Introduction
The metering wheel encoder electronic overspeed switch consists of three parts: metering wheel mechanism, rotary encoder and electronic control unit. The metering wheel is pressed against the drum surface or wire rope, rotating synchronously with the hoisting mechanism. The encoder outputs pulse signals proportional to the rotation angle, and the control unit calculates current lifting height through pulse counting and real-time lowering speed through pulse frequency. When lowering speed exceeds the set threshold, the control unit immediately outputs a relay signal to cut off hoisting power, and can output 4-20mA or RS485 signals to upload height and speed data to the monitoring system. Adopting non-contact photoelectric encoding principle with no mechanical wear, it offers long service life and high reliability, widely compatible with various electric hoists and lifting trolleys, achieving three-in-one functions of lifting height display, upper/lower limit and overspeed protection.
Our Advantage
Using high-resolution photoelectric encoder with metering accuracy ±1cm, the control unit real-time calculates and displays current lifting height, allowing operators to intuitively grasp load position and avoiding over-hoisting/over-lowering accidents.
Real-time monitors lowering speed via pulse frequency, with response time ≤0.1s upon overspeed, immediately cutting off hoisting power, effectively preventing hook slipping and overspeed falling caused by motor runaway or brake failure, ensuring personnel and equipment safety.
Using photoelectric encoder non-contact detection principle with no mechanical wear parts, the metering wheel adopts wear-resistant polyurethane material, requiring no maintenance under normal use with service life over 10 years, far superior to centrifugal mechanical overspeed switches.
Integrating three functions—lifting height metering, upper/lower limit control and overspeed protection—replacing the traditional combination of mechanical limiter + overspeed switch + height indicator, reducing installation space and wiring, making the system simpler and more reliable.
Overspeed trigger value and upper/lower limit positions can be flexibly set via buttons or software; encoder pulse count and drum diameter are configurable, compatible with 0.5t~100t various electric hoists and different drum specifications, with extremely strong versatility.
Specification
| Parameter | 0.5~5t | 10~20t | 32~50t | 80~100t |
| Applicable Capacity | 0.5/1/2/3/5t | 10/16/20t | 32/50t | 80/100t |
| Applicable Drum Dia. | Φ200~Φ400mm | Φ300~Φ500mm | Φ400~Φ600mm | Φ500~Φ800mm |
| Encoder Resolution | 100~500 ppr | 500~1000 ppr | 1000~2000 ppr | 2000~2500 ppr |
| Metering Accuracy | ±1cm | ±1cm | ±1cm | ±1cm |
| Overspeed Trigger | 115%~130% of rated speed | Same as left | Same as left | Same as left |
| Response Time | ≤0.1s | ≤0.1s | ≤0.1s | ≤0.1s |
| Limit Points | Upper limit + upper deceleration + lower deceleration + lower limit (4 points) | Same as left | Same as left | Same as left |
| Display | LED height digital display | Same as left | Same as left | Same as left |
| Output Signal | 4 relay contacts + RS485 / 4-20mA (optional) | Same as left | Same as left | Same as left |
| Contact Capacity | 5A / 250VAC | 5A / 250VAC | 10A / 250VAC | 10A / 250VAC |
| Power Supply | DC 24V / AC 220V (optional) | Same as left | Same as left | Same as left |
| Protection Grade | IP65 | IP65 | IP65 | IP65 |
