Operation Environment Requirements. Layout of Equipment Room. Lightening Protection and Grounding Requirements, страница 6

A.9  Power Supply

The working power voltage for OptiX OSN 9500 ranges from -38.4 V to -57.6 V. The transmission equipment offers a transmission path for communication networks, so its interruption will have a wide influence. Therefore, the DC power distribution system should be protected against power failure and configured with storage batteries. To deal with a long-term power outage, a diesel generator should be equipped as the standby AC power supply for the backbone transmission equipment. The DC power supply system consists of storage battery, primary power supply (rectifier), DC distributor and control panel.

1.  Storage battery

Storage battery is an essential component of the DC power distribution system of OptiX OSN 9500. It functionally serves to:

n  Stabilize the voltage for the transmission equipment to work reliably.

n  Store energy. In the case of outage of mains, the storage battery can feed power for a period of time, which depends on its capacity, so that the communication will not be interrupted immediately.

n  Filter for large capacitors. The storage batteries are useful for absorbing surge voltage from rectifiers and preventing noise and power frequency interference from getting into the communication equipment.

n  Automatically shut down. When the voltage of the storage battery drops to below -43 V, the control circuit can automatically shut down the output.

The storage battery of OptiX optical transmission equipment is charged and discharges under a low, constant voltage. Table A-8 shows the relevant requirements.

Table A-8 DC charge/discharge status and voltage requirements

2.  Primary power supply (rectifier)

n  Primary power supplies shall be able to operate in parallel, and there should be current equalizing device between them.

n  The primary power supplies should be equipped with a current limiting device.

n  The output voltage of the primary power supply should meet the requirement for initial charging of storage batteries, that is 2.35 × 24 = 56.4 V DC (when the power supply is -48 V DC)

n  A DC voltmeter and an ammeter should be installed for the primary power supplies.

n  The efficiency of the primary power supply should be more than 85% and its power factor more than 0.8.

n  Natural cooling is recommended for the primary power supply. The primary power supply should be able to work continuously with full load within 0°C – 40°C.

n  The output noise voltage (measured with a psophometer, plus weighing factors) of the primary power supply should meet the requirements shown in Table A-9.

n  The primary power supply should be able to automatically shut down the output at a low voltage.