SECTION 10.2. Equipment
Rooms or Main Distribution Frame (MDF)
10.2.2. Locating
the Equipment Room
10.2.11. Unsatisfactory
Locations
10.2.12. Electromagnetic
Interference (EMI)
Equipment rooms provide secure space and maintain suitable operating environments for large communications and/or computer equipment. The equipment room or (MDF) is typically the point of debarkation for the following services:
Equipment rooms must take in to consideration:
NEC Section 110-16 requires three (3) feet of clear working space around equipment with exposed live parts. This applies to communication equipment rooms.
It is essential that clear, unobstructed access to cable tray and conduits be provided within the equipment room. When possible entrance conduit and distribution conduit/cable tray should enter and exit on the same wall, if this is not possible cable tray inside the room should be provided for distribution from wall to wall.
Power for telecommunications equipment in equipment rooms should be supplied by feeders dedicated only to supplying that equipment (NEC Article 215). Quadplex power receptacles with separate 20 amp feeders and isolated grounds, should be mounted on every wall in the equipment room, spacing should be on six (6) foot centers, located eighty four (84) inches off the deck. Other power requirements (e.g. fluorescent lighting, motors, air conditioning equipment) should be supplied by a separate feeder, conduit, and branch panel. A number six (6) earth ground is required in all telecommunication equipment rooms.
In determining the adequate size of the equipment room (MDF) consideration must be given to what services are to be terminated there. Input from Telecommunications personnel, LAN support groups, Electronics Shop, and HVAC personnel should be considered. Minimum size for an equipment room is eight (8) feet by ten (10) feet. The actual size of the equipment room will be determined during the design phase of the project when more information, pertinent to the size and application of the building is available.
Telecommunications equipment requires heating, ventilating and air conditioning equipment to functions properly at all times. If the building's HVAC system cannot ensure continuous operation (including weekends and holidays), stand alone systems with independent controls will be required. Typical room requirements are as follows:
|
Temperature range |
64 degrees to 75 degrees F |
|
Humidity range |
30 percent to 55 percent relative |
|
Heat dissipation |
750 to 5,000 BTUs per hour per cabinet (number of cabinets to be determined through consultation with CD&C). |
All walls in equipment rooms should be equipped with plywood, floor to ceiling. Plywood should be 3/4 inch, treated with a minimum of two coats of white, fire retardant paint. Ceilings should be at least 2.6 meters high to provide space over the equipment frames for cables and suspended racks.
Equipment rooms must have adequate and uniform lighting. An intensity of 50 footcandles (LM/ft2) at 3 feet above floor level is recommended. Coordinate light fixture positions with the equipment layout, especially overhead cable trays, to ensure the light is not obstructed.
A fire alarm should be installed in all equipment rooms. Portable fire extinguishers should also be available at several places in the equipment room.
Do not locate equipment rooms in any place that may be subject to:
Because EMI causes severe problems with electronic equipment, telecommunications rooms must not be shared with electrical feeders, branch circuits of noisy equipment or transformers.