KEYENCE FR Series Long Range 2-Wire Explosion-Proof Radar Level Sensor FR-LEX20(L) Instruction Manual

Symbols Used in this Manual

Danger: Indicates instructions that, if not followed, may result in injury or death.

Caution: Indicates instructions that, if not followed, may result in injury or damage to the product or other property.

Note: Highlights important information for deeper understanding or useful knowledge.

Point: Indicates cautions regarding operations that must be performed or operations that are prone to mistakes.

For Your Safety

General Precautions

• Do not use this product for human body protection.
• When using in explosion-proof areas, adhere strictly to the precautions in this manual.
• Ensure no risk of corrosion or damage to equipment before use.
• Do not use in applications where product malfunction could cause serious injury or property damage (e.g., power plants, aviation, railways, vehicles, medical equipment).
• For the FR-SH01(C), avoid applications where leaching is a concern (food, beverages, medical use).
• For the FR-LP(H)20(L) in leaching-concerned applications, use the ferrule attachment tool (OP-88888).
• Failure to use the product according to specifications may compromise its protective functions.
• Conduct a risk assessment for the entire system and ensure appropriate risk reduction measures are in place. Implement protective measures independent of this product for safe operation during abnormalities.
• Verify normal operation and performance before use.
• Take sufficient safety measures to prevent damage in case of product breakdown.
• Clean the sanitary model (FR-LS20(L)) before use.
• Consider potential performance limitations when using with other equipment based on usage conditions and environment.
• When using in acidic/alkaline media, sanitary environments, or for electroplating, check the sensor material's resistance to the media.

Installation Precautions

• Avoid locations with vibrations or shocks exceeding environmental resistance.
• Avoid locations outside the specified ambient temperature range.
• Avoid locations with humidity above 85% RH (no condensation) or rapid temperature changes.
• Avoid locations with volatile flammable substances, solvents, corrosive gases, or strong magnetic/electric fields.
• Noise Resistance:
• Keep power cable length to 20m or less for IO-Link.
• Install the product away from power lines and devices generating strong electric/magnetic fields (solenoids, choppers).
• Route input/output signal lines separately from power and high-voltage lines.
• Use a DC stabilized power supply with an isolation transformer to prevent power supply noise.
• Failure to follow recommended installation conditions may lead to unstable detection.

Regulations and Standards

CE and UKCA Marking

This product complies with EU directives and UK regulations. Operating frequency is 58-63GHz.

• RE Directive (CE) & Radio Equipment Regulations (UKCA): Maximum wireless output varies by model. Manufacturers of machinery incorporating this product must verify the conformity of the entire machinery.
• CSA Certification: Complies with CAN/CSA C22.2 No.61010-1 and UL61010-1. Overvoltage category I, Pollution degree 3 or 4 depending on model. Install at altitudes of 5000m or less and comply with local electrical codes (CEC, NEC). Use CSA/UL Listed Class 2 power supplies.
• Wireless Precautions (60 GHz band): Use in accordance with country/region laws. Interference may occur with devices using the same frequency band (wireless LAN, microwave ovens, etc.), potentially slowing or preventing measurements. If interference occurs, change frequency, stop emitting radio waves, or contact Keyence for solutions. Do not disassemble or modify the unit as it is prohibited by the Radio Law.

Explosion-Proof Precautions

This section details explosion-proof models and associated barriers, including the FR-LEX20(L) radar level sensor, FR-LEXB41 isolation barrier, FR-LEXB42 Zener barrier, FR-LEXB43 Zener barrier with flameproof box and cable gland, FR-LEXB44 Zener barrier with flameproof box, and optional protective cover (FR-LEXP1) and cable gland (OP-88908).

1. Basic Safety Information

1.1 Features and Intended Use

The FR-LEX series radar level sensor measures liquid or powder levels using radar. Models with "EX" are for explosive atmospheres.

• Radar Level Sensor: Consists of a display and sensor unit. The display connects to a barrier for power, and the sensor unit is connected from the bottom.
• Isolation Barrier (FR-LEXB41): Dedicated to FR-LEX series, provides galvanic isolation, requires no earth connection, and has a 4-20 mA signal output. Must be installed in a suitable enclosure.
• Zener Barrier: Dedicated to FR-LEX series, requires an earth connection, and must be installed in a suitable enclosure.
• Zener Barrier with Flameproof Box and Cable Gland (FR-LEXB43): Zener barrier housed in an Ex d/t enclosure with a cable gland.
• Zener Barrier with Flameproof Box (FR-LEXB44): Zener barrier housed in an Ex d/t enclosure with an NPT 1/2 thread for external connection.
• Protective Cover (Optional): Protects the sensor from the external environment.
• Cable Gland (Optional): Used when the display and sensor are installed separately.

1.2 Regulatory and Standards Notices

• CE Marking: Complies with ATEX Directive and RE Directive.
• UKCA Marking: Complies with Equipment and protective systems for use in potentially explosive atmospheres (BS EN Standards) and Radio Equipment Regulations.
• North American Regulations: CSA Certification (UL, FM, CSA standards), FCC and ICES compliance (refer to User's Manual).
• Specific Terms of Use of Certificates: Isolation and Zener barriers are open/associated equipment. Install in suitable enclosures. Minimize risk of electrostatic discharge by controlling ambient humidity and avoiding direct air currents. Metal parts, display screw, and sensor mounting screw are not grounded. Capacitance values are provided.

2 Installation and Maintenance

2.1 General

• Install in accordance with local regulations and laws (e.g., IEC/EN 60079-14, NFPA 70, CSA C22.1, JNIOSH-TR-NO.44).
• Inspect and maintain according to IEC/EN 60079-17.
• Only qualified personnel should perform installation and maintenance.
• Product modification is not permitted.
• Ensure no risk of corrosion or damage before use.
• Ensure no explosive atmosphere and no voltage on the circuit during installation and maintenance.
• Maintain IP ratings for the radar level sensor and Zener barrier with explosion-proof box. Ensure proper closure of openings to prevent dust/water ingress.

2.2 Installation

• External Connections (Cables): Cables used in intrinsically safe circuits must meet barrier parameters. Protect cables against electromagnetic or electrostatic induction using protective conduits or shielded wires.
• Installations spanning different areas (Zones/Divisions) must comply with applicable regulations.
• Zener Barrier with Flameproof Box: Avoid mechanical abrasion of flameproof joints. A cement-fixed explosion-proof seal is required within 50 mm of the conduit entry port. Use the supplied certified Ex d/t cable gland; no other glands are permitted. Ensure the cable entry is securely locked.

2.3 Maintenance

• Regularly inspect for mechanical damage and corrosion.
• Refer to the FR Series User's Manual or contact Keyence for troubleshooting.

3 Repairs

All repairs must be performed by Keyence. Contact your nearest Keyence sales office. Repairs may not be possible for certain models.

Notes on Media and Handling

• Media: If conductive material adheres to the unit's bottom, the measured value may exceed the upper limit. Clean the unit's bottom.
• Handling:
• Metal parts may become hot when detecting high-temperature liquids, posing a burn risk. Do not touch metal parts during operation.
• Threads on the main body are sharp; avoid touching them.
• Avoid use in locations with a risk of static electricity. Use an insulator or a means for continuous static discharge if necessary.

4 Technical Data

4.1.1 IECEx

Details on IECEx certification for Radar Level Sensors (FR-LEX20(L)) and various barriers (FR-LEXB41, FR-LEXB42, FR-LEXB43, FR-LEXB44), including marking, zone classifications, and applicable standards.

4.1.2 ATEX (EU) and UKEX (UK)

Details on ATEX and UKEX certifications for Radar Level Sensors (FR-LEX20(L)) and barriers, including marking, zone classifications, and applicable standards.

4.1.3 NRTL/ACO (North America)

Details on NRTL/ACO certification for Radar Level Sensors (FR-LEX20(L)) and barriers, including zone/division classifications, marking, and applicable standards (UL, CSA, FM).

4.1.4 Type Approval of Electrical Equipment for Use in Explosive Atmospheres (Japan)

Details on Japanese type approval for Radar Level Sensors (FR-LEX20(L)) and barriers, including marking, zone classifications, and applicable standards (JNIOSH).

4.2 Specifications

4.2.1 Electrical Ratings

• Radar Level Sensors (FR-LEX20(L)): Power supply voltage (DC18.3 V to DC35 V), Power consumption (752.5mW), Intrinsically safe circuit parameters (Ui, Ii, Pi, Li, Ci).
• Isolation Barriers (FR-LEXB41): Power supply voltage (DC24V ±25%/-10%), Power consumption (3W), Barrier parameters (Um, Uo, Io, Po).
• Zener Barriers, Explosion-Proof Boxes, and Zener Bars with Cable Glands: Details for FR-LEXB42, FR-LEXB43/LEXB44, including power supply voltage, power consumption, and barrier parameters.

5 Product Overview

System Configuration Example and Part Names

Illustrations and labels for the FR-LEX20 explosion-proof model, FR-LEXB41 Insulation Barrier, FR-LEXB42 Zener Barrier, FR-LEXB43 Zener Barrier (pressure-resistant box with cable gland), and FR-LEXB44 Zener Barrier (pressure-resistant box).

Installation and Mounting

Detailed instructions for various mounting methods:

• Flange Nozzle Installation: Using a gasket and flange mounting fixture.
• Direct Mounting to Top Plate (Mounting Fixture): Using a general-purpose mounting fixture.
• Direct Mounting to Top Plate (Screw Mounting): Using a G1-1/2 screw hole.
• Direct Mounting to Top Plate (Nut Mounting): Using a ∅49 hole and nuts.
• Mounting on Inner Wall: Using a side mounting bracket.
• Ferrule Installation: Using ferrule attachment tools and gaskets.

Recommended Installation Conditions: Ensure no metal obstacles within the detection range. Adjustment function may be needed if conditions are not met.

Adjusting Installation Direction: The housing can be rotated approximately 340°.

6 Wiring

Preparing the Cables

Recommended cable specifications (AWG12~26 for power, AWG16~26 for separate cables). Use shielded power cables.

How to Process Cable Ends

Instructions for stripping insulation and using ferrule terminals for power and separate cables.

Wiring

• Integrated Unit: Wiring instructions for the display unit and sensor head.
• Separate Display: Instructions for separating the display unit and wiring it.
• Wiring to External Devices: Diagrams and terminal connections for using an insulation barrier (FR-LEXB41) and Zener barriers (FR-LEXB42, FR-LEXB43/LEXB44) with external devices. Includes terminal block wiring details and recommended tightening torques.
• Ground Wire Wiring: Instructions for connecting ground wires using ring terminals, with specifications for terminal dimensions and earth wire resistance.

7 Initial Settings at First Startup

Guide to initial settings using the keys:

• Input/Output Settings: PNP/NPN selection.
• Language: Selectable languages include English, Japanese, Chinese, and German.
• Detection Target: Select based on the dielectric constant of the measurement target (Water-soluble liquid, Oily liquid, Powder). Incorrect selection may lead to inaccurate detection.
• Indicator Pattern: Selectable lighting patterns for the ring indicator.
• Distance to Bottom: Enter the distance from the sensor's reference surface to the tank's bottom (zero point).
• Distance to Top Surface: Enter the distance from the sensor's reference surface to the tank's top surface (100% point).
• Display Value Scaling: OFF (display height) or ON (scaled to volume/mass using tank shape or multi-point correction).
• Tank Shape: Options include Straight, Spherical, Cylindrical (horizontal), Conical bottom, Square pyramid bottom, Sloped bottom, and Multi-point compensation.
• Indicator Light Setting Values: Set values for indicator lights, with options for level-linked patterns or custom settings.

8 Adjustment Function

Recommended for stable detection after initial settings. Access via the menu screen.

9 Initialize Settings

Option to reset settings to factory defaults via the menu.

10 Maintenance

Clean any deposits or foreign matter from the mounting bracket, sensor body, or sensor head bottom as needed.

11 Warranty Information

• Applicable Products: Products manufactured and sold by Keyence. Consumables like relays and batteries are not covered.
• Warranty Period: One year after delivery.
• Warranty Coverage: Free replacement for failures attributable to Keyence within the warranty period. Exclusions include improper external conditions, environment, handling, usage, issues caused by other equipment, unauthorized modifications, failure to perform maintenance, unforeseen failures, and external factors (disasters, voltage abnormalities). Secondary damages are not covered.
• Applications: Products are designed for general industry. Not intended for uses with expected huge impacts on human life and property (nuclear power plants, aviation, railways, vehicles, medical equipment, public utilities). Consult Keyence for specific applications requiring high safety considerations.

Contact Information

• Phone: 0120-663-000 (connects to nearest sales office; not available from some IP phones)
• Information Service: www.keyence.co.jp (download catalogs, manuals, CAD data)
• Export Document Service: www.keyence.co.jp/yushutsu (download export documents)

KEYENCE CORPORATION
Sensor Division
1-3-14 Higashi-nakajima, Higashiyodogawa-ku, Osaka 533-8555

Specifications are subject to change without notice. Company and product names are trademarks of their respective companies.