PX154 SERIES 1-800-TC-OMEGA
Pressure Transducer CE OMEGA
An OMEGA Technologies Company
One Omega Drive, Box 4047, Stamford, CT 08907
Output: 4-20 mA, 2-Wire Loop Telex 996404 Cable OMEGA FAX (203) 359-7700
TERMINATION SCHEDULE PRESSURE TRANSMITTER BOARD LAYOUT
24 Vdc power 4-20 mA, 2-wire, Field ZERO SPAN
4-20 mA, 2-wire loop signal Conversion to 1-5 Vdc Signal | [] [Is]
(© +24 Vde (1) +24 Vde
H L
O 4-20 mA signal out 3 le hm fi
ohms
© No connection ©
Common
Gauge (Positive) Pressure Sensing
Connect media pressure to port labeled "HIGH", with port labeled "LOW" vented to atmosphere.
Negative (Vacuum) Pressure Sensing
Connect media pressure to port labeled "LOW", with port labeled "HIGH" vented to atmosphere.
Differential Pressure Sensing
Connect the higher of the two media pressures to port labeled "HIGH" and the lower of the two pressures to port labeled
"LOW",
Port Connections - 1/8" NPT female. (ALWAYS USE A SECOND WRENCH TO HOLD THE PORT HEX NUT, THEREBY
Mi T BILITY T T FITTING.)
Mounting
Transducer can be operated in any position; however, be alert to moisture passing through non-waterproof electrical
connectors.
Media Compatibility
"HIGH" port - Pasitive or high pressure port.
30% Glass-filled Polyester, Silicon, Buna-N, Vinyl tubing, Brass or 316 S.S. port fittings.
"LOW" port - Negative or low pressure port.
Calibration 30% Glass-filled Polyester, Silicon, Fluorasilicone, Vinyl tubing, Brass or 316 S.S. port fittings.
The Zero and Span may be adjusted if necessary or desirable; however, the requested full scale range as shipped is
established with fixed resistors minimizing the range of the adjustment pots.
The average full scale adjustability is approximately +10% of the range shipped.
Minimum Pressure Operation - (After applying power, allow approximately 20 - 30 minutes for signal to stabilize)
When operating at low differential pressures of less than 5" W.C. or in applications where the pressure is fluctuating
rapidly, it is advisable to insert "snubbers" or air flow restrictors in the input lines. This "steadies™ the output signal and
keeps it from bouncing erratically.
Adjustments
The transducers are adjusted for the specified range at the factory and should require no further adjustments.
"7" - Zero control is adjusted for 4 mA output (or 1 volt) signal at O psi, or minimum pressure.
"5" - Span contro! is adjusted to change the full scale range of the transducer.
Due to resistor values required to compensate for the null off-set of the sensing module, evidence of Zero and Span
interaction may be experienced in re-adjusting.
M805/038
October 1994
SPECIFICATIONS @ 24 Vdc and 25°C
Excitation 18 Vdc to 30 Vdc
Linearity and Hysteresis +0.1% FS
Zero and Span Adjustments + 10% FS
100% Relative Humidity Non-condensing
Temperature Zero and Span Effects See Figure 1
Shock Resistance 50G, 11ms, Half Sine
Vibration 10 to 2000 Hz @ 100 Sine
Figure 1
Non-Temperature Compenseted Accuracy wd
(All Output Signals) I — — 00
Accuracy with Temperature Shift _ +
Span from 26°C Ambient (% FS) E 1
E 5°C + 10°C + 25°C O
= 700 <= = == == = — —
0-27.7"wc | +.11% + .32% + 1.00% 3 A <
0-26.0"WC 12 36 1.10 $ + Operating
= Region
0-10.0"WC .30 .80 2.28 © 400 — N
0-5.0 "WC ‚60 1.80 5.54 $ T DN
0-3.0 "WC | 1.00 3.00 9.23 - 1
0-10 "we | 300 9.00 27.70
18 19 20 21 22 23 24 25 26 27 28 29 30
To determine accuracy for spans not shown: Supply Voltage
22.YWE x Factors shown above for 0-27" span
FS Range and temperature column selected.
WARNING!
READ BEFORE INSTALLATION
Fluid hammer and surges can destroy any pressure transducer and must always be avoided. A pressure snubber should be installed
to eliminate the damaging hammer effects.
Fluid hammer occurs whan a liquid flow is suddenly stopped, as with quick closing solenoid valves. Surges occur when flow is suddenly
begun, as when a pump is turned on at full power or a valve is quickly opened.
Liquid surges are particularly damaging to pressure transducers if the pipe is originally empty. To avoid damaging surges, fluid lines
should remain full (if possible), pumps should bs brought up to power slowly and valves opened slowly. To avoid damage from both
fluid hammer and surges, a surge chamber should be installed and a pressure snubber should be installed on every transducer.
Symptoms of fluid hammer and surge’'s damaging effects:
a) Pressure transducer exhibits an output at zero pressure {large zero offset). If zero offset is less than 10% FS, user can
usually re-zero meter, install proper snubber and continue monitoring pressures.
b) Pressure transducer output remains constant regardiess of pressure.
с} in severa cases, there will be no output.
WARRANTY
OMEGA warrants this unit to be free of defects in matsrials and workmanship and to gibe satisfactory service for a period of 13 months from date of purchase.
OMEGA Warranty adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping time. This ensures
that our customers receive maximum coverage on each product. if the unit should malfunction, KE must be retumad ta the factory for evaluation. Our Customer
Service Department will issue an Authorized Return (AR) number immediately upon phone or written request. Upon examination by OMEGA, if the unit is
found to be defective it will be repaired or replaced at no charge. However, this WARRANTY is VOID if the unit shows evidence of having besn tampered
with or shows evidence of being damaged as a result of excessive current, hear, moisture, vibration or misuse. Components which wear or which are damaged
by misuse are not warranted. These include contact points, fuses and triacs.
THERE ARE NO WARRANTIES EXCEPT AS STATED HEREIN. THERE ARE NO OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED
TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND OF FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL OMEGA ENGINEERING, INC.
BE LIABLE FOR CONSEQUENTIAL, INCIDENTAL OR SPECIAL DAMAGES. THE BUYER'S SOLE REMEDY FOR ANY BREACH OF THIS AGREEMENT BY OMEGA
ENGINEERING, INC. OR ANY BREACH OF ANY WARRANTY BY OMEGA ENGINEERING, INC. SHALL NOT EXCEED THE PURCHASE PRICE PAID BY THE
PURCHASER TO OMEGA ENGINEERING, INC. FOR THE UNIT OR UNITS OR EQUIPMENT DIRECTLY AFFECTED BY SUCH BREACH.
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