FCM2630/World leader in gas sensing innovation

A2L Refrigerant Gas Sensor Module
FCM2630 IEC60335-2-40 Edition 6.0 Compatible

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 TGS2630 gas sensor which has high sensitivity to various refrigerants. The TGS2630
is a semiconductor type gas sensor with an inherent resistance to mechanical shock and vibration. Its proprietary built-in filter effectively reduces the influence of alcohol and other interference gases, making it less prone to false alarms. The built-in temperature compensation circuit of the FCM2630 module reduces the influence of ambient temperature fluctuations, ensuring its reliable operation.

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.

HVAC system in the commercial sector (image)
Reference: ISO 817 Refrigerants — Designation and safety classification

FCM2630 Gas Sensor Module


TGS2630 Gas Sensor:
Highly Reliable Proven Sensor Technology

FCM2630 uses the semiconductor gas sensor TGS2630. The TGS26 series of gas sensors has a proven track record of over 20 years in the field as a sensor for use in residential gas detectors. In general, semiconductor gas sensors are resistant to mechanical shock and vibrations, and their high reliability under continuous operation for an extended period is widely recognized.

TGS2630 gas sensor has high selectivity to A2L refrigerants with small influence from interference gases such as alcohol. TGS2630 has high sensitivity to higher flammability refrigerants (A3) as well as A2L refrigerants, making it an ideal choice for the detection of future new refrigerants.

Examples of Refrigerants detectable  by TGS2630
The figure above represents typical sensitivity characteristics, all data having been gathered at standard test conditions.

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. Customized FCM2630 sensor modules calibrated for the detection of A2L or A3 refrigerants other than R-32 are also available upon request.

FCM2630-C01 Circuit Diagram

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.


Two Models of Gas Sensor Modules to Choose From


■ FCM2630-C01


■ FCM2630-E00

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-E00 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-E00
Gas sensor Semiconductor type TGS2630 Semiconductor type TGS2630
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
JRA4068:2016R - Performance class 3
IEC60335-2-40 Edition 6.0
JRA4068:2016R - Performance class 3

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, TGS2630 uses proprietary filter material in its housing 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 Enhance
Further Changeover to A2L Refrigerants
and Prevent 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 use of A2L refrigerants is increasing for new air conditioning equipment, more new HVACR systems are expected to use FCM2630 sensor modules and TGS2630 sensors.

TGS2630 has high sensitivity to a variety of A2L and A3 refrigerants and can be used for various leak detection needs, including maintenance of HVACR equipment that uses A2L or A3 refrigerants, and leak detectors for use in inspection and/or quality control processes on manufacturing lines for HVACR equipment.

For more information on A2L refrigerant gas sensors and sensor modules: