Technical Instructions
SW 141 Differential Static Airflow Switches
Document Number 155-052P25
June 17, 2010
Page 2
Siemens Industry, Inc.
Specifications
Operating
Measured media
Air
Switch action
Auto reset
See Table 1
Manual reset
Switch is Normally Closed (N.C.) and
only opens on increasing pressure signal.
Switch must be manually reset by operator
Ambient temperature range
−
40°F to 180°F (
−
40°C to 82°C)
Maximum overpressure
0.5 psi (3.4 kPa)
Mounting position
Diaphragm in any vertical plane
Physical
Electrical ratings
Non inductive - 15 amps @
120-277
Vac
Pilot Duty - 300 VA @ 120-277 Vac
Conduit opening
One, conduit size 1/2-inch
Sample line connectors
Two connectors, complete with nuts and
ferrules, which accept 1/4-inch OD (6.4 mm)
copper or poly tubing
Material Aluminized
steel
Agency certification
U.L.
MFHX File MH9888
CSA
1811M25
Weight
1 lb (0.45 kg)
Dimensions
See Figure 9
Accessories
High accuracy static pressure sensor
269-062
Static pressure sensing kit
189-142
Operation
The diaphragm operates a spring lever to actuate the snap switch. The manual reset
switch keeps the electrical contact open until pushed to reset. Turning the adjustment
knob clockwise increases the setpoint.
Mount the unit with the diaphragm in any vertical plane. Connect the static pressure
line(s) as shown in Figure 1.
Installation
SW0097R1
Switch
Nut & Integral
Ferrule
Tubing
Figure 1. Connecting the Static Pressure Line.
