BEA 10MS31J-B Microwave Touchless Actuator, Jamb Plate - Black

The BEA 10MS31J-B is a microwave touchless actuator from BEA's MAGIC SWITCH family - jamb plate mount, black finish, adjustable detection zone 4 to 24 inches, relay hold time 0.5 to 30 seconds, ANSI 156.10 knowing act compliant, IP54 rated, 12-24 VAC/DC. If you searched "ms31", "bea ms31", or "picture?" - this is the product, with a full visual and functional description below.

"Picture?": What the BEA 10MS31J-B Looks Like

If you searched "picture?" or landed on this page and couldn't identify the product from the listing - the BEA 10MS31J-B is a flat rectangular jamb plate actuator that mounts vertically on a door jamb or wall surface. In black finish, it has a slim, low-profile black housing with a hand and wave graphic (text and hand logo) indicating the wave-to-open gesture zone. The plate is sized to mount on a standard door jamb without protruding significantly from the wall face. A small LED indicator is visible on the face - its lit state (on in detection or on when not in detection) is configurable by dipswitch.

When installed, it looks like a slim black panel mounted beside the door. There is no visible switch, button, or moving part - it is completely touch-free. You wave your hand within 4 to 24 inches of the face and the door operator activates.

What the MS31 Is: Microwave Touchless Actuator Explained

A touchless actuator replaces the push plate beside an automatic door. Instead of physically pressing a button to open an automatic door, the user waves their hand in front of the sensor. The MS31 detects the hand movement using microwave technology and sends a relay signal to the door operator - triggering the door to open exactly as if a push plate had been pressed.

The MS31 is specified for any automatic door application where eliminating physical contact is the goal: reducing pathogen transmission, improving access for mobility-impaired users, and meeting ADA and ANSI access compliance requirements.

Microwave vs Infrared: Why BEA Uses Microwave Technology

Every competitor's page lists "microwave motion technology" without explaining why microwave is the correct technology for a door actuator. Here is why:

Infrared (PIR) sensors detect heat differential - a warm hand moving against a cooler background. They are affected by ambient temperature changes, direct sunlight, HVAC airflow, and any environmental factor that changes the thermal background. In a vestibule entry with exterior temperature bleeding in, or in a food service facility near cooking equipment, PIR sensors produce false triggers from temperature changes rather than actual hand detection.

Microwave sensors emit a continuous low-power microwave field and detect the Doppler shift caused by movement within that field. Temperature, lighting, and ambient conditions do not affect operation. The sensor responds to physical motion - a hand, a cart, a wheelchair - not to thermal changes. This produces consistent, dependable activation regardless of environmental conditions.

For hospital entries, pharmacy access points, clean rooms, and food service facilities where false triggers or missed triggers both create operational problems, microwave is the correct technology.

ANSI 156.10 Knowing Act Standard: What This Compliance Means

The ANSI 156.10 knowing act standard governs touchless actuators for low-energy automatic doors. "Knowing act" means the user must perform an intentional action to trigger door opening - the activation should not happen from incidental or unintentional movement. The MS31 is adjustable from 4 to 24 inches precisely to allow compliance with this standard by setting the detection range short enough that only a deliberate wave-in-close movement triggers activation, rather than someone simply walking past the door.

For applications where ANSI 156.10 compliance is required by the building code or the ADA consultant's specification, the MS31's adjustable detection zone and relay hold time allow the integrator to configure the unit to the exact compliance parameters.

Timed vs Toggle Output: The Two Relay Modes

No competitor page explains the difference between the two output modes on the MS31. This is a critical programming decision:

Timed (pulse) output: The relay closes for a configured time period (0.5 to 30 seconds, adjustable by dipswitch) and then releases regardless of whether the hand is still in the detection zone. Correct for door operator applications where the operator needs a momentary trigger signal - the relay pulse triggers the operator, the operator takes over, and the relay resets. This is the standard mode for most door operator integrations.

Toggle output: The relay state changes each time a detection event occurs - first wave closes the relay, next wave opens it. Correct for door hold-open applications or lighting control where a sustained on/off state is required.

Behind-Drywall Mounting: The Hidden Sensor Option

The MS31 microwave sensor can be installed behind non-metallic surfaces - mounted behind drywall, for example - with only the decorative jamb plate visible on the surface. The microwave field penetrates drywall, wood, and other non-metallic materials. This allows completely hidden sensor installation for architectural applications where no visible sensor element is acceptable. The plate provides the visual cue for the user while the sensor operates behind the wall.

Metal surfaces block microwave - do not mount behind metal panels, metal-face composites, or metal studs without fiberglass blocking.

4-Wire Connection: What Each Wire Does

The 10MS31J jamb plate kit uses four wires: two power wires (red = positive power, black = negative power) connecting to the 12-24 VAC/DC power supply, and two relay output wires connecting to the door operator's activation input. For new construction with a full door operator wiring run, all four wires are used. The power supply can be the door operator's auxiliary power output or a dedicated low-voltage supply.

Relay specifications: Maximum contact voltage 60VDC / 125VAC. Maximum contact current 1 amp (resistive). Maximum switching power 30W DC / 60 VA AC.

IP54 Rating: Outdoor and Cleaning-Chemical Resistance

IP54 - protection against dust ingress (partial) and water splash from any direction. The IP54 rating means the 10MS31J-B can be installed in covered exterior vestibule locations and withstands daily cleaning with water spray and standard commercial cleaning products. The foam gasket on the jamb plate provides additional sealing at the wall mounting surface.

MS31 Variant Matrix: J, R, U - Color Suffixes

10MS31J (jamb plate kit - this listing): Mounts on door jamb or narrow wall surface. Ships with sensor, jamb plate, and base plate. Surface mount only - requires surface mount box 10BOXJAMBST. Available in Black (B), White (W), and Gray (G).

10MS31R (round plate): Round plate format for post or pillar mounting.

10MS31U (single/double gang plate): Fits standard single-gang and double-gang electrical box openings for flush-mount wall installations.

Retrofit push plate replacement: The 10MS31J can replace an existing push plate when used with the 10RD900 900MHz receiver and 10TD900TR 900MHz retrofit transmitter - no new wiring run required.

Specifications

Model: BEA 10MS31J-B

Series: MAGIC SWITCH MS31

Type: Microwave touchless actuator, jamb plate mount

Finish: Black (B); also White (W) and Gray (G)

Detection Technology: Microwave (Doppler)

Detection Range: 4 to 24 inches (adjustable)

Relay Output Modes: Timed (0.5 to 30 seconds, adjustable) or Toggle

LED Setting: Dipswitch configurable - lit in detection or lit when not in detection

Silent Operation: Yes - no audible click or tone

IP Rating: IP54 - dust and water splash resistant

Power: 12 to 24 VAC/DC

Relay Contact Voltage: 60VDC / 125VAC max

Relay Contact Current: 1A max (resistive)

Relay Switching Power: 30W DC / 60 VA AC

Wiring: 4-wire (2 power, 2 relay output)

Hidden Mounting: Behind non-metallic surfaces (drywall, wood)

Surface Mount Box: 10BOXJAMBST required (sold separately)

ANSI Compliance: 156.10 knowing act adjustable

Applications: Full energy swing doors, low energy swing doors, industrial doors

Kit Contents: Sensor, jamb plate, base plate

American Locksets has stocked BEA touchless actuators since 2001.