Siemens 141-0518 Airflow Switch Differential Static Pressure,
The 141 Airflow Switch senses static differential pressure
and at setpoint open/closes a set of electrical contacts.
Applications
The 141 Airflow Switch actuates electrical circuits (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.
The manual reset switch (141-0575) should be use for
applications that require safety lock out (shut down) of the
fan. The switch can use on the fan discharge.
The auto reset switch should be used for applications that
require positive proof of airflow (or fan operation) or detect
high differential pressures associated with dirty air filters or
similar maintenance alarms that do not require safety lock
or (shut down) of the fan.

