Setra Systems 280G Operating Instructions

Model 280G Pressure Transducer and Pressure Transmitter
Three-Wire, Voltage Output—Two Wire, Current Output

General Information

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 ranges and dimensions are reported on
the specification bulletin for the transducer.

Installation

Do not use in ambient conditions corrosive to stainless steel, submerge in liquids, subject to spray
or drip, or in a high vibration environment. The 280G Series is slightly sensitive to acceleration in
the pressure fitting axis, less than 0.05 psi/g typical. Factory calibrated in the vertical position, with
pressure port downward, this position often minimizes potential damage from dripping of pressure
system piping.
Installation of pressure fitting:
For very high pressure we suggest using a sealant such as Loctite hydraulic sealant. For other pressure
ranges, standard sealants such as Teflon pipe tape generally are satisfactory. For the most sensitive
pressure ranges, excessive torquing of a metal pressure fitting may cause slight zero shift which may
be trimmed out using zero adjustment. Use of plastic fittings often shows no noticeable zero shift.
The torquing effect does not appreciably affect linearity or sensitivity. Use the wrench flats on the
280G when attaching to fittings.
Atmospheric Reference (Gauge pressure units only)
Lower range units are subject to excessive thermal zero shift unless vented to atmosphere. The 280G
Series gauge pressure transducers and transmitters are vented to atmosphere at the terminal strip.

Electrical Connections

280G (.08 - 5.08 VDC output)
For 24 VDC Excitation (Nominal)
+ IN
+ OUT
COM.
Care must be taken when installing this transducer that the excitation voltage is not applied to the
output lead by mistake. Excitation power, or voltage in excess of 30 VDC, inadvertently applied to
the output lead may damage the electrical circuit. Shielding or other precautions should also be
provided to assure that transient voltages in excess of 30 VDC are not applied to the output lead.

Wiring

Current Output (4-20 mA)
The circuit is designed to operate as a true two-wire 4 to 20 milliampere pressure transmitter
and will deliver rated current into any external load between zero and 800 ohms.
Operating Instructions
Connect to 12-30 VDC Power Supply.
Connect to Control of Pressure Monitor.
Connect as Common Return Lead for + IN
and + OUT.
CAUTION: