LiftMaster 50-HERK2 Motion Detector
The LiftMaster 50-HERK2 motion detector is a commercial door activation sensor designed to detect moving traffic approaching or leaving a door opening. It uses microwave sensing to help separate intended traffic from unwanted cross traffic when the detector is installed and adjusted correctly.
This unit is commonly used on industrial overhead doors, warehouse doors, loading areas, and commercial service doors where hands-free activation is preferred. The sensor can help improve traffic flow, but it must be wired and programmed to the correct operator input for the job.
Compatibility and Application Notes
- Commonly used with LiftMaster commercial door operators that accept an external activation device.
- Often associated with Logic 5.0 commercial door operator installations when a motion activation sensor is required.
- May be used on commercial and industrial door openings where the mounting height, angle, and control wiring match the sensor requirements.
- Not a monitored entrapment protection device and should not replace required safety photo eyes, sensing edges, or other UL 325 safety devices.
- Use the installation manual and operator wiring diagram to confirm power, relay output, mounting location, and activation function.
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Microwave motion detector / activation sensor |
| Part Number | 50-HERK2 |
| Application | Commercial and industrial door activation |
| Detection Type | Vehicle and/or pedestrian movement, depending on setup |
| Maximum Detection Field | Up to approximately 20 ft. x 16 ft. when installed within rated limits |
| Maximum Mounting Height | Up to approximately 23 ft. |
| Mounting Angle | Up to approximately 45 degrees |
| Function | Detects movement toward or away from the door and can help limit unwanted cross-traffic activation |
| Notes | Activation device only; safety devices are still required where applicable |
Also Known As / Related Part Numbers
- 50-HERK2
- 50 HERK2
- HERK2
- Herkules 2 motion detector
- 50-HERK-RC2 programming remote, sold separately when available
Technician Note
Set the detection field after the sensor is physically mounted. A motion detector aimed too wide, too low, or toward cross traffic can cause unwanted openings or missed activation.
Before Ordering
- Confirm the operator has the correct activation input for the detector output.
- Confirm the mounting height and angle are suitable for the opening.
- Confirm whether the site needs vehicle-only, pedestrian-only, or mixed traffic detection.
- Confirm required monitored entrapment protection is already installed and working.
- Confirm whether a programming remote or manual adjustment access is needed for setup.
Professional Advisory
Commercial door activation wiring and sensor aiming should be handled by a qualified door technician when the operator wiring, safety circuit, or door behavior is uncertain. Do not use an activation sensor to bypass required safety devices.
Product Questions & Answers
Is the 50-HERK2 a safety photo eye?
No. The 50-HERK2 is a motion activation detector. It is not a substitute for monitored safety photo eyes, sensing edges, or other required entrapment protection devices.
Where is this motion detector normally mounted?
It is normally mounted above or near the door opening where it can monitor traffic moving toward or away from the door within the rated mounting height and field size.
Can it ignore cross traffic?
The 50-HERK2 has cross-traffic optimization features, but performance depends on proper mounting, aiming, and programming for the specific site.
Will this work on every LiftMaster commercial operator?
It may be used with commercial operators that provide a compatible activation input and power arrangement. The operator wiring diagram should be checked before installation.
Why would a door open when no vehicle is entering?
Unwanted openings can come from an overly wide detection field, cross traffic, vibration, incorrect sensitivity, or a mounting angle that does not match the traffic pattern.
