Model #



Infrared/Infrared over height vehicle detection system with auto ranging power supply designed to continue operation in the occurrence of solar rejection, when detection would normally be interfered with by direct light entering the sensor eye during sunrise and sunset. Designed with the ability to run in parallel with 3401-Z.

The Over Height Vehicle Detection System (OHVDS) Model 3402-Z consists of two narrow beam infrared/infrared source and detector pairs, auto ranging power supply, control electronics and is designed to operate in parallel with Model 3401-Z. The two source eyes transmit the beams in parallel but opposite in direction. This feature allows for single-beam operation in the event of sun blinding in one of the detectors.

The source and detector pair is contained in two separate housings. The housings can be mounted via support pole structures using either one or a combination of mounting brackets that allow for height adjustments, three-axis mounts that provides for adjustment in three planes or pole caps.

Under normal operation, the Over Height Vehicle Detection System (OHVDS) is configured for dual beam operation. In this configuration, directional discrimination is selectable through a switch and is set according to the direction of traffic. When the beams are broken in the proper sequence, the system will provide relay closures to connected warning devices, indicating overheight detection. The Over Height Vehicle Detection System (OHVDS) also feeds a continuous status signal (Fault) to connected controls to indicate that the OHVDS is functioning normally.

In the case where one of the sources or detectors fails or is in a sun blinding condition, the OHVDS falls back to a single beam operation.

In the case where both beams have been compromised (blocked, fail, or loss of power to either Master or Remote), the OHVDS enters a fault condition by opening the fault relay contact, which is normally held closed, breaking the continuous signal to the LFC.

Infrared LED / Infrared LED
Paired with 3401-Z


  • Input Power: 115 VAC, +/- 10%, 50/60 Hz. Other options include 240 VAC, +/10%, 50/60 Hz operation.
  • Output: Two Form C, dry relay contact closures for Over-height Alarm Functions. One Form C, dry relay contact opening for Fault Reporting. Contacts rated 240 VAC 10A, protected by 8A circuit breakers.
  • Certifications: CE Marking.
  • Fault Reporting: Factory configuration per customer selection of operational mode, loss of source/ detector/power or total failure. See Options and Accessories section.
  • Alarm Time: Adjustable by customer from 2 to 60 seconds.
  • Electronics: Sensors are NEMA 6P enclosure rated.
  • Effect of Ambient Light: Use of Dual Beam IR/IR Z-Pattern® provides automatic switch to Single Beam Detection Mode of Over-height Protection if the sun or other interference saturates one detector.
  • Maximum Range: 700 feet (213 m). Suggested maximum range 200 feet (61 m) to allow for bad weather and lens contamination.
  • Direction Selection: Selection switch. No tools or adjustment required.
  • Alignment: Four LEDs and meter (GO-NOGO functions) provided for ease of alignment and testing.
  • Reaction Speed: 1 to 75 MPH (1 to 121 km/h) for a 2.5 inch (6.25 cm) diameter object 1 inch (2.5 cm) above the detection height. Custom speed/size available.
  • Temperature Range: -40° to +135° F (-40° to +57° C).
  • Environmental Control: Internal thermostat with heater and fan controls air flow which reduces moisture and maintains internal temperature during cold weather.
  • Housings: External housing is heavy ALMAG casting and sheet aluminum (not less than 1/8 inch or .318 cm thickness) for rugged durability and extended life. Cabinet design minimizes effects of vandalism and provides rigid mounting. NEMA 3R Certified.
  • Mounting: The pole cap serves as a mounting bracket and sighting base with our poles, or a three-Axis mount is available. See Options and Accessories section.
  • Dimensions: Remote Cabinet: 12¾ x 16½ x 8½ inches (32 x 42 x 22 cm). Master Cabinet: 12¾ x 18¾ x 8½ inches (32 x 48 x 22 cm).
  • Shipping Weight: 60 lbs (27 kg).


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