Installation Guide ✓ ISO 9001: 2000 Certified 1-800-257-3872 Toll Free 1-978-264-0292 Fax www.setra.
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Table of Contents 1.0 GENERAL INFORMATION ............................................................................................... 4 2.0 MECHANICAL INSTALLATION ...................................................................................... 4 2.1 Media Compatibility .......................................................................................... 4 2.2 Environment ......................................................................................................... 4 2.
Setra Model 256 Pressure Transducer 1.0 GENERAL INFORMATION Every Model 256 has been tested and calibrated before shipment. Specific performance specifications are listed on Page 7 of this Guide. Setra Systems 256 pressure transducers sense gage pressure and convert this pressure to a proportional high level analog output. Two output versions are offered: A voltage output of .1 to 5.1 VDC, and a current output of 4 to 20 mA. 2.0 MECHANICAL INSTALLATION 2.
2.6 Mounting Accessories The Model 256 is provided with a bracket and two hex bolts for mounting and a 1/2” NPT plug for the unused conduit opening. The bracket is suitable for mounting with a Ubolt or a band clamp. There are 1/4-20 UNC threaded holes on the back of the 256 transducer for direct mounting and/or grounding. 3.0 ELECTRICAL INSTALLATION Wiring is through a 1/2” conduit opening. Remove the screw cover to access the removable wiring terminal block connector.
3.2 Current Output Units The 4-20 mA current output units are designed to have current flow in one direction only - PLEASE OBSERVE POLARITY. We suggest that the electrical conduit shield be connected to the system’s loop circuit ground to improve electrical noise rejection. The Model 256 is a two-wire loop-powered 4 to 20mA current output unit and delivers rated current into any external load of 0-800 ohms. (See Diagram 2 for location of +EXC and -EXC current output screw terminals.
4.3 Current Output Zero Adjustment While monitoring the current output, and with the pressure port open to atmosphere or with zero pressure applied, the zero may be adjusted by turning the zero potentiometer screw. The factory setting is 4mA (±.08mA). 4.4 Current Output Span Adjustment Span or full scale output adjustments should only be performed by using an accurate pressure standard (electronic manometer, digital pressure gage, etc.) with at least comparable accuracy to the 256 transducer.
6.0 RETURNING PRODUCTS FOR REPAIR Please contact a Setra Systems application engineer (1-800-257-3872, 1-978-263-1400) before returning unit for repair to review information relative to your application. Many times only minor field adjustments may be necessary. When returning a product to Setra Systems, the material should be carefully packaged and shipped prepaid to: Setra Systems, Inc.
