Introduction
The motor fan-cover electronic overspeed switch integrates a speed detection sensor and electronic control unit inside the motor fan cover, with the same appearance as a 普通 fan cover, ready for use by direct replacement installation. The sensor is aligned with the motor tail fan blades, outputting a corresponding number of pulse signals per revolution; the control unit calculates real-time motor speed via pulse frequency and compares it with the set rated speed. When overspeed occurs due to brake failure or motor runaway, the control unit outputs a relay signal within 0.1s to cut off hoisting power with simultaneous audible and visual alarm. Adopting fully sealed structure with protection grade IP65, it is dust-proof and moisture-proof, adapting to harsh environments such as workshops and outdoors, widely compatible with various electric hoists and lifting motors, serving as an upgraded alternative to traditional centrifugal overspeed switches.
Our Advantage
Product appearance matches standard motor fan cover, installation completed by directly replacing the original fan cover, no need to modify motor shaft, add couplings or drill holes, reducing installation time by 80% with extremely low renovation cost.
Sensor directly detects motor fan blade speed, strictly synchronized with hoisting mechanism speed, no intermediate transmission error; response time ≤0.1s upon overspeed, triggering protection at early stage of hook slipping, with safety far superior to drum-end detection.
Using photoelectric or Hall non-contact detection principle, no mechanical friction between sensor and fan blades, no wear parts, requiring no maintenance under normal use with service life over 10 years, far superior to centrifugal mechanical overspeed switches.
Control unit and sensors are all sealed inside the fan cover housing with protection grade IP65, dust-proof, moisture-proof and oil-proof, maintaining stable and reliable operation even in dusty and humid metallurgical and foundry workshops.
Overspeed trigger value can be flexibly set within 100%~150% of rated speed via buttons or software, compatible with lifting motors of different pole numbers and speeds, covering 0.5t~100t various electric hoists 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 Motor Power | 0.8~7.5kW | 13~18.5kW | 22~30kW | 37~45kW |
| Applicable Fan Cover Dia. | Φ150~Φ250mm | Φ250~Φ350mm | Φ350~Φ450mm | Φ450~Φ550mm |
| Sensor Type | Photoelectric / Hall type (optional) | Same as left | Same as left | Same as left |
| Rated Speed Range | 900~2800 rpm | 700~1400 rpm | 500~1000 rpm | 300~750 rpm |
| Overspeed Trigger | 115%~130% of rated speed (adjustable) | Same as left | Same as left | Same as left |
| Response Time | ≤0.1s | ≤0.1s | ≤0.1s | ≤0.1s |
| Output Contact | Relay NO + NC | Same as left | Same as left | Same as left |
| Contact Capacity | 5A / 250VAC | 5A / 250VAC | 10A / 250VAC | 10A / 250VAC |
| Alarm Mode | Audible & visual alarm | Same as left | Same as left | Same as left |
| Power Supply | DC 24V / AC 220V (optional) | Same as left | Same as left | Same as left |
| Protection Grade | IP65 | IP65 | IP65 | IP65 |
