Boom Crane Limiter & Indicator Standard ISO 10245-6:2008 Explained
ISO 10245-6:2008 "Cranes — Limiters and indicators — Part 6: Jib cranes" is the dedicated safety device standard for jib cranes. It specifies the technical requirements for load moment limiters, lifting capacity limiters, radius indicators, height limit switches, and anemometers used on portal base, mast, deck, and floating jib cranes.
Load Moment Limiter (LML) Technical Requirements
Jib crane load moment limiters must accommodate the multi-condition operating nature of these machines, automatically switching load curves based on current boom length, boom angle, and pulley ratio. The LML shall provide real-time load moment monitoring, issuing an audible and visual pre-warning (buzzer ≥85 dB plus flashing red light) when the moment reaches 90% of the rated capacity, and automatically stopping hoisting and radius-increasing movements at 100%, while still permitting lowering and radius-decreasing operations. Combined accuracy shall be within ±5%, and sensor zero-point drift shall not exceed ±0.1%/°C over an ambient temperature range of -10°C to +55°C. The LML shall store at least 500 overload events, including time, moment values, and action results, with data retention of no less than 10 years after power loss. Parameter settings shall be password-protected to prevent unauthorized modification. Load curve switching is a jib crane-specific feature — different boom length combinations, telescopic boom extensions, auxiliary jib installations, and tower-mode configurations each correspond to distinct rated lifting capacity curves. The LML must automatically identify the current operating condition and call up the appropriate load parameters.
Safety Device Requirements for Jib Cranes
The radius indicator shall display the current working radius in real time — the horizontal distance from the hook center to the slewing center — with an accuracy of ±2% or ±0.1 m, whichever is greater. For telescopic boom cranes, the radius indicator shall be calibrated in segments according to different boom length combinations. The height limit switch shall issue a pre-warning 1 m before the hook reaches its highest position and automatically stop hoisting at 0.3 m from the limit. The slewing angle limiter shall provide a pre-warning within ±2° of the set angle limit and stop slewing when the limit angle is reached. The anemometer shall be mounted at the boom tip or tower top, issuing a pre-warning when wind speed reaches the working limit, automatically stopping operations at 20 m/s, and at 27 m/s. All safety devices shall have a protection rating of at least IP54, with outdoor control stations rated IP65 or higher. Sensors shall be rated IP67 minimum, with shielded connecting cables routed through metal hose.
| Device | Function | Setpoint |
|---|---|---|
| Load moment limiter (LML) | Torque Monitoring Protection | 90%early warning/100%Stop |
| Radius indicator | Real-time Working radius Display | ±2%Or±0.1m |
| Height Limit Switch | Hooklimit switch | -1mearly warning/-0.3mStop |
| slewing angle limiter | slewing limit | Setting±2° |
| Anemometer | Wind Speed Monitoring | 20m/searly warning/27m/s Stop |
Testing & Calibration
All safety devices on Kelude jib cranes undergo rigorous type testing and factory inspection before shipment. The load limiter is accuracy-tested at 25%, 50%, 75%, 100%, and 110% of rated load, with three measurements taken at each point; the combined deviation must stay within ±5%. Environmental testing covers storage at temperatures from -20°C to +60°C, followed by functional and accuracy checks. Vibration testing is performed across a 5–200 Hz range at 2g. Routine factory tests verify self-diagnostic functions, early warning and limiting functions, display accuracy, and calibration at the 50% and 100% load points.
For ongoing reliability, the lifting capacity limiter is calibrated monthly using standard test weights at 50% and 100% of rated load, with a permissible deviation of ±3%. Every six months, a full five-point calibration of the load limiter is carried out using force sensors at 20%, 50%, 75%, 100%, and 110% of the measuring range, allowing a deviation of ±5%. The anemometer is calibrated annually with a tolerance of ±3%. All Kelude heavy industry jib crane safety devices complete the full type test and factory acceptance test prior to delivery.
| Test | Cycle | Method | Standard |
|---|---|---|---|
| Type Test | At Type Approval | 5Point Loading3Times/Times | ±5% |
| routine test | Per Unit | 2Point Calibration Function | ±5% |
| Lifting Capacity Limiter / Load Limiter | Monthly | 50%/100% | ±3% |
| LML | Semi-annually | 20%~110% | ±5% |
| Anemometer | Annually | Calibration | ±3% |
Frequently Asked Questions
Q: What is the difference between a jib crane load limiter and a general-purpose load limiter?
A: A jib crane load limiter is designed for multi-condition operation. It automatically switches between the appropriate rated lifting capacity curves based on the current boom length (telescopic boom extension), boom angle, and jib attachment configuration. Combined error ≤ ±5%, with capacity to store 500+ overload events and password-protected parameter settings.
Q: What accuracy is required for the radius indicator?
A: The working radius is displayed in real time with an accuracy of ±2% or ±0.1 m, whichever is greater. For telescopic boom cranes, the indicator should be calibrated in segments corresponding to different boom length combinations. Sensors are mounted at the boom base or luffing pivot point with a protection rating of at least IP65.
Q: How often should safety devices on jib cranes be calibrated?
A: The lifting capacity limiter should be checked monthly at two load points (50% and 100%) with a deviation of ≤ ±3%. The load limiter requires calibration every six months at five load points (20%, 50%, 75%, 100%, and 110%) with a deviation of ≤ ±5%. Limit switches need a monthly functional check, and the anemometer should be calibrated annually.
Q: What safety equipment does Kelude install on its jib cranes?
A: Our jib cranes are equipped with a load limiter system compliant with ISO 10245-6:2008, featuring automatic load curve switching for various operating conditions and overload event logging. Sensors are rated IP67 with shielded connecting cables protected by metal hoses. Full calibration is completed before the crane leaves the factory.
