Marsh Bellofram Type Transducer
Fairchild Type Transducer
Flowserve Type Transducer
EPC Type Transducer550X Electro Pneumatic Transducer
The EAA-550 series is a miniature electronic pressure regulator that converts a variable current or voltage signal into a proportional pneumatic output. It is ordered through a four-field code rather than a part number list, which makes it the flexible choice when the input, the output and the electrical connection all have to be specified.
What This Model Is
Type EAA-550 series I/P and E/P transducers are electronic pressure regulators that convert a variable signal, current or voltage, to a proportional pneumatic output. The 550X converts 4-20 mA into a 20-100 kPa pneumatic signal in its standard configuration. The small body suits DIN rail and panel work where a full-size transducer will not fit.
How It Works
Selection matters more on this instrument than on most. The 550X should be applied according to site conditions: the spring compression coefficient of the pneumatic control valve it drives has to be 20-100 kPa. Used outside that range the full-open and full-close actions of the regulating valve cannot be realised. This is different from a valve positioner, and it is why the electro pneumatic transducer has to be selected carefully rather than fitted and adjusted afterwards.
550X Electro Pneumatic Transducer On Our Benches
Studio and workshop photographs of the units as built, not renderings.
What You Get From This Model
Coded ordering covers odd combinations
Five input codes, eight output codes, three electrical connections and two options, so the unit is configured rather than compromised.
Miniature body
The smaller envelope fits panels, DIN rail assemblies and crowded valve manifolds where a full-size transducer does not.
Zero-based outputs available
Codes I, J and K give 0-30, 0-60 and 0-120 psig, which a conventional 3-15 psi unit cannot produce.
ATEX option catalogued
Option K adds ATEX approval on 4-20 mA units, with the note that it voids the FM and CSA approvals, so the trade-off is on the order form, not discovered later.
Where It Is Used
- Valve actuators with a 20-100 kPa spring range
- DIN rail mounted instrument assemblies
- Panel-mounted air pressure control
- Machine builds that need a small electronic pressure regulator
Who Orders It
- Panel builders working to a fixed enclosure size
- Machine builders fitting a modulating air stage into a compact frame
- Instrument engineers specifying an ATEX unit on a 4-20 mA loop
- Maintenance teams replacing a miniature E/P regulator
What This Model Fixes
The transducer will not fit the space left on the valve
The miniature body and the DIN rail and pipe mounting kits give three ways to mount it.
The valve never reaches full open or full close
That is a selection fault, not a calibration fault. The spring range has to sit inside 20-100 kPa for the standard unit, or the output code has to change.
Hazardous area approval is needed on one loop only
Option K adds ATEX on the 4-20 mA build without changing the rest of the specification.
Features And Specifications
Every figure below is transcribed from the datasheet EAA publishes for this series. Anything not published is not listed.
- Electronic pressure regulator, variable signal in, proportional air out
- Five input codes from 4-20 mA to 1-5 VDC
- Eight output codes from 3-15 psig to 0-120 psig
- Conduit, DIN 43650 or terminal block electrical connection
- ATEX option and 1/4 inch BSP porting option
- DIN rail and pipe mounting kits available
| Code | Input signal |
|---|---|
| A | 4-20 mA |
| C | 0-5 VDC |
| D | 1-9 VDC |
| E | 0-10 VDC |
| F | 1-5 VDC |
| Code | Output psig | Output BAR |
|---|---|---|
| C | 3-15 psig | 0.20-1.0 BAR |
| D | 3-27 psig | 0.20-1.8 BAR |
| E | 6-30 psig | 0.40-2.0 BAR |
| G | 2-60 psig | 0.14-4.0 BAR* |
| H | 3-120 psig | 0.20-8.0 BAR* |
| I | 0-30 psig | 0.00-2.0 BAR |
| J | 0-60 psig | 0.00-4.0 BAR |
| K | 0-120 psig | 0.00-8.0 BAR |
| Code | Electrical connection |
|---|---|
| A | 1/2 inch NPT conduit with pigtail |
| D | DIN 43650 connector |
| T | Terminal block |
| Code | Option |
|---|---|
| K | ATEX approvals, 4-20 mA only, voids FM and CSA approvals |
| U | 1/4 inch BSP porting |
| Accessory | Kit number |
|---|---|
| DIN rail mounting kit | Kit No. 445-766-024 |
| 1.5 inch or 2 inch pipe mounting kit | Kit No. 448-542-005 |
Output is calibrated at the factory. The large span adjustment range allows recalibration to 3-35 psig (0.2-2.4 BAR) on the 2-60 psig unit and up to 3-145 psig (0.2-10.0 BAR) on the 3-120 psig unit.
Selecting Installing And Calibrating
- Check the spring coefficient firstThe connected valve spring has to be 20-100 kPa for a standard 550X. Outside that range select a different output code.
- Build the order code550 then input, output, electrical connection and options, in that order. Each field comes from the published coding table.
- Choose the mounting kitDIN rail kit 445-766-024 for rail assemblies, pipe mounting kit 448-542-005 for a 1.5 inch or 2 inch stand pipe.
- Calibrate after mountingSet the two end points with the external adjustments once the unit is in its final position.
How It Compares With The Alternatives
Against the 500X the 550X trades the fixed part-number table for a coding system and a smaller body. The 500X suits a store that wants one catalogue number per range; the 550X suits an engineer who has to satisfy an input, an output, a termination and an approval at the same time.
| Model | Distinguishing specification | Best suited to |
|---|---|---|
| 550X Electro Pneumatic Transducer | Miniature body, four-field ordering code | Compact mounting and unusual range combinations |
| 550ACT Electro Pneumatic Transducer | 550-A-C-T built configuration | 4-20 mA to 3-15 psig with a terminal block |
| 500X Electro Pneumatic Transducer | Full-size body, fixed part-number table | Standard ranges kept as stock items |
Other Models Worth Comparing
Controlair Type Transducer500X Electro Pneumatic Transducer
Controlair pattern I/P transducer, 4-20 mA in, 3-15 to 3-120 psi out
View specifications →
Controlair Type Transducer500X Electro Pneumatic Converter
Controlair pattern E/P converter, 0-5 V, 1-9 V and 0-10 V inputs
View specifications →
Controlair Type Transducer500AC Electro Pneumatic Transducer
500-AC configuration, 4-20 mA in, 3-15 psi out, 180 ohms
View specifications →
Controlair Type Transducer500ACD Electro Pneumatic Transducer
500-AC range with a plug-in electrical termination
View specifications →Questions About The 550X Electro Pneumatic Transducer
What does the 550X convert
In its standard configuration it converts 4-20 mA into a 20-100 kPa pneumatic signal.
What happens if the valve spring is outside 20-100 kPa
The regulating valve will not reach full open and full close. The transducer has to be selected for the spring, which is different from how a valve positioner is applied.
How is the order code built
550 followed by the input signal letter, the output letter, the electrical connection letter and any option letters. For example a 4-20 mA, 3-15 psig, terminal block unit is the 550-ACT.
Can I get ATEX approval
Yes, with option K on a 4-20 mA unit. The published note is that it voids the FM and CSA approvals.
Is there a mounting kit for a pipe stand
Yes, kit 448-542-005 covers a 1.5 inch or 2 inch pipe. A DIN rail kit, 445-766-024, is also catalogued.
Request A Price For The 550X
Tell us the input signal, the output range and the electrical termination, and the quotation comes back against the published part number.