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FEMA DPS Differential Pressure Switches for Ventilation and Air Conditioning Systems

FEMA DPS differential pressure switches are used to monitor low differential pressures in ventilation and air conditioning systems. They are particularly suitable for filter monitoring, fan monitoring and airflow control in HVAC systems. The switch detects pressure differences between two measuring points and provides an electrical switching signal when the set limit value is reached.

The DPS series is designed for air as well as non-flammable and non-aggressive gases. Typical applications include ventilation ducts, air conditioning units, air filters, fans, blowers and monitoring systems in building services engineering. This series is not suitable for fuel gases.

Depending on the version, different setting ranges are available, for example 20–200 Pa, 50–500 Pa, 200–1000 Pa or 500–2500 Pa. This allows the appropriate differential pressure switch to be selected according to the application, required switching point and expected pressure drop.

The connection is typically made via plastic connection pieces for measuring hoses. One connection is intended for the higher pressure and the other for the lower pressure. The applied differential pressure acts on a diaphragm, which actuates a switching contact. This allows the DPS to be easily integrated into control systems, alarm circuits or monitoring systems.

Typical Applications

• Filter monitoring in ventilation and air conditioning systems
• Fan and blower monitoring
• Airflow monitoring in HVAC systems
• Monitoring of pressure losses across air filters
• Differential pressure monitoring in ventilation ducts
• Monitoring of air dampers, heat exchangers or air paths
• Building services engineering, HVAC and air handling applications

Advantages of FEMA DPS Differential Pressure Switches

• For low differential pressures: suitable for typical pressure ranges in ventilation and air conditioning systems
• Ideal for filter monitoring: detects increasing pressure loss caused by clogged filters
• For air and non-flammable gases: suitable for non-aggressive gaseous media
• Various setting ranges: versions available for different pressure ranges
• Compact design: easy installation in HVAC and air handling applications
• Mechanical switching principle: no auxiliary power required for pressure detection
• Easy integration: switching signal can be used for control, alarm or system monitoring

FEMA DPS Differential Pressure Switches at ICS Schneider

ICS Schneider offers FEMA DPS differential pressure switches for monitoring air and non-flammable gases in ventilation and air conditioning systems. The devices are suitable for operators, plant builders and service companies that require a simple and reliable solution for monitoring filters, fans or airflow.

When selecting the correct DPS, the required setting range, expected differential pressure, type of application, installation situation, electrical connection, ambient conditions and medium to be monitored should be considered. For fuel gases, aggressive gases or safety-related special applications, suitable alternatives should be checked.

FAQ – Frequently Asked Questions about the FEMA DPS Differential Pressure Switch

1. What is a FEMA DPS differential pressure switch?

A FEMA DPS differential pressure switch is a mechanical switch for monitoring low pressure differences. It is mainly used in ventilation and air conditioning systems, for example for filter or fan monitoring.

2. Which media is the DPS suitable for?

The DPS is suitable for air as well as non-flammable and non-aggressive gases. This series is not intended for fuel gases or aggressive media.

3. Can the DPS be used for filter monitoring?

Yes. Filter monitoring is one of the main applications. When a filter becomes clogged, the pressure loss increases. The DPS detects this differential pressure and can trigger a maintenance or alarm signal.

4. Which setting ranges are available?

Depending on the version, different setting ranges are available, for example 20–200 Pa, 50–500 Pa, 200–1000 Pa or 500–2500 Pa. Selection depends on the expected pressure loss of the application.

5. What is the difference between DPS and DPSL?

The DPS is primarily designed for air and non-flammable, non-aggressive gases in ventilation and air conditioning systems. The DPSL, on the other hand, is designed for neutral and slightly aggressive liquids as well as non-flammable gases and can also be used as a flow switch with an orifice plate.

6. Is the DPS suitable for fuel gases?

No. The DPS series is not suitable for fuel gases. For fuel gases, appropriately approved pressure monitors or differential pressure switches must be used.

7. How does the DPS differential pressure switch work?

The switch measures the pressure difference between two connections. When the set limit value is reached, a diaphragm actuates the switching contact and provides an electrical signal.

8. Which connection is intended for the higher pressure?

Connection P1 is intended for the higher pressure, while P2 is intended for the lower pressure. This allows the differential pressure to be detected correctly.

9. Does the DPS require a supply voltage?

No supply voltage is required for pressure detection itself. An electrical connection is only required for the switching contact or switching signal.

10. Where is the DPS typically installed?

Typical installation locations include ventilation ducts, air filter units, fan sections, air conditioning units, blower systems and HVAC systems.

11. Can the DPS be used for airflow monitoring?

Yes. The DPS can be used for airflow monitoring when the airflow creates an evaluable pressure difference, for example at fans, filters or measuring points in the duct.

12. What information is important for selecting the right device?

Important information includes the required setting range, expected differential pressure, medium, mounting position, electrical connection, switching function and ambient conditions.