Operation Environment Requirements. Layout of Equipment Room. Lightening Protection and Grounding Requirements, страница 3

Figure A-2 Internal partition wall of the equipment room

A.3  Cleanliness of the Equipment Room

Dusts on the equipment may lead to electrostatic adherence, and consequently result in poor connection between metal connectors or connecting points. This will reduce the service life of the equipment, and even makes it faulty. Table A-2 shows the specifications for the density and diameter of dust particles in the equipment room

Table A-2 Limits of dust diameter and density in equipment room

The equipment room shall be guarded against dust and corrosion by harmful gases such as SO₂, H₂S, NH₃, and NO₂. Table A-3 shows the limits for them.

Table A-3 Limited density of harmful gas in equipment room

To meet the above requirements, the following measures can be taken:

n  Keep the equipment room far away from pollution sources.

n  Seal the doors and windows.

n  Always wear clean lab coat and protective footwear before getting into the equipment room.

n  Cover the ceiling and walls of the equipment room with wallpapers or lusterless paint (pulverized paint prohibited) to prevent dust flake-off.

A.4  Temperature and Humidity

Proper temperature and humidity should be maintained inside the equipment room for the transmission equipment to work well constantly, as shown in Table A-4. Too high or low temperature or humidity will do harm to the transmission quality and service life of the equipment. Too high relative humidity in the equipment room for a long period will greatly jeopardize the equipment. It will cause poor insulation or even electrical leakage in certain insulation materials. Sometimes, it can cause changes in the mechanical performance of such materials. Moreover, the metal parts of the equipment are prone to rusting. But when the relative humidity is too low, the captive screws will become loose as the insulation washer may get dry and shrink. Meanwhile the static electricity generated in the dry climate may damage the circuits of the equipment. Too high indoor temperature will greatly reduce the reliability of the equipment. If the equipment runs in such a high temperature environment for a long period, its life will be shortened because the over high temperature will accelerate aging of the insulation materials.

Table A-4 shows the environment requirements.

Table A-4 Requirements for temperature and humidity

A.5  Corrosive Gas Control Requirements