Applications Guide

CSP-4702 Static Pressure (Bypass) Control 3 Application Guide, AN0114A Rev. A
Air Pressure Connection
Connect the CSP-4702 to a dierential pressure
sensor (mounted in the supply air duct) with 1/4-
inch OD x 0.040-inch wall FR instrument and control
tubing:
1. Connect the “HI” port of the CSP-4702 to:
• Low pressure port of a pitot tube.
• Or either port of an SSS-1000 series sensor
mounted perpendicular to the air ow. (The
ow direction arrow on the sensor can point
up or down—see the diagram on page 1.)
2. The “LO” port of the CSP-4702 and the other
port of the pitot tube or SSS-100x sensor are left
unconnected and open to the air.
NOTE: To connect to 1/4-inch tubing from the CSP-
4702, an SSS-100x sensor requires a 3/8" to
1/4" barb union adapter and 1" of 3/8" OD x
0.062 “FR” tubing for connections. An SSS-
101x sensor does not require the 3/8" tubing
or adapter.
NOTE: Tubing should be free of kinks and
restrictions.
NOTE: If mounting an SSS-100x sensor
perpendicular to a relatively small diameter
round duct, be careful not break the
sensor by overtightening the screws and
overexing the plastic sensor mount.
Bypass Pressure Setpoint
To set the bypass pressure setpoint (minimum ow
limit on the CSP-4702):
1. With the conduit cover removed, connect a
voltmeter to the meter taps. The middle pin (REF)
is the common for the outer (MIN and MAX)
pins.
2. Adjust the MIN potentiometer for the desired
minimum voltage. The factory default is 0 VDC =
0" wc. Leave the MAX seing at the default 2" wc.
NOTE: 1 VDC = 1" wc. If, for example, the desired
setpoint is 0.5" wc, set the MIN voltage to
0.5 VDC.
NOTE: If a remote setpoint device is being used,
set the CSP-4702 MIN limit to 0 VDC and
MAX limit to 2 VDC (defaults).
NOTE: In bypass applications, the damper
should open (decreasing the pressure) if
the pressure input signal is higher than
the setpoint. This is opposite of VAV
applications, in which the damper closes
(decreasing the ow) if the pressure input
signal is higher than the setpoint.
To Pitot Tube (Low) OR
SSS-100x Sensor (H or L)
LIMITS
0-2 VDC / 0-2"H2O
MIN REF MAX