Cleaveland Controls RFS-4150 User manual

·Cleveland Controls
Di-".ision~of UniControl Inc.
Model·
RFS-4150
/
AIR PRESSURE SENSING SWITCH WITH ADJUSTABLESET POINT
APPLICATION
•'
Model RFS-4150 is a general purpose prov-
ing switch designed for HVAC and Energy
Management-applicatipns. This switch can
be used to sense positive, negative,
or dif-
ferential air pressure.
GENERAL DESCRIPTION &
OPERATION
The plated hotJsiog_contains_a__dlapbLagm~<L~ __ -------,
calibration spring, and a snap-acting switch.
The sample line connections located on
each side
of the diaphragm accept o/is", W',
and 7'\s" flexible tubing. Various electrical
connections are available.
MOUNTING {FIG. 1)
Select a mounting location which is free
from vibration. The Model RFS-4150 must
be mounted with the diaphragm
in any verti-
cal plane
in order to maintain the specified
operating set point. Avoid mounting with the
sample line connections
in the "up" position.
The standard model
is surface~mounted via
th~ two round holes (0.14" dia.) ortwo of the
fourslots
(o/is" wide) on the zinc-plated strap
bracket.The mounting holes and slots are
3-Va" apart. Custom mounting configurations
are available.
Figure 1: Mount with the diaphragm in
any vertical plane.
- -~,-~
·~ \1)
AIR SAMPLING CONNECTION
{FIG. 2)
Tri-barbed sample line connectors suitable to
accept flexible tubing are situated on either
side
of the diaphragm as shown in Figure
2. The tri-barbed connectors accept ·o/is",
Y..", and o/;s" ID flexible tubing. For sample
lines up to 10 feet
in length, 11s" ID tubing
is acceptable. For lines up to 20 feet, use
Y.." ID tubing.
Locate the sampling probe a minimum
of
Figure 2
INLET
Positive Only
LowerNegative
HigherPositive
NLETL
Negative Only
HigherNegative
LowerPositive
-- -1;5-ductl:liameters-downstreamiromth.::.-.:H.·--+t=lctu.r:e ~--- --- ------+
source. Install the sampling probe as close
to the center of the airstream as possible.
Refer to Figure 2 to identify the high pres-
sure inlet (H)
and the low pressure inlet
(L). Selectone ofthe five application options
listed below, and connect the sample lines
as recommended.
HIGH
PRESSURE
LOW
PRESSURE
0
N.C. N.O.

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; inlefH remains open
to the atmosphere. · ·
Two Negative Samples: Connectthe higher
negative sample
to inletL. Connectthe lower
negative sample to inlet'
H. \
Two Positive Samples: Connectthe higher
' positive sampleto inlet
~ Connectthe lower
positive sample to inlet
L.
\
One·Positive and One Negative Sample:
Connectthe positive sampleto inlet H. Con-
nect,the negative sample to inlet
L,.
Figure 4
To prove excessive air flow or pressure:
...,.NO ALARM
c e-_____-
~--------~~N~~c+-C-0-N-TROL
To prove insufficient air flow or pressure:
JlO CONTROL
c 0--___:__""
....... Q--1----
~--------~N~C ALARM
4.098(104)
ELECTRICAL CONNECTIONS
(FIGURES 3 &
4}
Beforepressure is applied to the diaphragm,
the switch contacts will be in the normally
closed (NC) position. Wire control and alarm
functions
as shown in Figure 4.
FIELD ADJUSTMENT
The adjustment range of an RFS-4150 Air-
Switch is 0.15±0.02" we to 5.0"wc.
To adjust the set point, t~rn the adjusting
screw counterclockwise .until motion has
stopped. Next, turn the adjusting screw 5
complete turns clockwis'll·to
engage the
spring.
;•
From this p~t, the nexteight turns will be
used fortheiactual calibratibn. Each full turn
represents
a~proximate'iy 0.61" we.
Please note: To properly calibrate an air
switch, a digital manometer
or other mea-
suring device should be used to confirm the
actual set point. ' ·
1----- .3.066(78)----1
Reference Dimensions in Inches (Millimeters)