HomeMy WebLinkAboutAir Pressure Sensing Switch Cleveland Controls Model
Division of UniControl Inc.
AFS-222
AIR PRESSURE SENSING SWITCH WITH ADJUSTABLE SET POINT RANGE
APPLICATION
Model AFS-222 Air Pressure Sensing j
Switch is a general purpose proving �
switch designed for HVAC and Energy ��"__
Management applications. It may be used "�°•- -
to sense positive, negative, or differential ��j�_
air pressure.
GENERAL DESCRIPTION & �� .
OPERATION '�'` - "�� "�
��--� `..r
The plated housing contains a diaphragm,a ` ��- �"�- l� �
calibration spring and a snap-acting SPDT ` � � ,�
switch.The sample connections located on ���
each side of the diaphragm accept '/4' OD � _��
metallic tubing via the integral compression F- �.,.� ' .
ferrule and nut. 'e� +�
�`,
An enclosure cover guards against acci-
dental contact with the live switch terminal �'- "
screws and the set point adjusting screw.
The enclosure cover will accept a'/z"conduit
connection.
MOUNTING (SEE FIGURE 1) AIR SAMPLING CONNECTION
(SEE FIGURE 2)
Select a mounting location which is free from
vibration. The AFS-222 must be mounted
with the diaphragm in any vertical plane in ferrule and nut compression connections. NEGATIVE PRESSURE ONLY: Connect
orderto obtain the lowest specified operating For sample lines of up to 10 feet, '/4' OD the sample line to inlet L; inlet H remains
set point. Avoid mounting with the sample tubing is acceptable.For lines up to 20 feet, open to the atmosphere.
line connections in the"up"position.Surface use'/d'ID tubing.For lines up to 60 feet,use TWO NEGATIVE SAMPLES: Connect the
mount via the two 3/16" diameter holes in '/z' ID tubing.A'/4'OD adapter, suitable for higher negative sample to inlet L. Connect
the integral mounting bracket.The mounting slip-on flexible tubing is available:order part the lower negative sample to inlet H.
holes are 3-7/8"apart. number 18311.
TWO POSITIVE SAMPLES: Connect the
The AFS-222 is designed to accept firm-wall Locate the sampling probe a minimum of higher positive sample to inlet H. Connect
sample lines of'/4' OD tubing by means of 1.5 duct diameters downstream from the air the lower positive sample to inlet L.
(Fig. 1) source. Install the sampling probe as close
to the center of the airstream as possible. ONE POSITIVE AND ONE NEGATIVE
O Refer to Figure 2 to identify the high pres- SAMPLE: Connect the positive sample
sure inlet (H)and the low pressure inlet(L). to inlet H. Connect the negative sample
Select one of the five application options to inlet L.
listed below, and connect the sample lines
as recommended.
POSITIVE PRESSURE ONLY:Connect the
� sample line to inlet H; inlet L remains open
, to the atmosphere.
• • •
•-
� � � • -• .• • � �
i i
.. .. - . • �
. • i�
. . . .
-. ...- . . . . .
�
(Figure 2) ELECTRICAL SPECIFICATIONS
CONNECTIONS (SEE
FIGURE 3) MODEL AFS-222 AIR
High � �ow PRESSURE SENSING
Pressure Pressure Before pressure is applied to the diaphragm,
�n�et H: �n�et�: SWITCH WITH ADJUSTABLE
the switch contacts will be in the normally
Positive Only Negative Only closed (NC) position.The snap switch has SET POINT RANGE
Lower Negative� ? Higher Negative screw top terminals with cup washers.Wire
Higher Positive '— Lower Positive alarm and control applications as shown in Mounting Position:
Figure 4. Mount with the diaphragm in any verti-
(Fiqure 3) FIELD ADJUSTMENT cal plane.
Set Point Range:
N.C. N.O. The ad�ustment ran e of an AFS-222 Air +
1 g 0.05_0.02"w.c.to 12.0"w.c.
o Switch is 0.05±.02" w.c. to 12.0" w.c. To Field Adjustable"Operate Range":
� adjust the set point,t urn the adjusting screw
counterclockwise until motion has stopped. 0.07"w.c.to 12.0"w.c.
"" " Next, turn the adjusting screw 4 complete Field Adjustable"Release Range": I
turns in a clockwise direction to engage 0.04"w.c.to 11.2"w.c.
the spring. From this point, the next ten Approximate Switching Differential: �
HIGH ��W C turns will be used forthe actual calibration. Progressive, increasing from 0.02
Each full turn represents approximately ±0.01"w.c.at minimum set point to
1.2"w.c.
approximately 0.8"w.c.at maximum
Please note: To properly calibrate an air set point.
(Figure 4) switch, a digital manometer or other mea-
To prove excessive air flow or pressure: suring device should be used to confirm the Measured Media:
actual set point. Air,or combustion by-products that will
N o ALARM not degrade silicone.
� �� Maximum Pressure:
N c CONTROL 'h psi (0.03 bar).
To prove insufficient air flow or pressure: Operating Temperature Range:
N o CONTROL -40F to 180F(-40 to 82C). I
� p_ Life:
100,000 cycles minimum at 1/2 psi
N C ALARM maximum pressure each cycle and at
maximum rated electrical load.
Electrical Rating:
3.25" 3.25" 300 VA pilot duty at 115 to 277 VAC,
(82) (82) 15 amps noninductive to 277 VAC,
� 1.63." 1.38" 60Hz.
(41) 0.44" �35� Contact Arrangement: SPDT.
O O (��) Electrical Connections:
Screw-type terminals with cup
O O washers. I
2 8� Conduit Opening:
(71)
718"diameter opening accepts'/2'
O O conduit.
6.13" Sample Line Connectors:
(156) Male,externally threaded 7/16" 24
O O UNS 2A thread,complete with nuts
and self-aligning ferrules.
0.19"
�5� Sample Line Connections:
O O dia Connectors will accept'/4'OD rigid or
hole �oW semi-rigid tubing.
O O Pressure Approvals: UL, FM,CSA.
High Inlet Shipping Weight: 1.2 Ibs.
Pressure
�n�et Accessories:
1.94"(49) 0.78"
�20� • P/N 18311 Slip-on'/4'OD Tubing
3.88" 0.7�" Adapter, suitable for slipping on flex-
�gg� ��8� ible plastic tubing.
• Sample line probes.
Nominal Dimensions in Inches(Millimeters) • Orifice plugs(pulsation dampers).