Cleveland Controls AFS–442 Quick Start Manual

Cleveland Controls
Division of UniControl Inc.
Air Pressure Sensing Switch with Adjustable Set Point Range

Application

The Model AFS-442 is a general pur-
pose proving switch designed for
package burner, furnace, fuel-burning
equipment, HVAC and other Energy
Management applications. It may be
used to sense positive, negative, or
differential air pressure.
General Description &
Operation
The plated housing contains a dia-
phragm, a calibration spring and a
snap-acting SPDT switch.The sample
connections located on each side of
the diaphragm accept 1 /
8
An enclosure cover guards against ac-
cidental contact with the live switch
terminal screws and the set point ad-
justing screw. The enclosure cover will
accept a ½" conduit connection.

Mounting (see Figure 1)

Select a mounting location which is
free from vibration. The AFS-442 must
be mounted with the diaphragm in any
(Figure 1)
Bulletin AFS442.02
Dimensions in Inches
(Millimeters)
" pipe.
vertical plane in order to obtain the
lowest specified operating set point.
Avoid mounting with the sample line
connections in the "up" position. Sur-
face mount via the two
holes in the integral mounting bracket.
The mounting holes are 3-
Air Sampling Connection
(see Figure 2)
The AFS-442 is equipped with two
1
/ " – 27 NPT female connectors. For
8
sample lines of up to 10 feet,
is acceptable. For lines up to 20 feet,
use ¼" pipe. For lines up to 60 feet,
use ½" pipe. For each right angle
bend, add 4 feet to the computed
sample line length to determine correct
pipe size.For sample lines of up to 10
feet, ¼" OD tubing is acceptable. For
lines up to 20 feet, use ¼" ID tubing.
For lines up to 60 feet, use ½" ID tub-
ing. Locate the sampling probe a mini-
mum of 1-½ duct diameters down-
stream from the air source. Install the
sampling probe as close to the center
of the airstream as possible. Refer to
Figure 2 to identify the high pressure
3 / " diameter
16
inlet (H) and the low pressure inlet
(L). Select one of the five application
7 / " apart.
8
options listed below (on page 2), and
connect the sample lines as recom-
mended.
(Figure 2)
1 / " pipe
8
1
Model
AFS–442