FEMA Pressure Switches for Reliable Pressure Monitoring
FEMA pressure switches are used for the mechanical monitoring of pressure, differential pressure and vacuum in industrial systems. They switch reliably as soon as a defined limit value is reached, exceeded or undershot. This makes them suitable for applications in process engineering, mechanical engineering, heating and refrigeration systems, hydraulic systems and gas- or media-carrying installations.
Depending on the series, FEMA pressure switches are available for liquids, gases, differential pressure, vacuum and safety-related applications as pressure monitors or pressure limiters. Typical series include DCM/DNM for overpressure, DDCM for differential pressure and VCM/VNM or DNS/VNS for vacuum and low-pressure applications. Ex versions for intrinsically safe circuits are also available.
The devices operate mechanically and require no additional auxiliary power for pressure detection. The switching point is set directly on the device. When the defined pressure value is reached, the measuring element actuates a microswitch, which outputs an electrical signal or safely shuts down a process. This makes FEMA pressure switches particularly robust, durable and easy to integrate into existing systems.
Different versions are available depending on the application requirements, including fixed or adjustable switching differentials, various pressure ranges, process connections and electrical configurations. Some FEMA series can also be equipped with two microswitches, provided the selected device version supports this option.
Typical Applications of FEMA Pressure Switches
- Monitoring of minimum and maximum pressure in pipelines
- Pressure monitoring in hydraulic and pneumatic systems
- Protection of pumps, compressors, burners and pressure vessels
- Differential pressure monitoring on filters, heat exchangers or ventilation systems
- Vacuum and negative pressure monitoring in technical processes
- Safety shutdowns in case of pressure exceedance or pressure drop
- Applications with gases, liquids or non-aggressive media
Advantages of FEMA Pressure Switches
- Mechanical switching principle: reliable operation without additional supply voltage for pressure measurement
- Robust design: suitable for demanding industrial environments
- Wide product range: versions for overpressure, vacuum, differential pressure and safety applications
- Easy adjustment: switching point can be set directly on the device
- Various configurations: different pressure ranges, connections and switching functions depending on the series
- Available for Ex areas: special versions for intrinsically safe circuits are available
- Proven technology: suitable for monitoring, control and safety functions in industrial plants
FEMA Pressure Switches at ICS Schneider
ICS Schneider offers a wide selection of FEMA pressure switches for different pressure ranges and applications. The range includes mechanical pressure switches for liquids and gases, differential pressure switches, pressure monitors, pressure limiters, vacuum switches and Ex/ATEX versions. The correct device selection depends on the medium, pressure range, required switching point, maximum permissible pressure, electrical connection, switching differential and requirements regarding approvals or explosion protection.
If you are unsure which FEMA pressure switch is suitable for your application, ICS Schneider can support you with technical selection. Especially for safety-related applications, fuel gases, steam, pressure vessels or Ex areas, the design should be carefully checked based on the process data.
FAQ – Frequently Asked Questions about FEMA Pressure Switches
1. What is a FEMA pressure switch?
A FEMA pressure switch is a mechanical switching device used to monitor pressure values. As soon as a set limit value is reached, an electrical contact switches. This allows pumps, valves, controllers or safety functions to be activated.
2. Which media are FEMA pressure switches suitable for?
Depending on the version, FEMA pressure switches are suitable for liquids, gases, air, water, oil or other non-aggressive media. For special media, high temperatures or safety-related applications, the material and device selection should always be checked based on the technical data.
3. What is the difference between a pressure switch, pressure monitor and pressure limiter?
A pressure switch is generally used to monitor a pressure value. A pressure monitor is often used for monitoring and safety functions. A pressure limiter may, depending on the version, be equipped with a restart lockout, meaning that manual reset is required after shutdown.
4. What does switching differential mean?
The switching differential is the difference between the switch-on and switch-off point. It prevents the switch from constantly switching on and off due to small pressure fluctuations. Depending on the FEMA series, the switching differential is either fixed or adjustable.
5. Are FEMA pressure switches available for differential pressure?
Yes. FEMA differential pressure switches are available for applications such as monitoring filters, pumps, heat exchangers or ventilation systems. In this case, the device monitors the pressure difference between two measuring points rather than the absolute line pressure.
6. Are FEMA pressure switches available for Ex areas?
Yes. FEMA pressure switches are available in Ex versions for use in potentially explosive atmospheres or intrinsically safe circuits. These devices differ, among other things, in their electrical design and markings.
7. Does a mechanical FEMA pressure switch require a supply voltage?
No auxiliary power is required for pressure detection itself. The pressure acts on a mechanical measuring element, which actuates a microswitch. An electrical connection is only required for the switching signal.
8. How is the switching point adjusted?
The switching point is adjusted directly on the device, usually via an adjustment spindle or scale. The exact procedure depends on the respective series and should be carried out according to the operating instructions.
9. What information is needed to select the right pressure switch?
Important information includes the medium, minimum and maximum operating pressure, desired switching point, temperature, process connection, electrical connection, required protection rating, switching differential, installation situation and any required approvals such as Ex, TÜV or DVGW.
10. When should a pressure switch with lockout be used?
A lockout or restart lockout is useful when a limit value is safety-relevant and the system must not restart automatically after triggering. In such cases, the switching state must be manually reset.