Huabao Golden Samurai UPS Power 2020.7.8

With the rapid development of computer network technology, UPS equipment has been used more and more widely. It can be seen everywhere in a large number of data centers, network centers, billing certification centers, IDC computer rooms, medical institutions, and other important occasions. Figure. However, it is extremely difficult to replace the UPS after its service life has expired or because of failure. That is to ensure the normal operation of the power receiving equipment, but also to ensure personal safety. Huabao Golden Samurai gold medal agent Hangzhou Roche successfully cut over two three-phase Golden Samurai 30KVAUPS without power failure in May this year.

1. Cutover background: Two Golden Samurai 30KVA UPSs are installed on the 5th floor of a medical institution. They operate in a master-slave series hot backup mode, and the output of the slave is used as the bypass input of the master. In the past year, there have been phenomena such as internal absorption resistor burnout, input filter capacitor leakage, out of synchronization with the input power supply, and multiple freezes of the cooling fan. Communication safety cannot be guaranteed.

The output cable of the UPS equipment is connected to the AC/DC integrated screen (hereinafter referred to as the load distribution screen) in the data room for distribution. The main loads carried are data broadband network management, ATM/FR, DDN, packet and access equipment network management workstations, and backbone network routers. , Imaging centers, surgery centers and other equipment, the impact and loss of power cut and cutover are relatively large. Moreover, it is difficult and wasteful to re-lay out four-core power cables.

The company installed three new 50KVA UPS equipment next to the original UPS equipment, operating in a two-master and one-backup mode, with surplus capacity, and reserved a spare three-phase air switch on the output cabinet.

2. Cutover preparation

1. Establish a cutover working group, formulate cutover plans and emergency plans, and organize their implementation.

2. A stable and reliable backup synchronous power supply all the way. It can be provided by a backup diesel generator set with good performance. The company's high-voltage introduction is connected to two dedicated lines from two independent substations. Therefore, the other AC power is used as a cutover synchronous power source.

3. A three-and-a-half-digit digital multimeter and a phase sequence meter.

4. Cutting tools: socket wrenches, adjustable wrenches, wire cutters, crimping tools, etc. Take corresponding protective measures for the metal tools that need to be used to ensure reliable insulation.

5. One AC four-core temporary multiplexed cable, one pair of insulating gloves and one pair of insulating overshoes.

3. Key Points of Cutover

AC non-stop cutover must be the same as DC non-interrupted cutover. The method must be multiplexed and then disconnected. The key is that the AC voltage is relatively high, and the voltage and phase change with time, so during the cutover process The following two points must be noted:

1. Attention must be paid to safety, including personal and equipment safety. Take precautions to prevent short circuit and leakage.

2. When the AC power is multiplexed, the phases must be the same, and the voltage difference between the same phases should not be too large to avoid circulating currents between systems.

3. The cutover time should start at midnight, and the corresponding data backup should be done half an hour before the cutover.

4. Cutover steps

1. Lay a 25 square four-core cable from a three-phase 100A air switch on the AC power distribution panel (hereinafter referred to as the air-conditioning panel) used by the data room for special air conditioning in the computer room to the load distribution panel for temporary multiplexing.

2. Turn the 100A air switch on the AC screen of the air conditioner to the off position, connect one end of the temporary cable to the outlet end of the 100A air switch, and make a copper nose at the other end, cover it with a 10CM tube, and wrap the insulating tape. .

3. Under the premise of ensuring that the standby power supply is stable and reliable (the diesel generator can be used for power supply), convert the original 30KVA UPS to bypass power supply, and test the bypass AC input power supply on the load distribution screen and the market on the AC screen of the air conditioner. The electrical phase sequence is the same.

4. Connect the middle line of the temporary cable to the working ground row of the AC screen of the air conditioner and the working ground row of the load distribution screen.

5. Find suitable multiple contacts at the output back end of the main switch of the load distribution screen, and test the voltage between the AC A, B, and C three-phase multiple contacts and the 100A air switch inlet row A, B, and C on the AC screen of the air conditioner. , Theoretically the voltage is 0, the minimum value between the same phases in the actual test is 0.3V, and the maximum one-phase difference is 1.55V.

6. Connect the temporary cables corresponding to phases A, B and C to the multiple contacts on the load distribution screen.

7. Close the 100A air switch on the AC screen of the air conditioner. At this time, the two AC power lines are running in parallel and observe the system status (if there is an abnormality, the air switch can be quickly disconnected and the load is still supplied by the original bypass power supply).

8. Wait for the system to run stably for about 3 minutes. If there is no abnormality, turn off the input switch on the load distribution screen. At this time, all data devices are provided with AC power on the AC screen of the air conditioner.

9. Shut down the old UPS equipment, remove the connecting cable between the output cable and the UPS equipment, and pull it out from the ground trough and connect it to the spare 63A three-phase air switch on the newly installed UPS output cabinet.

10. Connect the new UPS equipment to the bypass for power supply. Close the input switch on the load distribution screen of the data room, and test the phase sequence of the AC power at the inlet and outlet ends of the 63A three-phase air switch (the upper and lower ends of the switch lead to the AC bypass mains and load distribution on the new UPS output screen AC on the screen), after confirming the same, close the 63A air output switch.

11. Observe the operation of the system (if there is an abnormality, the 63A air switch can be quickly turned off, powered by the AC panel of the air conditioner), and the system runs stably for about 3 minutes to disconnect the 100A air switch on the AC panel of the air conditioner).

12. Remove the temporary multiplexed cables; change the new UPS from bypass power supply to normal power supply.

The uninterrupted cutover of alternating current is a relatively dangerous task and is not worth promoting. Under the condition that the load is allowed to be interrupted, Hangzhou Roche engineers believe that ensuring personal safety should be the primary purpose and carry out the interruption and cutover of AC power. In the case of Wan Feiwei, I hope this article can help you.