Information Technology Reference
In-Depth Information
in one room. Standard practice in the United States is to equip each dedicated out-
let location with a bright orange outlet (either a duplex or simplex receptacle) to dis-
tinguish it. The electrical circuit should be rated appropriately for the equipment
that is to be connected. Some larger equipment may require its own separate dedi-
cated outlet.
You should be sure that an adequate number of electrical outlets are provided,
based on the equipment that needs to be installed. Racks or banks of equipment
may need an outlet strip or a power bar with multiple outlets. Allow lots of room
for growth. A good rule of thumb is to provide twice the number of outlets you
think you will need, and double that number! Remember to include open outlets
that can be used to provide power to test equipment.
The standard recommends two dedicated duplex outlets, AC outlets for equip-
ment power, rated at 15 A, 110 V (or appropriate ratings for your locale) on sepa-
rate circuits. It also recommends convenience outlets, wall-mounted every 1.8 m (6
ft) around the telecommunications room, in addition to any power requirements for
collocation of an equipment room. Also specified is lots of ceiling mounted lighting,
540 lux (50 ft-candles). Equipment roomss should have enough HVAC capacity to
maintain the room at 18 to 24°C (64 to 75°F).
Another item to consider is power conditioning and backup power. Your
power connections should, at the minimum, contain surge protection. In areas that
are subject to power-line fluctuations, you might want to consider ferro-resonant
transformers that automatically compensate for sags and minor surges. True power
spikes must be dealt with by the use of line surge protectors. Several types of these
exist, including gas-discharge protectors, semiconductor protectors, and metal-
oxide varistors (MOVs). The MOVs are the most common and the cheapest, and
provide the least protection—usually found in low-cost multi-outlet strips. Their
primary drawbacks in such an application are their slow response time and the
user's inability to determine if they have lost protection because of prior spikes.
A form of spike also occurs as a result of telecommunications wires that run
outside your building. The most common occurrence results from a nearby lightning
strike. The electrical discharge may induce destructive voltages in any outdoor
cabling, including telephone and LAN cabling. It is very important to provide
approved protectors on all telecommunications cables at the point of entry to your
building. Fiber-optic cabling with no metallic members can be an important tool in
eliminating lightning risk.
Another potential power problem is a power outage. Equipment that might be
disrupted by a power outage should have emergency backup power supplies pro-
vided. These power supplies usually connect between the equipment to be served
and the AC power outlet. One type of uninterruptible power supply (UPS) is the
