Add wired smoke detector
This page covers the device-specific wiring for a System Sensor 2012J or 4WTAR-B wired smoke detector. For general device setup and settings, see Add a device.
The wired smoke detector triggers a BRNKL alert when smoke is detected, even when no one is aboard. Useful for early fire detection in the engine room, salon, or any enclosed space.
Uses a digital input slot (4–7) on the BRNKL connector.
For BRNKL Blue wiring, see BBLU Add wired smoke detector. Wiring differs between the two systems — the relay common connects to ground on the BRNKL 5G, not to +DC as on BRNKL Blue.
Prerequisites
System Sensor 2012J or 4WTAR-B smoke detector
12–24 V DC unswitched power supply (fused)
Marine-grade wiring if extending the supplied leads
An available BRNKL digital input (slot 4, 5, 6, or 7)
Disconnect shore power and turn off the main DC breaker before working on the BRNKL connector.
Wiring
Both detectors use a relay output that closes when smoke is detected. The relay common (C) connects to ground — when smoke is detected, the relay closes and pulls the BRNKL input to ground, triggering an alert.
System Sensor 4WTAR-B
Terminal | Function | Connects to |
|---|---|---|
(1) + IN | DC power | +12/24 V DC (fused) |
(3) − IN/OUT | Ground | Common ground |
(7) C | Relay common | Common ground |
(8) NO | Relay normally open | BRNKL connector — slot 4, 5, 6, or 7 |
System Sensor 2012J
Terminal | Function | Connects to |
|---|---|---|
+ (Power) | DC power | +12/24 V DC (fused) |
− (Power) | Ground | Common ground |
C (Relay) | Relay common | Common ground |
NO (Relay) | Relay normally open | BRNKL connector — slot 4, 5, 6, or 7 |
Note which slot you use — you will need it when configuring.
Install the detector
Mount on the ceiling or high on a wall in an enclosed space where smoke accumulates quickly.
Follow the manufacturer's placement guidelines for the specific model.
Use a fused DC power supply sharing the same ground reference as the BRNKL 5G.
Configure
In the BRNKL app, go to Settings > Devices and select the input matching your slot:
Slot | App setting |
|---|---|
4 | Digital 1 |
5 | Digital 2 |
6 | Digital 3 |
7 | Digital 4 |
This is a Digital input. Recommended settings:
Monitor — on
Alert — on
Name — e.g., Smoke detector
High Name — Alarm
Low Name — Clear
Alert On — High (alerts when smoke is detected)
Consider enabling alerts so notifications are sent even when BRNKL is disarmed — a smoke alarm is always worth knowing about immediately.
Tap Save.
Test
Wait 15 minutes for settings to sync.
Confirm the dashboard shows Clear with no smoke present.
Use a smoke detector test spray (or briefly hold a smouldering match nearby) to trigger the alarm. The dashboard should switch to Alarm and send an alert.
Ventilate the area and confirm the detector resets to Clear.
Test the detector regularly to verify proper operation. The 4WTAR-B supports interconnect wiring for up to 12 smoke alarms — when one triggers, all connected alarms sound. See the System Sensor installation manual for details.
Troubleshooting
Dashboard shows Alarm with no smoke present — check for steam, dust, or exhaust near the detector. Relocate if the installation environment causes false triggers.
Detector doesn't trigger dashboard — verify relay common (C) is wired to ground (not +DC), the NO terminal goes to the correct BRNKL slot, and the correct Digital input is enabled in the app.