Overview
Overload limiters are electromechanical safety devices designed to protect lifting equipment from damage due to excessive loading. They form a mandatory component in modern crane systems under international safety regulations like OSHA 1910.179 and EN 13001. Originally developed in the 1970s, these devices have evolved from simple mechanical switches to advanced microprocessor-based systems with data logging capabilities. Modern variants integrate with IoT platforms for predictive maintenance in Industry 4.0 environments.
Structure and Working Principle
A standard overload limiter consists of three subsystems: load sensing (strain gauges or hydraulic sensors), processing unit (microcontroller with preset algorithms), and actuator (relay or contactor). The system continuously compares actual load against the configured Safe Working Load (SWL). When the load reaches 90-110% of SWL (adjustable), the device triggers a two-stage response: first an audible/visual alarm at 90%, followed by power cutoff at 110%. Advanced models feature progressive braking to prevent load swing during emergency stops.
Key Features
Modern overload limiters offer IP65-rated enclosures for dust/water resistance and CAN bus communication for fleet monitoring. High-end models include black box recorders for accident investigations. Critical specifications include measurement accuracy (±1% FS typical), response time (<200ms), and operating temperature range (-20°C to +60°C). Wireless variants using LoRaWAN technology eliminate cabling in rotating equipment like tower cranes.
Application Areas
Primary applications include bridge cranes in steel plants, harbor container cranes, and construction tower cranes. The maritime sector uses marine-certified limiters on shipboard lifting equipment. Specialized versions serve niche markets: explosion-proof models for oil rigs, miniature units for theatrical rigging, and high-speed variants for automated warehouses with chain hoists. Recent adoption in renewable energy includes wind turbine maintenance cranes.
Maintenance and Precautions
Quarterly verification with certified test weights is recommended. Sensor drift correction should follow manufacturer guidelines—typically every 2,000 operating hours or annually. Common failure modes include sensor damage from shock loads (addressed with dampening mounts) and false triggers from electrical interference (mitigated by shielded cabling). Maintenance logs must document all calibrations per ISO 12485-1 requirements.
B2B Procurement Guide
When sourcing overload limiters, verify third-party certifications (CE marking, ASME B30.20 compliance). For EU markets, ensure Declaration of Conformity to Machinery Directive 2006/42/EC exists. Key procurement considerations include: matching the limiter’s capacity to the crane’s SWL with 20% safety margin, selecting appropriate communication protocols (Profibus, Modbus RTU), and confirming after-sales support for firmware updates. Bulk buyers should request factory calibration certificates traceable to NIST standards.
Related Manufacturers
- 主营：金属壳、测控仪表、水位测控仪、超载限制器、压力传感器、荷重测控仪、荷重传感器、高度传感器
- 主营：开度荷重仪、防过卷开关、防碰撞预警系统、超载限制器、力矩限制器、起重量限制器、升高度限制器、抱杆监测系统、防扭钢丝绳在线监测、弧门闸门倾角开度仪、冶金吊安全监控系统、声波吹灰器、风速仪、防触电系统、重锤限位器、水位测控闸门、汽车吊履带吊
- 主营：HSH手板葫芦、倒链、不锈钢链条、限制器、手动液压搬运车、不锈钢搬运车、不锈钢手拉葫芦、手拉葫芦、手扳葫芦、手动葫芦、环链电动葫芦、钢丝绳电动葫芦、日式鬼头电动葫芦、G80起重链条、G80锰钢链条、地牛、手动搬运车、手动地牛、日式环链电动葫芦、DHS环链电动葫芦、380v电动葫芦、三角手拉葫芦、三角手动葫芦、微型电动葫芦、电动葫芦、电动堆高车
- 主营：起重机、手动葫芦、防爆葫芦、限制器、环链葫芦、kbk轨道、专用吊具、吊装带、拉紧器、吊索具、吊环螺钉、助力夹具、起重吊带、钢板吊钳、欧式单梁、电动葫芦、气动葫芦、千斤顶、助力机械手、手扳葫芦、钢丝绳葫芦、欧式起重机、平衡吊、铝合金轨道起重机、智能起重机、卷扬机
- 主营：搬运气垫、高压软管、卷扬机、限制器、螺旋千斤顶、高压清洗机、雾化消毒门、栏木机、洗靴机、速凝剂、密闭气囊、射流器、叉车吊臂、矿用门、变压器、破拆工具、手拉葫芦、翻车机、链轮组件、推车机、搬运坦克、酸碱喷射器、蒸汽喷射器、气固喷射器、张拉机具、临时支护
- 主营：锚杆、单体液压支柱、矿用绞车、限制器、装岩机、乳化泵、矿用门、矿车
- 主营：导绳器、启闭机、起重机、限制器、卷扬机、钢丝绳、龙门吊、架桥机、轮胎吊、滑触线、电子吊秤、电缆卷筒、升降平台、永磁吸盘、轻小设备、专用电缆、吊作业车、电动葫芦、起重吊具、电动平车、液压叉车、微电叉车、手拉葫芦、伸缩臂叉车、固定登车桥、移动登车桥
- 主营：起重机监控系统、龙门吊监控系统、冶金吊安全监控系统、限制器、桥机监控、门座起重机监控、桅杆吊监控
- 主营：扭矩传感器、电子尺、接线盒变送器信号放大器。、起重机起重超载限制器、HBM传感器、仪器仪表、自动配料系统、称重配料系统、压力传感器、力传感器、电磁振动给料机、自动配料设备、真空上料机输送机投料机、粉体输送系统、配料混合系统、称重模块、电子仪表、滚珠丝杠电机丝杠、无尘投料机投料站、自动灌装秤灌装机、磁致伸缩位移传感器、拉杆式滑块式位移传感器、测力传感器、拉压力传感器、称重传感器、称重显示控制器
- 主营：龙门吊安全监控、起重机安全监控、冶金吊安全监控、超载限制器、架桥机安全监控、塔机安全监控、吊钩可视化、门机安全监控、履带吊安全监控、提梁机安全监控、升降机安全监控、卸料平台安全监控、群塔防碰撞、缆索吊安全监控、门塔机安全监控、码头起重机安全监控
- 主营：磁滞电缆卷筒、恒张力电缆卷筒、力矩电动式电缆卷筒、起重机超载、电磁吸盘、电动葫芦、电缆卷筒、双梁卷筒、起重配件、弹簧式电缆卷筒、简易龙门、起重机司机室、卷筒组、行程开关、集电器、环链葫芦、卷线器、电机、减速机
- 主营：联轴器、齿式联轴器、弹性联轴器、限制器、梅花联轴器、制动轮、联轴器膜片、柱销联轴器、滑块联轴器、凸缘联轴器、夹壳联轴器、链轮联轴器、蛇簧联轴器、万向联轴器
- 主营：压力变送器、液位传感器、物联网传感器、超载限制器、压力液位温度变送器、水浸/振动传感器、压力传感器、温湿度传感器、无线压力传感器、无线液位传感器、无线温度传感器
- 主营：龙门吊、龙门架、单梁起重机、超载限制器、双梁起重机、悬挂起重机、抓斗起重机、地平车、墙壁吊、旋臂吊、控制箱、悬臂吊、独臂吊、kbk行车、龙门起重机、电动葫芦、抓斗、电磁吸盘、教学起重机、欧式起重机、起重机配件、遥控器、缓冲器、制动器、折臂吊、大型龙门吊
- 主营：架桥机监控系统、龙门吊监控系统、门机安全监控系统、限制器、门座机安全监控系统、冶金桥机监控系统、缆索吊监控系统、起重机安全监控系统、塔机安全监控系统、红外限位器、挂篮安全监控管理系统