Setra 239 Operating Manual
Operating Instructions
Model 204 and 239 Pressure Transducers
Pressure Transducers (0 to 5 VDC output)
Model 204 Gauge, Absolute, and Vacuum Pressure
Model 204D Wet/Dry Differential Pressure
Model 239 Differential Pressure
General Information and Installation ..........................................................................................1
Electrical Information for Standard 24 VDC
Excitation Pressure Transducers (nominal) ..............................................................................3
Electrical Information for Optional ±15 VDC (±24 VDC)
Excitation Pressure Transducers (Option #: 621 and 622) ....................................................4
Adjustments for Pressure Transducers and Transducers
Zero and Sensitivity .......................................................................................................................5
Remote Control Instructions for Pressure Transducers ........................................................6
Installation Instructions for Multiple Hook-Up of 4-Wire
Pressure Transducers (24 VDC Excitation Units Only) ...........................................................7
Returning Products for Repair .....................................................................................................8
Calibration Services .......................................................................................................................8
EMC Certication ............................................................................................................................8
Limited Warranty ............................................................................................................................8
General Information and Installation
Your Setra transducer has been carefully calibrated before shipment to you, and it should be handled
with the same care given any precision instrument. Pressure range and dimensions are reported on
the applicable specications bulletin.
Ambient Conditions
Do not submerge in liquids, use in ambient conditions corrosive to anodized aluminum, subject to
spray or dripping, or use in a high vibration environment. The transducer is very slightly sensitive to
acceleration in the pressure tting axis (see applicable specications bulletin for acceleration response
specications). Installation is recommended in the vertical position, with the pressure port downward.
This position minimizes damage from drippage of pressure system piping.
Setra Systems, Inc.
159 Swanson Road, Boxborough, MA 01719
800.257.3872 • www.setra.com
Installation of Pressure Fittings
Your transducer is designed for most accurate operation when subjected to pressures within the
designated pressure range. Refer to the catalog bulletin specications for proof pressure limits.
Subjection to excessive pressure voids the warranty. DO NOT OVERPRESSURE.
Standard sealants such as Teflon pipe tape generally are satisfactory. For the most sensitive pressure
ranges, excessive high torquing of a metal pressure tting may cause slight zero shift which may be
trimmed out using the zero adjustment. Use of a plastic tting often shows no noticeable zero shift.
The torquing effect does not appreciably affect linearity or sensitivity. The wrench flat on the 204 and
239 series should be used when installing the positive pressure tting.
A. Positive Pressure Fitting and Media Compatibility
Model 204, 204D: 1/4”-18 NPT internal tting
For use with gases or liquids compatible with 17-4 PH stainless steel.
(316 stainless steel optional)
Model 239: 1/8”-27 NPT internal tting
For use with gases compatible with stainless steel, hard anodized
6061 aluminum, Buna N “O” ring. (stainless steel in place of aluminum
optional)
B. Reference Pressure Fitting and Media Compatibility (Differential pressure measurements only.)
Model 204D: 1/8”-27 NPT internal tting
For use with clean dry air, non- corrosive or non-conductive gases.
Maximum line pressure 1000 PSIG.
204D, 239, C239
High
Low
Model 239: 1/8”-27 NPT internal tting
For use with non-corrosive, non-condensing clean dry air or other
gases. Maximum line pressure 250 PSIG.
NOTES:
(1) Differential pressure Models can be used to measure gauge pressure by leaving the reference port
open to atmosphere.
(2) Line Pressure refers to pressure applied to both high and low sides of the sensing device
simultaneously. Refer to the product data sheet to determine maximum differential pressure and
overpressure limits.
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Electrical Information for Standard 24 VDC Excitation Pressure Transducers (nominal)
Connections (Model 204, 239; Electrical Termination Y1, Y4, Y4, Y6)
Cable Lead Function Note: Other leads in the
White Positive Excitation
Yellow Positive Output
Brown Negative Output
Black Negative Excitation
Shield Case
Connections (Model 204, 239; Electrical Termination 02, 10, 25)
Cable Lead Function
Red Positive Excitation
Black Negative Excitation
White Negative Output
Green Positive Output
Shield Case
Electrical
The electrical circuit is equivalent to a 4 terminal network, which means negative excitation lead shall
not be connected to negative signal output lead.
The pressure transducer must be operated with the case connected to earth ground to meet EMC
requirement. Best performance will be achieved by connecting the shield and negative excitation lead
if it is feasible and allowed.
cable are not used with the
standard pressure transducer
unless the transducer has
been wired for Remote
Control (see Remote Control
Instructions)
The circuit has internal protection:
• Reversed excitation voltage for at least 5 minutes.
• Short-circuit or signal output leads.
• Short duration power line transients up to 150 volts.
NOTE ON LONG CABLE USE:
In some instances, use of long cables (several hundred feet length) may introduce enough cable
capacitance into the circuit to cause output oscillations. If encountered, this oscillation may be
eliminated by connecting a 100 ohm resistor (1/8th watt or larger) in series to each of the output leads
at the end of the 2 foot transducer cable. These series resistors, of course, add to the output resistance.
Atmospheric Reference (Gauge Pressure Transducers only)
Lower range units are subject to excessive thermal zero shift unless vented to atmosphere. The electrical
cable provides this equalization vent. Do not seal the electrical cable when installing
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