Hongnuo (shenyang) General Machinery Co., Ltd. is one of the most reliable manufacturers and suppliers of rotating paddle level switch in China. Welcome to buy high quality rotating paddle level switch at competitive price from our factory. We also accept customized orders.
Specs at a glance
| Parameter | Value |
|---|---|
| Power supply | 110VAC / 220VAC / 24VAC / 24VDC |
| Output | Microswitch 5A / 250VAC SPDT |
| Paddle speed | 1 RPM |
| Applicable material density | ≥0.5g/cm³ (standard) / ≥0.3g/cm³ (optional) |
| Temperature range | -20°C ~ +80°C (standard) / up to 1300°C (optional) |
How it works
A low-speed gear motor turns a paddle. When material covers the paddle, it stops rotating. The motor housing rotates slightly, triggering a microswitch. That sends the signal: "material is here."
When the material level drops and the paddle is free again, a spring resets the mechanism. The motor starts turning again. The signal resets.
That's it. No electronics. No programming. No calibration.
Why rotary paddle?
What makes a rotary paddle switch the right choice for solids?
| Rotary Paddle | Capacitance Probe | Ultrasonic | Vibrating Fork | |
|---|---|---|---|---|
| Dust affects reading? | No | Yes | Yes | No |
| Material build-up causes false alarms? | No | Yes | No | Yes |
| Static electricity causes false alarms? | No | Yes | No | No |
| Works with any solid material? | Yes | No (needs calibration per material) | Yes | Yes |
| Needs calibration per material? | No | Yes | Yes | No |
| Price | Low | Medium | High | Medium |
| Simple to install? | Yes | No | No | Yes |
Key features that matter
1. Friction clutch protects the motor
When the paddle is blocked, the clutch slips, the motor keeps running but the paddle stops. A microswitch cuts motor power. No burned-out motors.
2. Mechanical seal keeps dust out
Dust is the enemy of bearings and motors. This switch has a highly integrated mechanical seal - dust doesn't get in along the shaft. Longer life. Less maintenance.
3. Torque adjustable for different material weights
Light powder? Heavy granules? Adjust the torque spring. Low torque for light materials (so the paddle stops easily). High torque for heavy materials (so it doesn't false-trigger). One switch adapts to your material.
4. High temperature options available
Up to 1300°C. Cement clinker. Calcined materials. Hot ash. Not just a room-temperature switch.
5. Multiple mounting options
Thread (G1", G1-1/2", G3/4") or flange. Match your existing tank opening. No adapters needed.
6. Explosion-proof available
Certified for use in dust/air explosive environments. Flour mills. Grain elevators. Chemical plants.
Where to use it
| Cement plant | Silo level alarm – prevents overflow and empty bins. High-temp option for clinker storage. |
|---|---|
| Grain silo / flour mill | Full level alarm and bin level control. Explosion-proof option for dust-hazard areas. |
| Feed mill | Raw material and finished feed level monitoring. Works with corn, soybean meal, pellets - no recalibration when material changes. |
| Chemical plant | Plastic pellets, fertilizer, powder raw materials. Physical contact sensing - unaffected by dielectric constant changes. |
| Power plant / coal yard | Coal bin level alarm. Explosion-proof and abrasion-resistant options available. |
| Steel mill / foundry | Coke, ore, casting sand level detection. High-temp option up to 1300°C. |
| Food processing | Flour, sugar, starch, milk powder - stainless steel option for food-grade contact. |
HNL40-A Rotary Paddle Level Switch3
For powders. For granules. For bulk solids. For silos, hoppers, and bins.
Simple. Mechanical. Reliable.
Send us your material type, tank height, and mounting thread - we'll recommend the configuration and quote within 24 hours.
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HNL40-A Rotary Level Switch Parameters |
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Specific Parameters |
Value / Description |
|
Measurement Principle |
The HNL40-A rotary paddle level switch uses a low-speed geared motor with a sliding clutch to drive a rotating measuring blade. When the material being measured obstructs the blade's rotation, the motor rotates, activating an internal microswitch and outputting a detection signal. Simultaneously, the motor power is cut off, stopping the supply of power. (Detection state) Once the material being measured is no longer present, the blade, no longer obstructing the movement, resets due to internal spring tension. The detection signal is then switched back, and power is restored to the motor, causing the blade to resume rotation. |
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Product Type |
Standard thread type |
|
Measurement Range |
80~1000mm, 100~1500mm, 100~2000mm, 300~3000mm, 450~6000mm, 100~6000mm, |
|
Output Signal |
NPN, PNP, Relay output |
|
Power Supply |
24VDC (DC), 220VAC (AC) |
|
Process Connection |
Threads, flanges, Customizable |
|
Electrical Connection |
Terminal wiring |
|
Temperature Range |
-20-80°C, -20-350°C, -20-1300°C, -40-350°C, -20-250°C, Customized |
|
Junction Box Material |
luminum alloy with painted finish/PEK/stainless steel |
|
Shell Material |
304 Stainless steel |
|
Protection Level |
IP65 |
|
Protection Level |
Non-explosion-proof type |
|
Certificate |
CE certified |
