Power Requirements

With all of these devices in the wiring closet, it stands to reason that you are going to need some power receptacles there. Telecommunications rooms have some unique power requirements. First of all, each of the many small electronic devices will need power, and a single-duplex outlet will not have enough outlets.

Additionally, these devices should all be on an electrical circuit dedicated to that wiring closet and separate from the rest of the building. And, in some cases, devices within the same room may require their own circuit, separate from other devices in that room.

Isolated Ground

The circuit should have its own isolated ground. An isolated ground in commercial wiring is a ground wire for the particular isolated outlet that is run in the same conduit as the electrical supply connectors. This ground is called isolated because it is not tied into the grounding of the conduit at all.

The wire runs from the receptacle back to the point where the grounds and neutrals are tied together in the circuit panel. You can identify isolated-ground outlets in a commercial building because they are orange with a small green triangle on them.

The wiring closet should be equipped with a minimum of two dedicated three-wire 120-volt AC duplex outlets, each on its own 20-amp circuit, for network and system-equipment power. In addition, separate 120-volt AC duplex outlets should be provided as convenience outlets for tools, test equipment, etc.

Convenience outlets should be a minimum of six inches off the floor and placed at six-foot intervals around the perimeter of the room. None of the outlets shall be switched, i.e., controlled by a wall switch or other device that might accidentally interrupt power to the system.

HVAC Considerations

Computer and networking equipment generates much heat. Place enough equipment in a telecommunications room without ventilation, and the temperature will quickly rise to dangerous levels. Just as sunstroke affects the human brain, high temperatures are the downfall of electronic components.

The room temperature should match the ambient temperature of office space occupied by humans, and keep it at that temperature year round. For this reason, telecommunications rooms should be sufficiently ventilated. At the very least, some kind of fan should exchange the air in the closet. Some telecommunications rooms are large with their own HVAC (heating, ventilation, and air conditioning) controls.

Audio Video Systems