Siemens QBM81-10 Differential Pressure Switch For Air And Nonaggressive Gases

Differential Pressure Switch QBM81-…

for air and nonaggressive gases

For ventilation and air conditioning plants

To monitor air filters, air flow, fan belts

To monitor pressure in clean rooms, kitchens etc.

Easy to mount

>1 mio switching cycles

Highly precise setting

Long-term stability

Use

In ventilation and air conditioning plants to:

Monitor differential pressure, underpressure and overpressure

Monitor air filters and air flows

Recognize torn fan belts

Differential pressure switches can be used in clean rooms, kitchens, etc.

Type summary

Siemens Differential pressure switch QBM81-… CA1N1552E

Building Technologies 2014-07-30

Ordering

When ordering, please indicate quantity, name and product number. Example:

1 differential pressure switch QBM81-5

The accessory duct probe FK-PZ3 are included in the delivery. Additional accessories must be ordered separately.

Mechanical design

The differential pressure switch QBM81-... consists of:

Housing and cover

Diaphragm

1 sheet-steel mounting bracket

Accessory duct probe connection kit (FK-PZ3):

2 duct adaptors

4 fixing screws

2 m tubing, 5/8 mm dia.

Accessories

For precise measurements, two additional duct probe sets must be delivered; see also data sheet CA1N1589E:

FK-PZ1 Set containing two stainless steel duct adaptors with rubber grommet

FK-PZ2 Set containing two duct adaptors with aluminum fixing rosettes,

4 screws

Technical design

The differential pressure between the two pressure connections deflects a springloaded diaphragm. This special diaphragm ensures the long-term stability of switching points.

Each type is engraved with individual scales for very precise adjustment. The adjustment options are illustrated in the 5 diagrams in Section "Functions" below.