Introduction
This switch combines centrifugal mechanical structure with micro-switch, featuring compact design and reliable action. No external power required (mechanical type), it rotates synchronously with the motor shaft. When the limited speed is reached, it triggers a contact signal into the crane control circuit for overspeed protection. Widely used in metallurgical cranes, double girder overhead cranes and gantry crane hoisting mechanisms.
Description
The shaft-mounted electronic overspeed switch is designed for double girder overhead cranes. Directly mounted on the YZR motor shaft end, it monitors hoisting mechanism speed in real time. When speed exceeds the set value, it quickly cuts off the control circuit to prevent runaway and hook drop accidents. Essential safety protection for metallurgical, foundry and heavy workshop cranes.
Application
Automotive industry
Medical industry
Machinery industry
Amusement facilities industry
Clothing industry / Apparel industry
Feature
Dual-beam shaft head electronic overspeed switch, fast response speed, high measurement accuracy, anti-electromagnetic interference, trigger protection when overspeeding, safe and reliable, simple mounting.
Our Advantage
Shaft Direct Mounting：Mounts directly on motor shaft flange without intermediate transmission, high alignment accuracy, easy installation and maintenance.
Fast Overspeed Response：Instantly trips at 120% rated speed, cuts hoisting circuit, effectively preventing hook drop and shaft failure.
Reliable Mechanical Design：Pure centrifugal principle, immune to electromagnetic interference, stable and no false tripping in harsh workshop environments.
Wide YZR Compatibility：Fits 6/8/10-pole YZR metallurgical motors, covering 3.2t~100t double girder cranes, easy replacement.
Dry Contact Output：NO/NC dry contacts directly wired into crane control circuit, no external power needed, easy retrofit.
Technical Specifications
| Rated Load | Motor | Poles | Rated Speed | Tripping Speed | Model Ref. |
| 3.2t ~ 5t | YZR132M | 6P | 1000 r/min | 1200 r/min | LY1-2/600D |
| 5t ~ 10t | YZR160L | 6P/8P | 1000/750 r/min | 1200/900 r/min | LY1-2/600D / 750D |
| 10t ~ 32t | YZR200L | 8P/10P | 750/600 r/min | 900/720 r/min | LY1-2/750D / 1000D |
| 32t ~ 50t | YZR225M | 10P | 600 r/min | 720 r/min | LY1-2/1000D |
| 50t ~ 100t | YZR280S | 10P/12P | 600/500 r/min | 720/600 r/min | LY1-2/1000D / 1200D |
Core Parameters
| Item | Specification |
| Rated Load | 3.2t ~ 100t |
| Applicable Crane | Double girder overhead crane |
| Mounting | Motor shaft flange direct mount |
| Rated Speed | 750 / 1000 / 1500 r/min（by motor poles） |
| Tripping Speed | 1.2× rated speed |
| Duty Class | M5 ~ M6 |
| Power Supply | AC 380V / 50Hz |
| Contact Rating | AC 380V 5A |
