Omega Products PX274 Installation Manual
Low Pressure Transducer
PX274, PX275, PX277, and PX278
M2759-0305
SPECIFICATIONS
Accur acy*:± 1%
FS
Overpressure: 10
PSID
Supply Voltage: 12 - 40
VDC
; 12 - 35
VAC (VDC
output
transducers only)
Supply Current:10
M
A
maximum for VDC outp ut
transducers; 20
M
A
maximum for
M
A
output transducers
Enclosure: 18 Ga. C.R. steel NEMA-4 (IP-65) or panel mount
cha ssis
Finish: Baked on enamel PMS2GR88B
Compensated Temperature Range: 25°
F
to 150°F (-4°C to
65°
C
)
T. C . E rr o r:
±
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-condens ing
Te rm in a ti o n: Unpluggable screw terminal block
Wire Size: 12 Ga. maximum
Load Impedance: 1.6K ohms max. at 40
VDC
(
M
A
output
transducers); 1K ohms min. (
VDC
output tr ansducers)
Weight: Enclosure moun t: 1.0 lb. (.45 kg); Panel mo unt: 0.5
lbs. (.25 kg)
*
Includes nonlinearity, hysteresis, and non-repeatability.
INSTALLATION PRECAUTIONS
Do not use on oxygen service, in an explosive or hazardous
environment, or with flammable or combustible material.
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 electrostatic discharge precautions such as wrist straps
when installing and wiring the transducer.
Do not exceed ratings for the transducer.
If using grounded AC, ensure that the hot wire is on the [+]
terminal. Also, 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 tr ansformers p owering 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.
WIRING
Use 12
AWG
wire maximum for wiring terminals. Use flexible
¼-inch O.D. (5/32-inch I.D.) tubing for high and low pressure
connections.
The
M
A
output transducer must be powered with a 12 - 40
VDC
power supply. The
VDC
output 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
.
Wiring the PX-274 and PX-275:
1. Remove the blue terminal block by carefully pulling it
off the circuit b oard.
2. Note the block’s terminal markings on the circuit board.
3. If using an external power supply, connect the supply
voltage wire to the [+] terminal. Connect the power
supply common to the common bus of the controller/
meter. Connect th e input sign al of the cont roller/meter
to the [-] term inal.
4. If using a controller/meter with an internal
power supply, connect the controller/
meter input signal to the [+] terminal.
Connect the cont roller/meter common to the [-]
terminal.
5. Reinsert the terminal block onto the circuit board and
apply power to the transducer.
6. Check for the appropriate output signal using a digital
voltmeter set to DC milliamps connected in series to
the [-] term inal.
Wiring the PX-277 and PX-278:
1. Remove the blue terminal block by carefully pulling it
off the circuit board.
2. Note the block’s terminal markings on the circuit board.
3. Connect the power supply voltage wire to the [+]
terminal and the power supply common to the [-]
terminal.
4. Connect the controller/meter input wire to the [0]
terminal and the controller/meter common wire to the
[-] terminal.
5. Reinsert the terminal block onto the circuit board and
apply power to the transducer.
6. Check the appropriate VDC outpu t using a digital
voltmeter set to DC volts connected to the [0] and [-]
terminals.
PRESSURE RANGES AND JUMPER
CONFIGURATIONS
Jumper Configurations
Jumper Configurations for mA Output Transducers
Jumper Configurations for VDC Output Transducers
CALIBRATION
All transducers are factory calibrated to meet or exceed
published specifications. If field adjustment is necessary,
follow these instructions:
1. Connect a 12 - 40
VDC
or 12 - 35
VAC
power source to the
[+] and [-] terminals.
2. If calibrating an
M
A
output transducer, connect a digital
voltmeter in series to the [-] terminal.
3. If calibrating a VDC output transducer, connect a digital
voltmeter on DC volts across the [0] and [-] terminals.
4. Apply low pressure to the transducer and carefully
adjust the zero tr immer [Z] to obtai n the desired low
output pressure.
5. Apply high pressure to the transducer and adjust the
span trimmer [S] to obtain the desired high output
pressure.
6. Repeat steps 4 and 5 until the transducer is fully
calibrated.
DIMENSIONS
Range A B C D E F G H
0.1 D
(“w.c.)
0 to
.10
-.05 to
.05
——— — — —
01 D
(“w.c.)
— — 0 to 1.0 0 to .5 0 to .25 -.5 to .5
-.25 to
.25
-.125 to
.125
05 D
(“w.c.)
——
0 to
5.0
0 to
2.5
0 to
1.2 5
-2.5 to
2.5
-1.25 to
1.2 5
-.625 to
.625
30 D
(“w.c.)
— — 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
1250 D
(pa)
——0 to
1250
0 to
625
0 to
312.5
-625 to
625
-312.5
to
312.5
-156.25
to
156.25
Shop online at: omega.com e-mail: info@omega.com
For latest product manuals: omegamanual.info
Loading...