User's Manual

RadioFrame System Method of Procedure GSM/802.11b
Pre-Installation
24 RadioFrame Networks, Inc.
Earthquake-resistant design should be contracted to a firm specializing in such work.
However, the following general considerations need to be observed and factored into a
seismic design program:
• Equipment shall not be secured to both the shelter walls and floors, since dissimilar
movement between these surfaces is likely in an earthquake.
• Mounting should provide for some "sway" in the overall equipment mounting, thereby
absorbing the energy of an earthquake. This is typically accomplished by rigid
mounting of racked equipment or cabinets at the base, while semi-rigidly attaching
the rack top using 1/8 in (3.2 cm) diameter steel braided wire rope. Wire rope
anchors are then secured to ceilings joists. The benefit of this type of installation is
that racks are allowed to sway within limits but can't fall over.
• Cabinet designs with wide footprints can be used to help prevent cabinets from
tipping over.
• Columns of cabinets stacked and bolted back-to-back present a very stable and wide
footprint. The bottom cabinets shall still, however, be bolted to the floor for complete
security.
• Some cabinets can be outfitted with outrigger-type support legs to prevent tip-over.
These outriggers alone do not provide adequate earthquake protection, but are
typically adequate if the cabinet is bolted to the floor.
NOTE: If a rack is seismic rated, any add-on aftermarket equipment or equipment
that is not seismic rated will render the overall package as not being seismic tested
and certified as a unit. Therefore, the unit would no longer be considered as seismic
rated.
• When bolting down to computer floor, be sure to anchor all the way to the subfloor.
• Columns of cabinets must be supported, though not rigidly. Rigid mounting will result
in extreme vibration and resultant mechanical failure during an earthquake. Semi-
rigid mounting is preferred. Semi-rigid
bracing is defined as bracing which allows a
measurable amount of movement.
• Some computer floors lose mechanical integrity if several panels are simultaneously
removed. This could lead to equipment floor collapse during at earthquake. The
flooring manufacturer shall be consulted for floor removal procedures.
• Equipment shall be stabilized by a top support. This is critical in preventing a column
of equipment from toppling, causing injury to personnel. The footings cabinet
columns and racks shall be bolted to the floor as appropriate, using concrete
anchors. Sometimes the cabinet columns are placed on C-channel tract or wooden
pedestals.
• Cables and transmission lines should not be installed rigidly, and without strain relief.
Make broad service loops.
• Lighting fixtures should be prevented from swaying by the addition of one or more
guy wires. A fluorescent lighting fixture in particular, can be very dangerous if allowed
to swing against a wall or equipment racks, shattering and spraying broken glass
below. Fluorescent lighting fixtures shall have
protective lenses or protective plastic
sleeves that cover the fluorescent tube, preventing broken glass from falling on
occupants.