Siemens Differential Pressure Switch for HVAC

A simple electro mechanical device that operates on the basic priciples of leevrs and opposing forces. Use to sense the difference between two points in a system - the high and low pressure.
When a change occurs in the differential pressure between the two sides of the diaphragm, the spring loaded diaphragm moves, transmitting a force to a snap switch.
** www.alienwarehaus.com**
More Tutorials :
• Video

[@LifeDL]

Very concise video, thanks,

[@hp5683]

I am going to use it in 30mbar pressure. Whenever my suction pump gets off the DPS should be able to provide a signal. Meaning from 30mbar when the pump is off the pressure will tend to increase and I want to generate a signal. How can we do with this?

[@TheMachine0021]

Be aware that this kind of DPS from siemens is for air ventilation , for liquid and gases you can use other type - check hit.sbt.siemens.com and find the sensor you need. In your case if you are going to use in 30mbar you should check the sensor pressure range. QBM81-50 pressure range is 10-50 mbar.

[@hp5683]

@@TheMachine0021 I need it for air as well. The thing is I want to give my machine a signal whenever my vacuum pump turns off. As vacuum pump turns off the pressure will try to reach to 1000mbar which is 1bar or 14.7 psi. Is this possible for this switch?

[@TheMachine0021]

Use the negative port of the sensor and connect it to the line before your vacuum - use QBM81-50 which pressure range is 10-50 mbar / 1000-5000Pa. It can give you a signal by using its contact NO or NC depends on your circuit.

[@hp5683]

@@TheMachine0021 If I set it at 50mbar set point will that mean that inside and outside pressure difference must be 50mbar? If the suction pump is doing suction at 30mbar and whenever it gets off so the pressure inside the duct will rise to 1000mbar which is the standard pressure. So, if set at 50mbar the pressure inside should rise to 950mbar to generate a signal. 1000-950=50mbar, am I right?

[@hp5683]

@@TheMachine0021 Can I get a answer for my question please?