, and any unrelated personnel shall not pull the switch on the board.

2. After the generator set is started, the power screen speed up switch should be used to accelerate the generator manually and slowly until the generator enters the normal working state, and the voltage and frequency reach the specified value before closing for power transmission.

3. After the switchboard enters the power distribution state, it is not allowed to unplug the power panel speed-up switch at will. The lock switch of the air circuit breaker shall not be used in non-emergency situations.

4. Parallel operation of generators must be carried out strictly accordance with the requirements and regulations of the parallel operation conditions. It is necessary to pay attention to the phenomenon of reverse power (countercurrent) and failure of the parallel operation.

5. When stopping the machine, the generator load should be cut off first, then stop without load, and no direct shutdown should be carried out with load.

6. When interleaving the shore electricity, the power switches of the shore power screen should be cut off first, and then the correctness of the wiring and phase sequence should be checked. After confirming the correctness, the conversion of the ship shore power can be implemented, and the operation with load is strictly prohibited.

7. The power distribution cabinet should be cleaned and maintained regularly to keep the equipment in good working condition.

8. When the generator is working, the turbine personnel should concentrate on thinking and carefully operate the switchboard to prevent accidents, otherwise the individual accident liability will be investigated.

9. The charging and discharging board is the ship emergency power distribution board. The engineers on duty should check its working condition at any time to ensure the low voltage power is sufficient and master the working condition of the magnetic saturation voltage regulator through the instrument on the board.

10. During normal navigation, the switches on the switchboard should be turned on to ensure that the generator can be started at any time and ready for use.