Operation Environment Requirements. Layout of Equipment Room. Lightening Protection and Grounding Requirements, страница 7

Table A-9 DC voltage specifications

3.  DC distributor and control panel

n  The capacity of the primary power supply should be designed according to the power consumption of the transmission equipment of the terminal office, and a certain margin should be reserved. Generally, high frequency switching power supplies with a high switching efficiency should be adopted, which should work in N+1 hot standby mode. There should be an output current equalizer for each power module. The failure of a single power module will not affect the normal operation of the whole DC power distribution system.

n  Each control panel can access a minimum of two groups of storage batteries. When one of them fails, the other can supply power instead.

n  Each control panel can access a minimum of 5 primary power supplies.

n  The power supply equipment should be capable of automation, so as to satisfy the non-attendant requirement.

n  When the primary power supply charges the storage batteries in floating charge mode, the number of primary power supplies put into operation depends on the load. When one primary power supply becomes faulty, it will drop out automatically, while the standby primary power supply will automatically go into operation.

n  In the case of mains outage, storage batteries will discharge. When the mains resumes, it will automatically recharge the discharged storage batteries with a current 0.1 to 0.15 times of the battery capacity. When the charging voltage reaches 56.4 V, it will automatically change to constant-voltage charging.

n  When the storage batteries are fully charged, they will automatically change to floating charge.

The OptiX optical transmission equipment also has critical restriction on random transient noises, which include the abnormal operation noise of the equipment caused by external magnetic interference and the interference from the equipment itself and the grounding cables. The shorter the duration of the transient pulse, the higher values of such transient noises can be allowed. For the allowable values, see Figure A-3.

Figure A-3 Transient noises

n  When the power supply equipment fails or works abnormally, visual and audible alarms should be given. Such alarm information should be able to be sent to the operation and maintenance center.

n  In case short circuit occurs to a tributary of the power supply system, the whole power distribution system should not be affected by the sharp voltage reduction. And the peak striking voltage should not cause any breakdowns to the transmission equipment.

A.10  Lighting in the Equipment Room

The OptiX transmission equipment room is equipped with three lighting systems: