Differential Pressure Switch
The Differential Pressure Switch model AFS-22 is a general purpose proving switch designed for HVAC and energy management applications. It may be used to sense positive, negative or differential air pressure.
The plated housing on the differential pressure switch contains a diaphragm, a calibration spring and a snap acting switch. The sample connections on each side of the diaphragm accept 0.25" O.D. metallic tubing via the integral compression ferrule and nut.
An enclosure on the differential pressure switch cover guards against accidental contact with the live switch terminal screws and the set point adjusting screw. The enclosure cover will accept a 0.5" conduit connection.
APPLICATION
The model AFS-22 is a general purpose proving switch designed
for HVAC and energy management applications. It may be used
to sense positive, negative or differential air pressure.
DESCRIPTION
The plated housing contains a diaphragm, a calibration spring
and a snap acting switch. The sample connections on each
side of the diaphragm accept 0.25" O.D. metallic tubing
via the integral compression ferrule and nut. An enclosure
cover guards against accidental contact with the live switch
terminal screws and the set point adjusting screw. The enclosure
cover will accept a 0.5" conduit connection.
MOUNTING
Select a mounting location which is free from vibration.
The AFS-222 must be mounted with the diaphragm in any vertical
plane in order to obtain the lowest specified operating
set point. Avoid mounting with the sample line connections
in the UP position. Surface mount via the two 3/16"
diameter holes in the integral mounting bracket. The mounting
holes are 3-7/8" apart.
AIR CONNECTION
The AFS-222 is designed to accept firm wall sample lines
of 1/4" O.D. tubing by means of ferrule and nut compression
connections. An optional adaptor suitable for slip on flexible
tubing is available. For sample lines up to 10 feet, 1/4"
O.D. tubing is acceptable. For lines up to 20 feet use 1/4"
I.D. tubing. For lines up to 60 feet use 1/2" I.D.
tubing. Locate the sample probe a minimum of 1.5 duct diameters
downstream from the air source. Install the sampling probe
as close to the centre of the air stream as possible.
