Light grey plastic enclosure with blue front label and cable gland

Alarm signalling unit | harsh environments, PoM

(Average rating 5 of total 1 reviews)

Product description

This unit is designed to provide visual and audible alarms for HVAC systems.

It is equipped with indicators and speakers to generate both visual and audible alarms. This ensures that failures or alerts from HVAC installations in less accessible places can be easily detected and addressed promptly.

The unit is controlled using the Modbus RTU communication protocol. Modbus RTU enables communication between the signalling unit and other devices in the HVAC system, such as sensors, controllers or a building management system (BMS).

It operates on a 24 VDC power supply and provides two connection options. It can be connected via the RJ45 socket, which is commonly used for Ethernet or Modbus communication and it can also be connected via terminal blocks. It also features 3 open collector outputs.

Article code

ALR -M1

GTIN

0.540.100.300.004.5

Additional specifications and description

Purpose and connections
The ALR –M1 HVAC alarm signaling generates visual and audible alerts for failures or warnings from HVAC installations located in less accessible places. It operates using the Modbus RTU protocol for communication. The unit requires a power supply of 24 VDC and can be powered using Sentera's 24 V power supply modules.
There are two options for connecting the unit:
1. RJ45 Socket: The unit can be connected using an RJ45 socket, which is a common connector used for Ethernet connections. This allows for easy integration into an existing network infrastructure.
2. Terminal Blocks: Alternatively, the unit can be connected using terminal blocks. Terminal blocks provide a secure and reliable connection by using spring clamp terminals. The spring-loaded clamps of these terminal blocks securely grip the wires.
The unit also features three open collector outputs, which can be used to control external devices such as LED indicators or relays. By utilizing these open collector outputs, you can extend the functionality of the alarm signalling unit to activate external devices based on specific events or conditions detected by the unit.
Combining visual and audible alarms, Modbus RTU control, 24 VDC power supply, multiple connection options, and open collector outputs, this HVAC alarm signalling unit offers a comprehensive solution for monitoring and alerting HVAC system failures. It provides flexibility, ease of integration, and the ability to control external devices, enhancing the effectiveness of the alarm system and facilitating timely response and maintenance.

Pre-defined operating modes
The green, yellow and red LEDs and the piezo buzzer can be controlled via three pre-defined operating modes. These three modes can be activated via Modbus register 11. Writing '0' in Modbus register 11 will activate 'normal' mode - green LED on. Writing '1' in Modbus register 11 activates 'warning' mode: yellow LED on. Writing '2' in Modbus register 11 activates 'Alarm' mode - red LED and buzzer on. There is also the possibility to control each LED and the buzzer separately. Consult the mounting instruction for more information.

Modbus RTU communication
All settings can be adjusted via Modbus RTU. The Modbus register map provides a complete overview of all adjustable settings. Modbus HVAC alarm devices can integrate with other Modbus-enabled devices or systems, such as controllers and gateways. This integration allows for seamless communication and coordination between different components of the HVAC system, enhancing overall monitoring and control capabilities.

Installation in harsh environments
To guarantee the quality of its enclosures, Sentera produces them in its own factory. The enclosure of the ALR – M1 module is wall-mountable made of r-ABS VO (UL94) plastic. This material is heat resistant and can withstand elevated temperatures without deforming or melting. This is essential for applications where the enclosure may be exposed to heat sources. The material is also fire-retardant, it resists ignition and reduces the spread of flames. The plastic is very tough, offering excellent protection against impacts.
Besides being extremely durable, the enclosure provides an IP65 protection rating, which signifies it is well-protected against the ingress of dust and moisture. This level of protection makes it suitable even for outdoor or industrial settings where exposure to dust, moisture, or water jets may occur.