A2L Refrigerant Gas Sensor Module
FCM2630 IEC60335-2-40

1. Reliable MOS type Gas Sensor inside 2.Factory Pre-calibrated to R-32 3.Temperature Compensation Circuit 4.Resistance to Shockand Vibration 5.Compact and Low Cost

FCM2630 is a factory pre-calibrated gas sensor module for the detection of the A2L refrigerant R32, using the gas sensor which has high sensitivity to various refrigerants. The A2L refrigerant gas sensor has a proprietary filter that reduces the influence of alcohol and other interference gases, resulting in lower false alarm rates. The semiconductor type sensor structure is inherently resistant to mechanical shock and vibration. The built-in temperature compensation circuit of the FCM2630 module reduces the influence of ambient temperature fluctuations, ensuring its reliable operation.

Sensor Module Lineup

Earth-friendly A2L Refrigerants
and the Requirements for Gas Sensors

The popular refrigerants currently used for air conditioning and refrigeration systems are non-flammable refrigerants (A1), which are chemically stable materials. While A1 refrigerants are safe from fire or ignition even in the event of leak from HVACR equipment, they are also greenhouse gases which cause global warming if discharged into air.

Relevant regulations are driving a transition in the HVACR industry to lower flammability refrigerants (A2L) with smaller Global Warming Potential(GWP). However, leakage of A2L refrigerants presents a risk of fire or ignition due to its flammable nature.

In order to mitigate such risk, leak detection sensors / alarms will be required in certain applications depending on amount of A2L refrigerant charge.

FCM2630 Gas Sensor Module

  1. feature 1

    Optimized Alarm Point Setting and Temperature
    Compensation for Detection of A2L Refrigerant R-32

    The FCM2630 gas sensor module is individually factory pre-calibrated to the optimal alarm set point to ensure conformity to relevant technical standards of HVACR equipment using R-32. The standard FCM2630 is pre-calibrated to R-32.

    Semiconductor gas sensors in general may show influence from ambient temperature fluctuations to a certain extent depending on the concentration of target gas. A built-in temperature compensation circuit using a temperature sensor in the FCM2630 reduces influence from ambient temperature changes on its alarm point.

    HVACR equipment manufacturers can easily add a safety function to detect A2L refrigerant leak by simply incorporating the FCM2630 sensor module into their HVACR systems without extra work for designing a temperature compensation circuit. Likewise, manufacturers do not need to adjust the alarm set point of individual gas sensors using refrigerant calibration gas.

  2. feature 2

    Two Models of Gas Sensor Modules to Choose From

    ■ FCM2630-C01
    ■ FCM2630-J0A

    FCM2630 is an embedded type gas sensor module for the detection of A2L refrigerants with two variants to choose from.

    FCM2630-C01 is a simple and cost-effective model with analog outputs that are to be connected to an external voltage comparator for generating alarm output.

    FCM2630-J0A is an advanced functionality model with monitor signal, and malfunction signal in digital output format in addition to alarm signal output.

    FCM2630 is designed to meet performance requirements for its incorporation into A2L gas detection systems that conform to the relevant standards of IEC (International Electrotechnical Commission) and the JRA (Japan Refrigeration and Air Conditioning Industry Association) when used under the conditions as shown in its specifications.

    Model FCM2630-C01 FCM2630-J0A
    Gas sensor Semiconductor type Semiconductor type
    Alarm point setting Calibrated to R-32 Calibrated to R-32
    Yes Yes
    Output signals Analog
    - Sensor output
    - Alarm threshold output
    - Monitoring / Alarm / Malfunction output
    Dimensions 25×25×16mm 25×34×16mm
    with standards
    IEC60335-2-40 Edition 6.0
    JRA4068:2021 - Performance class 3
    IEC60335-2-40 Edition 7.0
    JRA4068:2021 - Performance class 3
More details of Gas Sensor Modules

What is the Best Choice of Sensor Technology
for A2L Refrigerant Leak Detection?

Semiconductor gas sensors and NDIR gas sensors are the suitable technologies for the detection of A2L refrigerant gases available today. The advantageous features of NDIR sensors include high selectivity and accuracy, making them particularly suitable for leak detection in large scale refrigeration facilities. However, when choosing the best sensor technology for A2L detection, the drawbacks of NDIR sensors should also be taken into consideration: susceptibility to mechanical shock or vibration leading to irreversible change in output signal, reduction in sensor response when operated in a polluted/dusty environment for extended periods (due to foreign substances accumulating on the optical components), and high cost and large size.

A key advantage of semiconductor gas sensors is their high sensitivity in a low gas concentration range. Although semiconductor gas sensors may be influenced by interference gases, the sensor of the FCM2630 utilizes proprietary filter technology to eliminate the influence of interference gases such as alcohol, resulting in highly selective response to A2L refrigerant gases.

FCM2630 is a compact, cost-effective and long-life gas sensor module and the most suitable choice for A2L leak detection for use in residential air conditioning systems, packaged air conditioning systems, and VRF* systems in the commercial sector.

* VRF: Variable Refrigerant Flow

Semiconductor type
NDIR type
Sensitivity to A2L Excellent Good
Response speed Excellent Excellent
Accuracy Good Excellent
Selectivity Good Excellent
Cost Excellent Fair
Lifetime >5 years >5 years
Resistance to mechanical shock and vibration Excellent Fair
Resistance to dust Excellent Fair

Semiconductor gas sensors will contribute to
the transition towards environmentally friendly refrigerants
and the prevention of global warming.

Figaro A2L refrigerant sensor module FCM2630 has already been used commercially for packaged air conditioning systems by several major HVAC equipment manufacturers in Japan. As the shift towards eco-friendly refrigerants increases, more new HVACR systems are expected to use FCM2630 sensor modules.