Siemens Powers SW 141 Series Technical Instructions

TM
Powers
SW 141 Differential Static
Airflow Switches
Description
Application
Product Numbers
*
Setpoint accuracy tolerance and switching differential decrease proportional to setpoint decrease.
Controls
The SW 141 Airflow Switch senses static differential pressure and the diaphragm operated
snap switches actuate electrical circuits. Auto reset and manual reset models are
available.
Auto reset switches (141-0518 and 141-0574) should be used for applications requiring
positive proof of airflow (or fan operation) or to detect high differential pressures
associated with dirty air filters or similar maintenance alarms not requiring safety lock-out
(shut down) of the fan.
The manual reset switch (141-0575) should be used for applications requiring safety lock
out (shut down) of the fan. The switch can be used on the fan discharge (positive
pressure), fan inlet (negative pressure), or across the fan (differential pressure) to detect
excessively high positive pressures or low negative pressures, and turn off the fan before
damage occurs to ducts or dampers.
Product Setpoint Range
Number (Field Adjustable)
141- 1" to 12" WC
0518 (250 Pa to 3000 Pa)
141- 1" to 12" WC
0575 (250 Pa to 3000 Pa)
141- 0.05" to 1.0" WC
0574 (12.5 Pa to 250 Pa)
Technical Instructions
Document No. 155-052P25
141-0518
Table 1.
Setpoint *
Accuracy
@ 12" ± 1.5" WC
(3000 Pa ± 375 Pa)
0.6" to 1.5" WC
(150 Pa to 375 Pa)
@ 12" ± 1.5" WC
Not Applicable
(3000 Pa ± 375 Pa)
@ 1"±0.2" WC
(250 Pa ± 50 Pa)
0.06" to 0.6" WC
(15 Pa to 150 Pa)
SW 141-1
June 17, 2010
Switching * Switching
Differential Action
Approx. SPDT/
Auto Reset
SPST/
Manual
Reset
Approx. SPDT/
Auto Reset
Siemens Industry, Inc.