ELECTRO-VOICE
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Xi-A Rigging Manual
14
4.3 Special Safety Considerations for Rigging Strap Assemblies
4.3.1 Redundant Attachment Points
As an added safety measure, it is suggested that the user install a second set of grid straps from
the top rigging points of the top cabinets in an array back to the grid (or building structural
supports). These redundant safely straps can be secured to an open section of rigging track next
to the primary grid straps. The safety straps should have as little slack as possible (less than one
inch is preferable).
4.3.2 Special Considerations for Polyester Webbing
The GS-1B, LS-1B and LS-2B utilize polyester webbing in their construction. The user is
cautioned, however, that in certain permanent installation applications, the polyester material may
not meet local fire regulations. The user is also cautioned that polyester material will deteriorate
with extended exposure to ultraviolet light (direct sunlight) or to hot, dry environments, resulting in
reduced strength capability. In such instances, wire rope or chain assemblies must be substituted.
4.4 Special Safety Considerations for Grid & Building Structural Supports
When suspending loudspeaker arrays from grids or building supports the associated rigging
hardware employed (i.e., rigging straps, slings, chains, wire-rope assemblies, chains, etc.) may
not hang at a 0° vertical angle. These vertical angle differences will result in forces (i.e., tension
loads) in that rigging hardware that are greater than the weight suspended below. These
increased forces must be taken into account when evaluating the load on the mechanical
components and the safety factor of an array. The greater the angle difference from the 0°
vertical, the greater is the increase in force above what it would be if the straps were at 0°. Any
users unfamiliar with the process of calculating the increased load as a function of lifting angles
should consult the list of references in Appendix B.2 which cover the topics of rigging and
engineering mechanics.
Attention: Array details and rigging configurations will affect the load on the building
structure, the grids, the loudspeaker systems, the rigging straps and all associated
rigging hardware. The user is responsible for determining the loads on all of the
mechanical components throughout the loudspeaker array, and for ensuring that the
working-load limits and resulting safety factors are not exceeded. A qualified
structural engineer should be consulted to evaluate the design.
