FOXBORO 2AX-ALM-AR

Description

Introduction to the FOXBORO 2AX-ALM-AR

Product Description

The FOXBORO 2AX-ALM-AR is a system alarm annunciator unit from Foxboro’s line of panel-mounted alarm and monitoring equipment. This device is designed to provide clear, unambiguous visual and audible indication of abnormal process conditions in industrial control systems. The FOXBORO 2AX-ALM-AR functions as a dedicated alarm display module, typically featuring two independent alarm windows (as indicated by “2AX”) that can display custom messages corresponding to specific process faults or events. It is a key component for operator awareness and is often integrated into control panels for safety-critical or high-priority alarm indication. The unit receives discrete input signals from the control system (e.g., relay contacts) and activates its associated visual display (often a backlit window with a legend card) and an optional internal audible buzzer. The design of the 2AX-ALM-AR prioritizes high visibility and reliability for immediate operator response.

Product Parameters

• Product Series: Foxboro Alarm Annunciators

• Model: 2AX-ALM-AR

• Device Type: Panel-Mounted Alarm Annunciator Module

• Number of Points: Two (2) independent alarm points.

• Display: Features two separate display windows, each with a customizable legend card (e.g., “HIGH TEMP,” “PUMP FAILURE”) and a high-intensity LED or incandescent lamp for illumination.

• Input Type: Accepts dry contact (volt-free) inputs from PLC relay outputs, DCS cards, or field switches. The “-AR” suffix may indicate a specific input logic (e.g., normally open alarm on contact closure).

• Alarm Logic: Configurable for various sequences (e.g., first-out, flashing/steady, acknowledge/reset).

• Audible Output: Typically includes an integral audible sounder (buzzer) that can be activated on alarm and silenced with an acknowledge button.

• Power Supply: Requires a low-voltage DC power supply (e.g., 24 VDC) for the logic and lamps.

• Mounting: Designed for cutout mounting in a control panel or console.

Advantages and Features

The primary advantage of the FOXBORO 2AX-ALM-AR is its dedicated, hard-wired approach to critical alarm indication, which provides a level of independence and reliability separate from the software-based alarms on a DCS or SCADA screen. Its high-visibility, dedicated display ensures that critical alarms are not missed among dozens of other indicators on a monitor. The unit offers simple, robust operation with no software configuration required beyond the initial legend card insertion and wiring. The integrated audible alert and acknowledge function provide immediate operator feedback. The rugged, industrial design ensures long-term reliability in plant environments.

Application Cases in Industry

This annunciator is used in a wide range of industries to highlight critical conditions requiring immediate operator attention. In a chemical plant, a FOXBORO 2AX-ALM-AR might be dedicated to “REACTOR HIGH PRESSURE” and “FIRE GAS DETECTED” alarms. In a power plant, it could indicate “TURBINE OVERSPEED” and “LOW LUBE OIL PRESSURE.” Within water treatment facilities, it might annunciate “HIGH TURBIDITY” and “PUMP STATION FAILURE.” It is commonly installed in local control panels for machinery, substations, and remote skids where a dedicated, unambiguous alarm is necessary for safety or equipment protection.

Comparison with Competing Products

Competing products include panel annunciators from manufacturers like Allen-Bradley (Bulletin 855), Federal Signal, and PATLITE. The FOXBORO 2AX-ALM-AR competes based on the Foxboro brand’s strong reputation in process control and the specific aesthetic and mounting compatibility with other Foxboro panel instruments. Compared to a multi-point annunciator system or a large graphic display, a simple unit like the 2AX-ALM-AR offers a cost-effective, focused solution for a small number of the most critical alarms. Its value lies in its simplicity, reliability, and independence from the primary control system’s health.

Selection Suggestions and Precautions

Selecting the FOXBORO 2AX-ALM-AR requires defining the exact alarm messages for the two points and ensuring the input logic (“-AR” for alarm on rise/closure) matches the output characteristics of the source device (PLC relay, DCS DO card). Confirm the required power supply voltage (e.g., 24 VDC) matches the available panel supply. Consider the legend card customization and ensure the display color (e.g., red, amber) meets plant standards for alarm priority.

Precautions:

• Installation should be performed by qualified panel builders or electricians.

• Ensure the dry contact inputs are truly voltage-free to prevent damage to the annunciator’s internal circuits.

• Provide a clean, stable power supply with appropriate fusing to protect the unit.

• The alarm acknowledge/test button functionality should be clearly understood by operators.

• These devices, while reliable, contain lamps/LEDs that have a finite lifespan and should be considered for periodic testing and maintenance.

• For definitive wiring diagrams, power requirements, and legend ordering information,

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