Setra 276 Operating Manual

Operating Instructions

Model 276 Barometric Pressure Sensor

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. Accuracy and dimensions are reported on the specifica­tions bulletin for the transducer.

The label on the unit specifies the calibrated output voltages at the low end and the high end of its pres­sure ranges.

Ambient Conditions

Do not use in ambient conditions corrosive to the stainless steel housing or PVC jacketed cable, sub­merge in liquids, or subject to spray or vibration environment.

Electrical Connections:

“Belden” Cable Lead
Function (#8723 Grey Cable)
positive excitation Red
positive output Green
negative output White
negative excitation Black
case Shield

Electrical

The electrical circuit is a 3-terminal circuit. Separate leads for negative output and negative excitation are
provided for convenience in wiring but are internally commoned. Use of these leads also avoids errors in
voltage readings caused by ground loops which can occur on 3 wire devices.

The pressure transducer should be operated with the shield connected either to the negative excitation
wire or to the negative output wire. Failure to do this may result in unsatisfactory operation of the unit.

NOTE: The circuit is not protected against mis-wiring. Use extreme care in wiring the positive
excitation voltage only to the red wire, and to ensure all four leads are correctly connected before
applying power. REVERSED OR MIS-WIRED EXCITATION MAY CAUSE PERMANENT DAMAGE TO
THE TRANSDUCER.

In some instances, use of long cables (several hundred feet long) may introduce enough cable capaci­tance into the output circuit to cause output oscillation. If encountered, this oscillation may be eliminated
by connecting a 100 ohm resistor (1/8 watt or larger) in series to each of the output leads at the end of the
2 foot transducer cable. These series resistors add to the output resistance

Calibration

This unit has been precision calibrated at the factory. It has been designed to be inherently stable;
recalibration adjustments are not normally field accessible. If you do wish to perform a recalibration, and
have access to a high accuracy primary pressure standard, call the factory for instructions on field access
to the calibration adjustments.

RETURNING PRODUCTS FOR REPAIR

Please contact Setra (1-800-257-3872, 978-263-1400) before returning unit for repair to review informa­tion relative to your application. When returning a product to Setra, the material should be carefully
packaged and shipped prepaid to:

Setra Systems, Inc.
159 Swanson Road
Boxborough, MA 01719
Attn: Repair Department

To assure prompt handling, please supply the following information and include it inside the package of
returned material:

1. Name and phone number of person to contact.

2. Shipping and billing instructions.

3. Full description of the malfunction.

4. Identify any hazardous material used with product.

Notes: Please remove any pressure fittings and plumbing that you have installed and enclose any
required mating electrical connectors and wiring diagrams.

Allow approximately 3 weeks after receipt at Setra for the repair and return of the unit.

Non-warranty repairs will not be made without customer approval and a purchase order to cover repair
charges.

LIMITED WARRANTY AND LIMITATION OF LIABILITY

SETRA warrants its products to be free from defects in materials and workmanship, subject to the following terms and
conditions:
Without charge, SETRA will repair or replace products found to be defective in materials or workmanship within the
warranty period; provided that:

a) the product has not been subjected to abuse, neglect, accident, incorrect wiring not our own, improper

installation or servicing, or use in violation of instructions furnished by SETRA;
b) the product has not been repaired or altered by anyone except SETRA for its authorized service agencies;
c) the serial number or date code has not been removed, defaced, or otherwise changed; and
d) examination discloses, in the judgment of SETRA, the defect in materials or workmanship developed under

normal installation, use and service;
e) SETRA is notified in advance of and the product is returned to SETRA transportation prepaid.

Unless otherwise specified in a manual or warranty card, or agreed to in a writing signed by a SETRA officer, SETRA
pressure and acceleration products shall be warranted for one year from date of sale.

The foregoing warranty is in lieu of all warranties, express, implied or statutory, including but not limited to, any
implied warranty of merchantability for a particular purpose.

SETRA’s liability for breach of warranty is limited to repair or replacement, or if the goods cannot be repaired or
replaced, to a refund of the purchase price. SETRA’s liability for all other breaches is limited to a refund of the
purchase price. In no instance shall SETRA be liable for incidental or consequential damages arising from a breach
of warranty, or from the use or installation of its products.

No representative or person is authorized to give any warranty other than as set out above or to assume
any other liability in connection with the sale of its products.

for SETRA

159 Swanson Road, Boxborough, MA 01719-1304; 800-257-3872;
[phone]; Fax. [phone]; WEB; www.setra.com;
E-mail: [e-mail]