Data Sheet for Product

Technical Instructions QBM81-… Differential Pressure Switch
Document Number CA1N1552E-P25
November 24, 2003
Specifications,
Continued
Materials
Housing Fiberglass reinforced polycarbonate
Cover Polycarbonate
Diaphragm Silicone (low-swell rubber, no ABS)
Mounting bracket Sheet-steel (galvanized)
Duct adapters ABS
Tubing PVC, soft
Connections Electrical connection 3 screw terminals
Cable entry PG11 cable gland
Pressure connections Male, ø 0.24-inch
Weight and Dimensions Weight (including packaging) 0.42 lb. with mounting bracket
Dimensions See Figures 5 and 6
General Ambient
Conditions
Ambient temperature
Operation –4°F to 185°F (–20°C to 85°C)
Storage –40°F to 185°F (–40°C to 85°C)
Ambient humidity <90% rh (non-condensing)
Mounting Orientation Any. See Commissioning Notes.
Agency Approvals Protection class Class 2
Protection standard IP54 to IEC529
Combustion class to UL94
Pressure casing and housing V-0
Cover HB
Plastic tubing V-2
Duct adapters HB
Conforms to CE requirements
* The switching differential is factory-set to a fixed value (See Figure 2), and the
adjustment screw is sealed with paint (approximately one turn counterclockwise from
the end-stop).
Wiring Terminals
SMIS0079R1
1
2
3
Ph
SWITCH CONNECTS 1-2 ON PRESSURE FALL
SWITCH CONNECTS 1-3 ON PRESSURE RISE
p
Figure 3. Wiring Terminals.
Application
Examples
p
+
p
+
SMIS0080R1
+ Pressure upstream of filter + Pressure downstream of filter
Pressure downstream of filter Pressure upstream of fan on inlet
side or open to atmospheric
pressure. With radial fans, locate
at inlet center
Figure 4. Application Diagram.
Page 4 Siemens Building Technologies, Inc.