Model PR-274/275
Low Pressure Transducer
Technical Information
Rev. 0
7400 Flying Cloud Drive • Minneapolis, MN 55344-3720 • USA
800-843-5116 • 952-835-1626 • Fax 952-829-5331
www.mamacsys.com
IS.PR274/275-00
For additional information, see the accompanying data sheet for this transducer.
Ordering Information
Dimensions
Figure 1.
Pressure Transducer Dimensions
Specifications
Accuracy*
:
±
1% FS
Overpressure
: 10 PSID
Supply Voltage
: 12 - 40 VDC;
12 - 35 VAC (VDC output transducers only)
Supply Current
: 10 mA maximum for VDC output
transducers; 20 mA maximum for mA output transducers
Enclosure
: 18 gage C.R. steel NEMA 4 (IP65) or panel mount
chassis
Finish
: Baked-on enamel PMS2GR88B
Compensated Temperature Range
: 25°F to 150°F (-4°C to
65°C)
T. C. Error
:
±
0.0125%/°F (.02%/°C)
Operating Temperature Range
: 0°F to 175°F (-18°C to 80°C)
Media Compatibility
: Clean dry air or any inert gas
Environmental
: 10 to 90% RH non-condensing
Termination
: Unpluggable screw terminal block
Wire Size
: 12 gage maximum
Load Impedance
: 1.6K ohms maximum at 40 VDC (mA output
transducers)
1K ohms minimum (VDC output transducers)
Weight
: Enclosure mount: 1.0 lb. (.45 kg);
Panel mount: 0.5lbs. (.25 kg)
*
Includes nonlinearity and non-repeatability.
Installation
Inspection
Inspect the transducer packaging for signs of damage. If damaged, notify the carrier
immediately.
Requirements
•
Tools (not provided):
-
Digital volt-ohm meter (DVM)
-
Appropriate screwdriver for mounting screws
-
Appropriate drill and drill bit for mounting screws
•
Appropriate accessories
•
Two #8 self-tapping mounting screws (not provided)
•
Training: Installer must be a qualified and experienced technician
W
ARNING
!
•
Disconnect the power supply before installing the transducer. Failure to do so can result in
electrical shock and equipment damage.
•
Make all connections in accordance with the job wiring diagram and national and local
electrical codes. Use only copper conductors.
•
Use electrostatic discharge precautions such as wrist straps when installing and wiring the
transducer.
•
Avoid installing the transducer in locations where severe shock, vibration, excessive
moisture, or corrosive fumes are present. NEMA 4 housings are primarily intended for
outdoor use to provide a degree of protection against windblown dust, rain, and hose-
directed water.
•
Do not exceed ratings for the transducer.
Mounting
1.
Remove the transducer cover using a Phillips screwdriver.
2.
Select the mounting location.
3.
Mount the transducer on a vertical surface with two number eight self-tapping screws (not
provided).
4.
Pull the wires through the bottom of the enclosure and make the necessary connections.
5.
Replace the cover and make the pneumatic connections.
Wiring
Use 12 AWG wire maximum for wiring terminals. Use flexible 1/4-inch outer diameter (5/32-inch
inner diameter) tubing for the high and low pressure connections. See Figures 6 to 9 for wiring
diagrams and Figures 10 and 11 for jumper designations.
Wiring for mA Output
1.
Remove the blue terminal block by carefully pulling it off the circuit board. See Figure 4.
2.
Locate the [+] and [-] terminal markings on the board.
3.
Attach the supply voltage to the [+] lead.
4.
Connect the 4 - 20 mA output ([-] terminal) to the controller’s input terminal.
5.
Ensure that the power supply common is attached to the common bus of the controller.
6.
Reinsert the terminal block to the circuit board and apply power to the transducer.
7.
Check for the appropriate output signal by using a DVM set to DC milliamps connected in
series to the [-] terminal.
Figure 4.
Pressure Transducer With mA Output
Wiring for VDC Output
The VDC output low pressure transducer is field selectable for 0 - 5 VDC or 0 - 10 VDC output
and can be powered with either 12 - 40 VDC or 12 - 35 VAC.
1.
Remove the blue terminal block by carefully pulling it off the circuit board. See Figure 5.
2.
Locate the [+], [-], and [0] terminal markings on the board.
3.
Attach the power wires to the [+] and [-] terminals. The [-] terminal is also the negative
output terminal.
4.
Connect the [0] terminal, which is the positive VDC output terminal, to the controller’s
input.
5.
Reinsert the terminal block to the circuit board and apply power to the transducer.
6.
Check the appropriate VDC output by using a DVM set to DC volts connected to the [0]
and [-] terminals.
C
AUTION
!
•
If using grounded AC, ensure that the hot wire is on the [+] terminal. In addition, if using a
controller without built-in isolation, use an isolation transformer to supply the transducer.
•
This transducer contains a half-wave rectifier power supply and must not be powered from
transformers powering other devices with non-isolated full-wave rectifier power supplies.
•
When multiple transducers are powered from the same transformer, damage will result
unless all 24-gage power leads are connected to the same power lead on all transducers.
Maintain the correct phasing when powering more than one transducer from a single
transformer.
Figure 5.
Pressure Transducer With VDC Output
PACKAGING
RANGE
OUTPUT
274
(enclosure mount)
275
(panel mount)
R1
(“ wc)
R2
(“ wc)
R3
(“ wc)
R4
(“ wc)
R5
(pa)
R6
(pa)
R7
(pa)
R8
(pa)
0 to 0.10 / -0.05 to 0.05
0 to 1.0 / 0 to 0.5 / 0 to 0.25 /
-0.5 to 0.5 / -0.25 to 0.25 /
-0.125 to 0.125
0 to 5.0 / 0 to 2.5 / 0 to 1.25 /
-2.5 to 2.5 / -1.25 to 1.25 /
-0.625 to 0.625
0 to 30 / 0 to 15 / 0 to 7.5/
-15.0 to 15.0 / -7.5 to 7.5 /
-3.75 to 3.75
0 to 25 / -12.5 to 12.5
0 to 250 / 0 to 125 / 0 to 62.5 /
-125 to 125 / -62.5 to 62.5 /
-31.25 to 31.25
0 to 1250 / 0 to 625 /
0 to 312.5 / -625 to 625 /
-312.5 to 312.5 / -156.25 to
156.25
0 to 7500 / 0 to 3750 /
0 to 1875 / -3750 to 3750 /
-1875 to 1875 / -937.5 to 937.5
mA
VDC
4 - 20 mA two-wire
0 - 5 or 0 - 10 VDC
(field selectable)
Figure 2.
Enclosure Mount
Transducer
Figure 3.
Panel Mount
Transducer
