The E3JK-R4M1 is an industrial retro-reflective photoelectric sensor engineered for non-contact object detection in automation and control systems. Featuring an integrated transmitter and receiver within a single housing, it projects an optical beam toward a dedicated corner-cube reflector plate. When an passing object breaks the reflected light path, the sensor actuates an internal SPDT electromechanical relay. With a detection range of up to 4 meters, selectable Light-ON/Dark-ON operation, and dry relay contacts, it directly drives alarms, contactors, indicators, and PLC inputs without external interface circuits.

Specifications

• Model: E3JK-R4M1
• Sensor Type: Retro-reflective photoelectric sensor (Transmitter and receiver in one unit)
• Sensing Distance: 0.1 to 4 meters (With included reflector)
• Light Source: Infrared / Red LED (~660 nm)
• Operating Voltage: 12V to 24V DC (Supports standard industrial 12-24V supplies; wide-voltage models accept 90-250V AC/DC)
• Output Type: Relay contact SPDT (1 NO + 1 NC, dry contacts)
• Relay Contact Rating: 3A 250V AC / 3A 30V DC resistive load
• Response Time: <= 30ms
• Directional Angle: Sensor 1° to 5°, Reflector >= 40°
• Protection Rating: IP65 (Dust and water-splash resistant)
• Operating Temperature: -25°C to +55°C
• Housing Material: Flame-retardant ABS plastic
• Dimensions: 50mm x 50mm x 20mm
• Cable Length: ~1.2 meters multi-core industrial lead
• Included Hardware: Prismatic reflector panel and steel mounting bracket

Wiring and Interface Guide

• Brown: Power Supply Input (+12V to +24V DC or AC Line depending on model label)
• Blue: Power Supply Common (0V / GND or AC Neutral)
• White: Relay Common Contact (COM)
• Black: Relay Normally Open Contact (NO) - Closes when triggered
• Gray: Relay Normally Closed Contact (NC) - Opens when triggered

Key Features

• Single-Unit Wiring: Houses both emitter and detector optics in one body, eliminating the need to run electrical wiring to the opposite side of the detection zone.
• Isolated SPDT Dry Relay Output: Onboard mechanical relay provides galvanic isolation, allowing direct switching of AC or DC loads without external interposing relays or transistors.
• Sensitivity & Mode Adjustment: Equipped with a rear sensitivity adjustment potentiometer to tune detection thresholds for transparent, glossy, or small items.
• Light-ON / Dark-ON Selectable: Configurable operating mode allows output triggering upon beam restoration (Light-ON) or beam interruption (Dark-ON).
• High Ambient Noise Rejection: Optical filtering prevents false tripping from factory ambient light, overhead fluorescent fixtures, and sunlight.

Common Applications

• Conveyor Sorting & Counting: Sensing cartons, tote boxes, and opaque packaging on assembly lines.
• Automatic Doors & Overhead Gates: Detecting vehicles or pedestrians to prevent premature closure.
• Machinery Interlocks & Travel Limits: Monitoring safe clearance zones and end-of-stroke positions for heavy automation equipment.
• Palletizing & Warehouse Racks: Verifying pallet placement and clearance on automated storage and retrieval systems (ASRS).

Usage Tips

• Reflective Material Interference: Shiny surfaces (such as mirror-finish steel or shrink-wrap) can bounce light directly back into the sensor, mimicking the reflector. If false non-detection occurs, tilt the sensor axis 10° to 20° relative to the passing object's face.
• Optical Alignment: Fasten the sensor securely to its bracket, then aim the beam at the reflector until the red operation indicator LED changes state reliably. Secure the reflector firmly to withstand conveyor and machine vibrations.
• Inductive Load Suppression: When using the internal relay contacts to switch inductive loads (such as AC contactors, magnetic clutches, or solenoid valves), install an RC snubber across AC contacts or a flyback diode across DC coils to prevent contact arcing and pitting.