RCF HDL10-A 1400W Dual 8" Active Line Array Module (Black) - Manual (Page 10)

10
ENGLISH
- Suspending loads should be done with extreme caution.
- When deploying a system always wear protective helmets and footwear.
- Never allow people to pass under the system during the installation process.
- Never leave the system unattended during the installation process.
- Never install the system over areas of public access.
- Never attach other loads to the array system.
- Never climb the system during or after the installation.
- Never expose the system to extra loads created from the wind or snow.
WARNING : The system must be rigged in accordance with the laws and regulations of the
Country where the system is used. It is responsibility of the owner or rigger to make sure that
the system is properly rigged in accordance with Country and local laws and regulations.
WARNING : Always check that all the parts of the rigging system that are not provided
from RCF are:
- appropriate for the application;
- approved, certified and marked;
- properly rated;
- in perfect condition.
WARNING : Each cabinet support the full load of the part of the system below. It is very
important that each single cabinet of the system is properly checked.
The suspension system is designed to have a proper Safety Factors (configuration
dependent). Using the “RCF Shape Designer” software it is very easy to understand safety
factors and limits for each specific configuration. To better comprehend in which safety
range the mechanics are working a simple introduction is needed: HDL mechanics are built
with certified UNI EN 10025-95 S 235 JR and S 355 JR Steel.
S 235 JR is a structural steel and has a stress-strain (or equivalent Force-Deformation) curve
like the following.
The curve is characterized by two critical points: the Break Point and the Yield Point. The
tensile ultimate stress is simply the maximum stress attained. Ultimate tensile stress is
commonly used as a criterion of the strength of the material for structural design, but it
should be recognized that other strength properties may often be more important. One
of these is for sure the Yield Strength. Stress-strain diagram of S 235 JR exhibit a sharp
break at a stress below the ultimate strength. At this critical stress, the material elongates
considerably with no apparent change in stress. The stress at which this occurs is referred
to as the yield point.
Permanent deformation may be detrimental, and the industry adopted 0.2% plastic strain
as an arbitrary limit that is considered acceptable by all regulatory agencies. For tension
and compression, the corresponding stress at this offset strain is defined as the yield.
S 355 J and S 235 JR characteristic values are R=360 [N/mm2] and R=510 [N/mm2] for
Ultimate Strength and Rp0.2=235 [N/mm2] and Rp0.2=355 [N/mm2] for Yield Strength. In
our prediction software the Safety Factors are calculated considering the Maximum Stress
Limit equal to the Yield Strength, according with many international standards and rules. The
resulting Safety Factor is the minimum of all the calculated safety factors, for each link or pin.
This is where you are working with a SF=4:
Depending on local safety regulation and on situation the required safety factor can vary.
It is responsibility of the owner or rigger to make sure that the system is properly rigged
in accordance with Country and local laws and regulations. The “RCF Shape Designer”
software gives detailed information of the safety factor for each specific configuration.
The safety factor is the result of the forces acting on fly bar’s and system’s front and rear
links and pins and depends on many variables:
- number of cabinets;
HDL20-A, HDL10-A SUSPENDED
“RCF SHAPE DESIGNER”
SOFTWARE AND SAFETY
FACTOR
Ultimate
Strength
N/mm 2
Yield
Strength
SF = 4
Working
Conditions
%
Ultimate
Strength
N/mm 2
Yield
Strength
SF = 4
Working
Conditions
%
WARNING
WARNING
WARNING