XLC-127, XLC-127+ and XLC-118 Overall Enclosure Structural-Strength Ratings
The actual strength of the XLC enclosures will depend on the complex total of the combined forces from each of the rigging points acting on the enclosure as a whole and will vary with the array configuration. However, for the sake of simplicity, Electro-Voice chooses to define the work- ing-load limit of the overall enclosures as the sum total of the weight of that enclosure plus the weight of all of the enclosures and rigging hardware suspended below. This simplified working- load weight rating of the overall enclosures is defined as being independent of the angles of pull on the individual rigging points. The Electro-Voice engineers have chosen to define the working- load limits of the individual rigging points as a function of pull angle so that they take into account any variations in enclosure strength that might occur as a function of pull angle. This approach allows the enclosure working-load limit to be defined as independent of pull angles, making the complex structural rating analysis easier. The overall enclosure strength ratings are identical for the XLC-127, XLC-127+ and XLC-118, and are shown in Figure 11.
CAUTIONS for a Complex Structural Rating Analysis
WHEN APPLYING A COMPLEX STRUCTURAL RATING ANALYSIS TO ANY XLC LOUDSPEAKER SYSTEM SUSPENDED OVERHEAD, THE USER MUST OBEY THE FOLLOWING RULES:
1.Never exceed the front-to-back angle limits for the front button-bar assemblies on any enclosure. Never exceed the side-to-side angle limits for the front button-bar assemblies on any enclosure.
2.Never exceed the front-to-back angle limits for the rear swing-arm assemblies on any enclosure. Never exceed the side-to-side angle limits for the front swing-arm assemblies on any enclosure.
3.Always make sure that every front button bar is securely locked in the front rigging tube on every enclosure (and grid, when applicable) before lifting overhead.
4.Always make sure that every rear swing arm is securely locked in the rigging frame with the quick-release pins on every enclosure (and grid, when applicable) before lifting overhead.
3.5Wind Loading
The XLC loudspeaker systems have been designed to withstand winds of up to 60 miles per hour (96.6 kilometers per hour) if the bottom cabinet is rigidly secured. For obvious safety reasons, Electro-Voice urges the user not to suspend any loudspeaker systems overhead outdoors when high winds are expected. When suspending XLC loudspeaker systems outdoors, the user is strongly encouraged to rigidly tie off the bottom cabinets in all arrays as a safety precaution against unexpected high winds.
A pull-up grid with an attached strap may be used to secure the bottom cabinets. The tie-off assembly must have a working-load rating of 2,000 lb (907 kg). A ratchet strap with a 2,000-lb working-load rating must be used for the pull-up assembly.
