Cleveland Controls AFS–460–136 Data Sheet

Model

AFS–460–136

Manual Reset DPDT Air Pressure Sensing Switch for 120 VAC Applications

Application

The Model AFS-460–136 is a general
purpose airflow proving switch designed
for 120 VAC HVAC and Energy Man­agement applications where a manual
reset switch with DPDT contacts is de­sirable. It may be used to sense posi­tive, negative, or differential air pres­sure.

General Description &
Operation

The plated housing contains a dia­phragm, a calibration spring, a snap-act­ing switch with manual reset button, and
a dpdt relay.

The sample connections located on each
side of the diaphragm accept .25" OD
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. The manual
reset button is located on the top sur­face of the enclosure cover.

(Figure 1)

Mounting (see Figure 1)

Select a mounting location which is free
from vibration. The AFS-460–136 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 Sampling Connection
(see Figure 2)

The AFS-460–136 is designed to accept
firm-wall sample lines of ¼" OD tubing
by means of ferrule and nut compres­sion connections. An optional ¼"
adapter, suitable for slip-on flexible tub­ing is available. 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
tubing. Locate the sampling probe a
minimum of 1.5 duct diameters down­stream 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
inlet (H), and the low pressure inlet (L).
Select one of the five application op­tions listed below, and connect the
sample lines as recommended.

(Figure 2)

Bulletin AFS 460136.03

Cleveland Controls

Division of UniControl Inc.

LOW
PRESS

MANUAL

NC

RESET

HIGH
PRESS

C

CONVERTER

K1

NO 1

H

TB2 #1
120 V AC

Shown in "o n shelf " condit ion:
no power and no differential
pressure appli ed.

POSITIVE PRESSURE ONLY: Con­nect the sample line to inlet H; inlet L
remains open to the atmosphere.

NEGATIVE PRESSURE ONLY: Con­nect the sample line to inlet L; inlet H
remains open to the atmosphere.

TWO NEGATIVE SAMPLES: Con-

C 1

C 2

Note that wh en power is applied across
H and N :

1) Relay K1 is energized

2) Contacts change state (i. e., NO contact
closes and NC contact opens)

3) LED is illuminated when differential
pressure exceeds set point.

field adjustable set point, the snap
switch opens, de-energizing the coil on
the slave relay, which activates the
DPDT contacts. An LED indicates that
the snap switch exceeds differential set
point. It remains lit until the manual re­set push button is depressed.

nect the higher negative sample to inlet
L. Connect the lower negative sample

Field Adjustment

to inlet H.

TWO POSITIVE SAMPLES: Con­nect the higher positive sample to inlet
H. Connect the lower positive sample
to inlet L.

ONE POSITIVE AND ONE NEGA­TIVE SAMPLE: Connect the positive

sample to inlet H. Connect the negative
sample to inlet L.

The AFS-460–136 Manual Reset Air
Switch has an adjustment range of 0.40
to 12.0" w.c., ±.06" w.c. To adjust the
set point:

Turn the adjusting screw counterclock­wise until motion has stopped. Next,
turn the adjusting screw 4 complete
turns in a clockwise direction to engage
the spring. From this point, the next ten

Electrical Connections
(see Figure 3)

turns will be used for the actual cali­bration. Each full turn represents ap-

proximately 1.16" w.c.

Before pressure is applied to the dia­phragm, the snap switch contacts will be
in the normally closed (NC) position.
As differential pressure rises above the

Please note: To properly calibrate an
Air Switch, a digital manometer or
other measuring device should be used
to confirm the actual set point.

Bulletin AFS 460136.03 2

Specifications

Model AFS–460–136 Air

Pressure Sensing Switch with

manual reset feature, DPDT

contact arrangement, for 120

VAC applications.

Sample Media: Air or

combustion by-products that will
not degrade silicone.
Mounting Position (in order to
meet lowest operating
specifications): Diaphragm in any
vertical plane.

Field Adjustable Range:

0.40 ± .06"w.c. to 12.0"w.c.
Switch Differential: Progressive,

NC1

TB2 #2

NC 2 NO 2

increasing from approximately
.06± .01"w.c. at minimum set
point, to approximately .8"w.c. at
maximum set point.

Maximum Pressure:

0.5 psi (0.03 bar)

Operating Temperature Range:

-40 to 180F (-40 to 82C)

Electrical Rating:

4.5 VA @ 120 V AC, 50/60 Hz.

Contacts:

DPDT, 2 form-C
rated 8 amp @ 250 V AC.

Electrical Connections:

Screw terminals.

Sample Line Connections:

Ferrule and nut compression type
connectors will accept .25" OD
rigid tubing.

Shipping Weight: 1.2 lbs.
Agency Approvals: pending

Pressure Conversion Table

1" H2O = .0361 lbs./sq. in. or .0735 in. mercury
1" Hg. = .491 lbs./sq. in. or 13.6 in. water
1 psi = 27.7 in. water or 2.036 in. mercury

Accessories

• P/N 18311 Slip-on ¼" OD Tubing Adapter,
suitable for slipping on flexible plastic
tubing. • Sample line probes. • Orifice

plugs (pulsation dampers).