Reno A&E BX-4 Low Voltage BX Series Single Channel Loop Detector
The Reno A&E BX-4 is the low-voltage model in the BX Series single-channel loop detector family. It is used when a vehicle loop is connected to a gate operator, barrier arm, parking controller, or access-control panel and the detector socket is supplied with low-voltage power rather than 120 VAC or 240 VAC. The BX-4 is one of the most common Reno detector service options because it covers many 12 VDC, 24 VDC, and 24 VAC style control cabinet applications. It provides one loop input and dual relay outputs, making it useful for safety, exit, presence, hold-open, and pulse style loop functions when configured correctly. The BX-4 is also commonly tied to older BX-LP or Model B low-voltage replacements, but it should be ordered by actual site voltage and wiring, not just by cabinet brand or a similar-looking detector body.
Compatible With
- Select gate operators, barrier gates, parking control cabinets, and access-control panels using low-voltage detector power.
- BX Series applications calling for BX-4, BX4, or the low-voltage BX detector.
- Commonly associated with replacement of older low-voltage Reno detector families such as BX-LP, AX-4, and B-4 when voltage, pinout, and relay behavior are confirmed.
- 11-pin detector installations using Reno 802-4 style harnesses, LMH802-4 style harnesses, or SKT-11 style socket bases when wiring matches.
- Vehicle loop applications including exit loops, safety loops, reversing loops, presence loops, and hold-open loops.
Features and Specifications
| Manufacturer | Reno A&E |
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| Product Type | BX Series single channel vehicle loop detector |
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| Part Number | BX-4 / BX4 |
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| Application | Low-voltage vehicle detection for gates, barriers, parking, and access control |
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| Input Voltage | 12 VDC / 24 VDC / 24 VAC family, often described as 10 to 35 VAC or VDC |
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| Output Type | Dual relay outputs |
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| Connector Style | 11-pin Amphenol-style detector connection |
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| Setup | Eight external DIP switches and eight-position rotary sensitivity switch |
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| Related Models | BX-3 120 VAC and BX-8 240 VAC are related voltage models, not automatic substitutes |
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| Notes | Frequently used as a current replacement direction for some older low-voltage Reno detectors |
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Also Known As / Related Part Numbers
Technician Note
A BX-4 is commonly used in low-voltage detector cabinets, but the voltage should still be measured at the socket. Some older cabinets mix low-voltage accessory circuits with line-voltage terminals in the same enclosure.
Before Ordering Checklist
- Confirm the detector power source is low voltage, not 120 VAC or 240 VAC.
- Match the original detector label or replacement instructions to BX-4.
- Record DIP switch, sensitivity, and relay output settings from the old detector.
- Inspect loop and lead-in wire condition before replacing the detector.
- Confirm whether the controller needs fail-safe, fail-secure, conventional, or reversed output behavior.
Important Ordering Warnings
- Do not install BX-4 in a 120 VAC BX-3 socket or 240 VAC BX-8 socket.
- BX-LP, AX-4, B-4, and BX-4 are related low-voltage detector references, but final fitment depends on the cabinet wiring and relay needs.
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
What voltage range is the BX-4 used for?
BX-4 is the low-voltage BX Series detector and is commonly associated with 12 VDC, 24 VDC, and 24 VAC detector power applications.
Does BX-4 replace the discontinued BX-LP?
BX-4 is commonly listed as a replacement direction for BX-LP, but the site voltage, pinout, and output configuration should be confirmed.
Can BX-4 be used for both exit and safety loops?
Yes, it may be used for either function when wired to the correct controller input and configured for the needed relay behavior.
Is BX-4 the same as BX-3?
No. BX-4 is low-voltage, while BX-3 is 120 VAC. They are related BX Series models but not voltage-interchangeable.
What accessories are commonly used with BX-4?
A Reno 802-4 style 11-pin harness or SKT-11 style socket base may be used when the control cabinet is wired for an 11-pin detector.
