ALARM-UNIT AL8-2 – 8‑channel alarm annunciator for reliable panel signaling

If you need a straightforward way to collect discrete fault signals and drive a common alarm or horn, the ALARM-UNIT AL8-2 typically hits the sweet spot. It consolidates up to eight digital inputs and provides two independent alarm outputs—ideal for horn/light stacks or a common alarm relay. From my experience, integrators pick it when they want a clean, DIN‑rail module that keeps alarm logic simple, serviceable, and easy to wire.

Company’s Order Placement Process and Guarantees

Key Features

• 8 digital inputs – Monitor up to eight dry contacts or transistor outputs from sensors, interlocks, or PLC points.
• 2 alarm relays – Separate outputs for horn and common alarm; handy for light stack + buzzer setups.
• Standard alarm actions – Latching/non‑latching, silence/acknowledge/reset sequences typically supported for operator workflows.
• Panel & DIN-rail friendly – Compact form factor installs cleanly in crowded cabinets.
• 24 VDC supply – Fits most control power schemes; low power draw keeps thermal load minimal.
• LED status per channel – Quick visual confirmation without opening a laptop or HMI page.
• Serviceable wiring – Pluggable terminal style (in many cases) speeds replacement and FAT/SAT work.

Technical Specifications

Application Fields

You’ll usually find the AL8-2 in OEM machines and retrofit panels where a PLC is already in place, but a dedicated alarm front end simplifies wiring and operator routines. It also fits well in:

• Water & wastewater skids – pump trip, level switch, door interlock consolidation
• HVAC/utility rooms – fan failure, thermal trips, filter differential pressure alarms
• Power distribution panels – breaker status, undervoltage/overvoltage relays
• Process equipment – E‑stop chains (status), valve limit alarms, safety gate monitoring
• Small OEM machinery – a low‑cost alternative to a full HMI alarm page

One thing I appreciate is how fast FAT testing goes—techs can jumper inputs and verify horn/light behavior without touching PLC code. A maintenance lead told us the swap time “was under 15 minutes, including labeling.”

Advantages & Value

• Procurement-friendly – Standard 24 VDC, relay outputs, and DIN rail mounting minimize surprises during integration.
• Lower commissioning risk – Fixed alarm logic means fewer PLC edits and faster SAT sign‑off.
• Serviceability – Pluggable terminal approach and LED per channel speed troubleshooting.
• Cost efficiency – In many cases, less expensive than expanding I/O and building custom alarm logic in the PLC/HMI stack.
• Compatibility – Works with dry contacts, sensors, and standard panel components like stack lights and buzzers.

Installation & Maintenance

• Cabinet & environment – Mount on 35 mm DIN rail inside a ventilated enclosure (IP54+). Keep away from high‑heat zones and VFD noise sources.
• Power & protection – Use a dedicated 24 VDC control supply with proper over‑current protection. Separate signal and power wiring to reduce EMI.
• Wiring – Land dry contacts and sensors per polarity guidance. For inductive loads on relays, add flyback diodes or RC snubbers.
• Operator controls – Provide panel pushbuttons for Silence, Acknowledge, and Reset if your procedure requires them.
• Routine checks – Quarterly test each input and both relays; verify horn/light, labeling, and any tie‑ins to PLC alarms.
• Cleaning & inspection – Dust with dry air, re‑torque terminals annually, and check for signs of condensation or vibration damage.

Quality & Certifications

This category of alarm annunciator is commonly supplied with CE and RoHS declarations. UL/CSA listing may be available depending on the build and region. If you need panel certification documentation, we can confirm the exact file set (DoC, test reports) prior to order. Typical manufacturer warranty terms in this range are one year, which aligns with our 365‑day warranty.

Suggested Supporting Components

• 24 VDC stack light (red/amber/green) with buzzer module
• 22 mm panel pushbuttons for Silence / Ack / Reset (with legend plates)
• DIN rail end clamps and ferrules for clean cable management
• RC snubbers or TVS diodes for relay contact protection