Rotary Level Indicator - Model KA
(Paddle ordered separately)


Self-Validating Eliminates Costs Associated With Unexpected Sensor Failures
Industry-First Magnetic Sensing Technology (Patented)
Monitor Sensor Health, Not Just System Power Failure - "Fail-Safe" PLUS
Twist On/Off Cover - No More Bolts!
Wiring Access - 2 Conduit Entrances
Motor Shuts Off When Paddle is Impeded to Significantly Extend Motor Life and Reduce Maintenance Costs
Local Status Indicating Light On Most Models
Standard SafePoint Level Switch Rated to +250°F (+121°C)
Hi-Temp SafePoint Level Switch Rated to +750°F (+399°C)
Hazardous Location Approval Available
Unique Low Voltage DC Design Available - Click to view Technical Sheet (PDF)

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Safepoint® Rotary Paddle Level Switch

Bulletin Button

Product Overview



Principle of Operation

Available Configurations





Similar Item(s):

Rotary Level Indicator - Model KA

Model KA / KAX Rotary Paddle Level Indicator



The SafePoint® self-validating fail-safe bin level indicator from Monitor is the state-of-the-art in rotary paddle technology. Going beyond traditional fail-safe sensor technology that only protects against power failure, the SafePoint bin monitor is the most reliable, rotary paddle point level control sensor available. Ideal as a high level indicator for silo / bin overfil protection.

The SafePoint bin level switch provides the ultimate in performance wherever critical continuous operation must be ensured. Detection of both material presence and its own operational status is performed on a continuous basis.

The SafePoint level sensor monitors its electrical and mechanical operating condition. This, in conjunction with separate outputs for material sense and unit status (fault conditions) make the SafePoint a "truly" fail-safe, self-validating device.

Imagine a bin level switch that is more than just an indicator of the presence or absence of material. Picture technology that allows intelligent devices to indicate when something is wrong. Dream that a level sensor provides real-time information when the quality of the sensor function no longer allows it to operate as you expect. That is a “self-validating” bin level indicator. Now you can wake up, your dream has arrived. Costly overfilling and outages due to sensor failure can now be avoided!

Principle of Operation

While the SafePoint level switch is an evolution in rotary paddle technology, it continues to use tried-and-true operating techniques. Unlike many other available units, the SafePoint incorporates a feature that automatically shuts off its motor when the paddle is in a stalled condition. This extends the life of the unit and minimizes maintenance.

The operation of the SafePoint® rotary paddle bin monitor uses patented technology to detect material presence and operational status of the unit. The unit is installed through the wall of the vessel so that the paddle protrudes inside the vessel. A small electric motor drives the paddle, which rotates freely in the absence of material.

The rotation of the unit’s shaft is continuously monitored by detection of a magnetized rotating disk. When the paddle is impeded by material, the shaft rotation stops. The motor rotates within the housing and magnetized sections of the motor mounting plate are detected. Use of these patented magnetic sensing techniques eliminates problems that occur with fouling of the optical systems used by other brands.

The built-in microcontroller performs self-validating diagnostics and monitors both shaft and motor mounting plate rotation. This allows the SafePoint to easily distinguish between material presence and any electrical and mechanical failure of the unit. When material presence is detected, the SENSE relay changes state and the drive motor is de-energized to extend motor life. This output is available to control a process function or alarm circuit. When the material level drops, a tension spring returns the drive motor to its original running condition and is reactivated.

A unit failure is detected by sensing a lack of shaft rotation while material presence has not been detected by rotation of the motor mounting plate. In a failure condition the independent FAULT relay will change state. Monitoring the state of both the SENSE and FAULT relays provides the most flexibility for control and monitoring that is beyond being just “fail-safe”.


The rugged and reliable fail-safe design of the SafePoint® bin monitor makes it the best choice for critical level control applications. The unit is compatible with many granular, pelletized and powder bulk applications. It can be utilized for high level indication of materials over 10 lb/ft³ (160 kg/m³ ) and for low and intermediate level indication for materials over 5 lb/ft³ (80 kg/m³ ). The SafePoint bin level monitor can be installed almost anywhere dry bulk materials are stored including bins, hoppers, silos and tanks.

Typical Applications include, but are not limited to:


Silica Sand




Calcium Dust











Foundry Sand

Pre-Mix Ingredients






Self-validating operation monitors electrical and mechanical status for critical applications - beyond "fail-safe"

(1) Use of magnetic sensing technology ensures reliable operation even in dusty environments

(2) Twist on/off cover for convenient and easy access - No bolts to lose or hold

(3) 1-1/4” NPT or 1-1/2” BSPT process connections

(4) Two conduit connections provide easy wiring access

(5) Microcontroller-based electronics ensures consistent and reliable operation

(6) Independent SPDT relays for material sense and fault outputs

(7) Local Indication (ordinary locations only) of operating status

(8) Cast aluminum housing with rugged powder coat finish

High Temperature version available (up to 750°F/399°C)



Cut Away View of Level Switch


Available Configurations

The SafePoint® fail-safe rotary paddle bin monitor is available in configurations to serve 115VAC, 230VAC and 24VAC/DC power requirements.

The SafePoint bin monitor incorporates a red and green LED to indicate material sense and unit status. A red LED illuminates when material presence is detected. A green LED illuminates when material is not present. The green LED will flash during initialization immediately following power-up. The red LED will flash during a failure mode. This indication can be viewed without removing the cover (units supplied for general purpose ordinary electrical locations only).

The SafePoint bin monitors are available approved to CSA (CSA(US/C) for North American use) and ATEX/IECex requirements. Approvals for either general purpose, dust-ignition-proof and/or explosion-proof hazardous area locations can be provided. All units carry the CE mark. Refer to "Specifications" for details.

The SafePoint high temperature model incorporates all the standard features of the SafePoint bin monitor, but can be used in applications where internal bin temperatures reach as high as 750°F (399°C). The hi-temp models incorporate a specially designed mounting plate, pipe extension with air purge connection (recommended for all high temperature applications; must be used for 500°F/260°C), shaft extension, couplings and bushings. The high-temp assembly is available in either a carbon steel or stainless steel version.



Monitor offers a variety of interchangeable paddle assemblies to meet the needs of a wide variety of applications. Different material densities, particle sizes and flow characteristics require specific paddles to provide optimum performance. View Paddle Assembly Selection Guide (PDF).

Dimensions are shown in inches with millimeter equivalent in brackets.

1.) Standard Stainless Steel Three Vane Paddle: The most popular of all paddles. For use with average weight materials.
P/N 1-4146

Three Vane Level Paddle

2.) Large Stainless Steel Three Vane Paddle: Provides accurate level control for lightweight materials. P/N 1-4141

Large 3 Vane Paddle

3.) Insertable* Stainless Steel, Two Vane Collapsible Paddle: Provides low and high level control for light to average weight materials.
P/N 1-4161
Click Here For Product Sheet

2 Vane Collapsible Paddle

4.) Insertable* Stainless Steel, Scimitar Single Vane Paddle: Provides low and high level control for light to average weight materials.
P/N 1-4193

Insertable Level Paddle

5.) Insertable*, Stainless Steel Single Vane Paddle: Provides low level control for average weight materials and low to high level control for heavy materials under 1-1/2 inch (40 mm) in diameter. P/N 1-4145

Single Vane Paddle

6.) Stainless Steel, Two Vane Paddle: Provides low and high level control for heavy materials under 1-1/2 inch (40 mm) in diameter. P/N 1-4135

Two Vane Paddle

7.) Stainless Steel Four Vane Paddle: For use with average to heavy weight materials in low and high level control installations.
P/N 1-4156

Four Vane Paddle

8.) Stainless Steel Triangular Arc Single Vane Paddle: Provides low and high level control for light to average weight materials. P/N 1-4144

Triangle Arc Paddle

9.) Ex-Flex Three-Ply 20 inch (508 mm) Belt Paddle: Provides low and high level control for heavy materials over 2 inch (50 mm) in diameter. Top mount only. P/N 1-4137

Flexible Level Paddle

*Insertable paddles eliminate the need for a mounting plate. P/N 1-4161 and 1-4193 are insertable through either a half or full 1-1/4” or 1-1/2” coupling, that is welded to the bin wall. P/N 1-4145 is insertable through a half 1-1/4” or 1-1/2” coupling.

The flexible coupling works to absorb heavy loads, side loads and loads caused by product surges, thus protecting the internal workings and extending the life of the paddle unit. A flexible coupling should be used with heavy materials and in top mount installations where a solid shaft extension is used. Monitor offers the following coupling option:
Spring-Flex: P/N 1-3335

Mounting plates allow the paddle units to be mounted from the outside of a vessel to curved or flat surfaces. All mounting plates featured below mount via six bolts.

1.) Half Coupling Mounting Plate: For use in side mount installations. Available in powder coated carbon steel for general purpose applications and stainless steel for use in corrosive environments. Stainless Steel Plate: P/N 1-0112. Carbon Steel Plate: P/N 1-0101 for 1-1/4” NPT connection and P/N 1-0100 for 1-1/2” BSPT connection.

2.) Full Coupling Mounting Plate: For use in top mount installations where a shaft extension and shaft guards are required. Available in powder coated carbon steel for general purpose applications and stainless steel for use in corrosive environments. Stainless Steel Plate: P/N 1-0113. Carbon Steel Plate: P/N 1-0102 for 1-1/4" NPT connection and P/N 1-0115 for 1-1/2" BSPT connection.

3.) K-Flange Aluminum Mounting Plate: For flat surfaces or thin walled vessels where extra strength is required. Ideal for semi-corrosive environments, including out doors. P/N 1-3316.

Dimensions are shown in inches with millimeter equivalent in brackets.
Mounting Plate

SHAFT EXTENSIONSFlexible Cable Extension
Many top mount installations require that the paddle extends into the vessel to a predetermined level. Solid shaft extensions are available in a variety of lengths up to 144 inches (3.6 m) to meet these demands. A flexible cable extension is also available. This 6.5 foot (2.0 m) flexible extension can be easily shortened in the field by the user. The use of the flexible cable extension for lengths greater than 3 feet (0.9m) requires the use of a guard to ensure proper activation of the rotary paddle bin monitor.

Shaft guards are recommended for use with solid shaft extensions to limit the movement caused by side loading that would otherwise damage the working components of the paddle unit. Shaft guards should be the same length as the extension and should always be used when the extension meets or exceeds 18 inches (460 mm) in length.




Power Requirements:

115 VAC (+/- 10%); 9 VA; 50/60 Hz
230 VAC (+/- 10%); 9 VA; 50/60 Hz
24 VAC/DC (+/- 15%); 11 VA


6562 ft (2000 m) max

Relative Humidity:

Suitable for outdoors

Installation Category:


Pollution Degree:

4 (Reduced to 2 via enclosure)

Ambient Operating Temp:

-40°F (-40°C) to +150°F (65°C)

Internal Bin Temp:



Std. Unit:

to +250°F (+121°C)


Hi-Temp Unit:

to +750°F (+399°C)

Conduit Connection:

Two(2) 3/4” NPT; M20 cable glands (Ordinary Location units with 1-1/2” BSPT process connection only; Not provided on Haz Loc units)




Material Sense:

One SPDT; 5A @ 250 VAC, 30 VDC max


Unit Status (Fault):

One SPDT; 5A @ 250 VAC, 30 VDC max

Maximum Pressure:

30 PSI (2 bar)


5 lb/ft³ (80 kg/m³ ) minimum material density (when using large 3-vane paddle)


Red and green high intensity LEDs indicate material sense and unit status conditions (Ordinary Location unit only)


Die cast alum., NEMA 4 / ENCLOSURE TYPE 4, IP66

Housing Finish:

Powder coating

Mounting Connection:

1-1/4" NPT or R 1-1/2 (BSPT 1-1/2)

Shipping Weight:

Approx. 8 lbs (3.63 kg)

Materials of construction/accessories:

Flexible Couplings: 304 stainless steel

Mounting Plates: Carbon steel or 304 stainless steel

All Paddles except Ex-Flex: 304 SS

Ex-Flex Belt: 304 SS coupling, rubber/fabric blend belt

Flexible Cable Extension: 304 SS 1/4” diameter

Shaft Seal: Nitrile


CSA(US/C): Ordinary Locations; Class I, Div. 1&2, Groups C, D; Class II, Div. 1&2,

(Ex) II 1/2 D c T 85°C
ExtD A20/A21 T 85°C
(Ta -40°C to +65°C)

DIP A21 IP6X TA 100°C
-40°C to +65°C

CE Mark



Monitor Technologies LLC warrants each SafePoint® rotary paddle bin indicator it manufactures to be free from defects in material and workmanship under normal use and service within two (2) years from the date of purchase. The purchaser must give notice of any defect to Monitor within the warranty period, return the product intact and prepay transportation charges. The obligation of Monitor Technologies LLC under this warranty is limited to repair or replacement at its factory. This warranty shall not apply to any product which is repaired or altered outside of the Monitor Technologies LLC factory, or which has been subject to misuse, negligence, accident, incorrect wiring by others or improper installation. Monitor Technologies LLC reserves the right to change the design and/or specifications without prior notice.

Part Numbers / Product Configurations

Part # > Product Configuration

1-8511-1 > SAFEPOINT,115VAC,1-1/4,O/L
1-8511-11 > SAFEPOINT,115VAC,HT-CS,O/L
1-8511-12 > SAFEPOINT,115VAC,HT-SS,O/L
1-8511-2 > SAFEPOINT,115VAC,1-1/4,H/L
1-8511-21 > SAFEPOINT,115VAC,HT-CS,H/L
1-8511-22 > SAFEPOINT,115VAC,HT-SS,H/L
1-8511-3 > SAFEPOINT,115VAC,1-1/4,ATEX/IECex
1-8512-1 > SAFEPOINT,115VAC,1-1/2,O/L
1-8512-3 > SAFEPOINT,115VAC,1-1/2,ATEX/IECex
1-8521-1 > SAFEPOINT,230VAC,1-1/4,O/L
1-8521-11 > SAFEPOINT,230VAC,HT-CS,O/L
1-8521-12 > SAFEPOINT,230VAC,HT-SS,O/L
1-8521-2 > SAFEPOINT,230VAC,1-1/4,H/L
1-8521-21 > SAFEPOINT,230VAC,HT-CS,H/L
1-8521-22 > SAFEPOINT,230VAC,HT-SS,H/L
1-8521-3 > SAFEPOINT,230VAC,1-1/4,ATEX/IECex
1-8522-1 > SAFEPOINT,230VAC,1-1/2,O/L
1-8522-3 > SAFEPOINT,230VAC,1-1/2,ATEX/IECex
1-8531-1 > SAFEPOINT,24VDC/AC,1-1/4,O/L
1-8531-11 > SAFEPOINT,24VDC/AC,HT-CS,O/L
1-8531-12 > SAFEPOINT,24VDC/AC,HT-SS,O/L
1-8531-2 > SAFEPOINT,24VDC/AC,1-1/4,H/L
1-8531-21 > SAFEPOINT,24VDC/AC,HT-CS,H/L
1-8531-22 > SAFEPOINT,24VDC/AC,HT-SS,H/L
1-8531-3 > SAFEPOINT,24VDC/AC,1-1/4,ATEX/IECex
1-8532-1 > SAFEPOINT,24VDC/AC,1-1/2,O/L
1-8532-3 > SAFEPOINT,24VDC/AC,1-1/2,ATEX/IECex


Last Rev.: May 21, 2021