Reno A&E B-4 12V to 24V 11-Pin Single Channel Loop Detector Fail Secure
The Reno A&E B-4 is the low-voltage 11-pin version of the Reno Model B single-channel vehicle detector. It is used in gate operators, barrier gate cabinets, parking equipment, card access lanes, and other vehicle control systems where one inductive loop needs to provide relay signaling to the controller. The B Series is an older but well-known Reno platform with internal DIP switch setup and dual relay outputs, giving it more output flexibility than a very basic single-output detector. The B-4 should be matched to the original B-4 label, low-voltage power source, 11-pin Amphenol-style harness, and fail-safe or fail-secure configuration. Many older B Series installations are serviced today with BX Series detectors, but the replacement must be selected by voltage, output behavior, socket wiring, and site requirements rather than by appearance alone.
Compatible With
- Older Reno A&E Model B installations calling for B-4, B4, or low-voltage 11-pin Model B detector.
- Select gate operators, barrier gates, parking control cabinets, and access-control systems using 12 VDC, 24 VDC, or 24 VAC detector power.
- 11-pin Amphenol-style detector sockets or Reno 802-4 style harness wiring when the pinout is confirmed.
- Applications needing dual relay outputs for presence, pulse-on-entry, pulse-on-exit, or similar loop functions.
- Commonly cross-referenced with BX-4 as the later low-voltage BX Series service direction, when relay behavior and cabinet wiring are verified.
Features and Specifications
| Manufacturer | Reno A&E |
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| Product Type | Single channel dual output vehicle loop detector |
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| Part Number | B-4 / B4 |
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| Application | Low-voltage vehicle loop detection for gates, barriers, and parking controls |
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| Input Voltage | 12 VDC / 24 VDC / 24 VAC family |
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| Connector Style | 11-pin Amphenol-style rear connector |
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| Output Type | Dual relay outputs |
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| Setup | Internal DIP switches and front panel pushbutton style setup |
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| Fail Mode | Uploaded row references Fail Secure; confirm side label on the original detector |
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| Notes | Older B Series detector; BX-4 is commonly used as a later low-voltage related replacement path |
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Also Known As / Related Part Numbers
- B-4
- B4
- B-4-S
- B4S
- B-4-DP related setup variant
- Model B-4
- R-B-4
- BX-4 related low-voltage BX Series detector
- BX-LP related low-power detector family
- 802-4 11-pin harness
- LMH802-4 harness
- SKT-11 socket base
Technician Note
Do not assume every B-4 label means the same fail behavior. Reno Model B units can be configured fail-safe or fail-secure, and the side label or installation notes should be checked before ordering.
Before Ordering Checklist
- Confirm the original detector is B-4, B4, or a documented low-voltage Model B replacement.
- Verify 12 VDC, 24 VDC, or 24 VAC detector power at the socket.
- Confirm the detector uses an 11-pin Amphenol-style connector.
- Identify whether the site needs fail-safe or fail-secure relay behavior.
- Document which relay outputs are used before removing the old detector.
Important Ordering Warnings
- B-3, B-4, and B-8 look similar but are different voltage versions.
- BX-4 may be a related service replacement, but relay mode and pinout should be checked before swapping.
Professional Advisory
Vehicle loop detectors and related wiring parts should be installed with the operator power off and tested with the gate, barrier, or door system in a controlled position. Do not bypass required safety devices. If the installation involves high voltage, damaged conduit, wet junction boxes, or uncertain relay wiring, use a qualified gate or access-control technician.
Product Questions and Answers
Is the B-4 a low-voltage detector?
Yes. The Reno B-4 is the low-voltage Model B version commonly associated with 12 VDC, 24 VDC, or 24 VAC detector power.
Is B-4 the same as BX-4?
No. B-4 is an older Model B detector and BX-4 is a later BX Series low-voltage detector. BX-4 may be used in some replacement situations when voltage and relay behavior match.
What type of connector does the B-4 use?
The B-4 uses an 11-pin Amphenol-style detector connector, commonly wired with an 802-4 style harness or compatible socket.
Can this detector be used for safety loops?
It may be used for safety, exit, or presence loop functions when the operator input is wired for that function and the detector output mode is set correctly.
Why should the fail-safe or fail-secure setting be checked?
The relay behavior during power or loop failure can affect gate operation, so the replacement should match the original system design and safety requirements.
