Controlair Type Transducer
Marsh Bellofram Type Transducer
Flowserve Type Transducer
EPC Type TransducerTA7800 Electro Pneumatic Transducer
The TA7800 is the T7800 built with a 1/2 inch NPT conduit fitting and pigtail, in the extended range configuration where an additional relay section amplifies the output pressure. It is the build for a field instrument that is cabled through conduit and has to deliver more than the standard output range.
What This Model Is
The TA7800 Series transducers provide maximum versatility for precision applications. The A in the model designation is the conduit and pigtail electrical connection. In the extended range build an additional relay section amplifies the output pressure, which raises what the instrument can deliver above the standard range figures while keeping the same piezoelectric primary section.
How It Works
The Model T7800 Series converts a DC input signal to a linear proportional pneumatic output. It includes the Primary Converting Section and the pneumatic Relay Section. The piezoelectric ceramic actuator in the Primary Converting Section functions as a flapper. The flapper and nozzle work together to control the signal pressure. That signal pressure acts on the upper control diaphragm in the Relay Section, and the lower control diaphragm senses the output pressure. In extended range units an additional relay section amplifies the output pressure.
TA7800 Electro Pneumatic Transducer On Our Benches
Studio and workshop photographs of the units as built, not renderings.
What You Get From This Model
Conduit entry with a flying lead
The 1/2 inch NPT conduit fitting with pigtail suits a field installation run in rigid conduit, where a plug or a terminal block would not be appropriate.
Extended range output
An additional relay section amplifies the output pressure, so the instrument reaches beyond the standard range.
Same precision core
Internal electronic feedback and the solid state controlled piezoelectric actuator give the same 0.25% full scale guaranteed accuracy as the rest of the family.
Certified enclosure
NEMA 4X, Type 4, IP65 rated for indoor and outdoor installations, with CRN certification for all Canadian territories and provinces.
Where It Is Used
- Field instruments run in rigid conduit
- Extended range pressure control on large actuators
- Outdoor installations rated NEMA 4X and IP65
- Split range control from a common signal source
- Precision loops where a flying lead is the required termination
Who Orders It
- Contractors installing to a conduit standard
- Plants needing extended range output on a precision instrument
- Instrument engineers specifying CRN-certified equipment for Canada
- Maintenance teams replacing a pigtail-terminated transducer
What This Model Fixes
The installation standard requires conduit
The A build terminates in a 1/2 inch NPT conduit fitting with a pigtail rather than a plug or a block.
Standard range output is not enough
The extended range build adds a relay section that amplifies the output pressure.
Accuracy cannot drop when the range goes up
The piezoelectric primary section and internal electronic feedback are common to the family, so the ISA accuracy figures are unchanged.
Signal failure behaviour has to be known
The field reversible feature provides an output inversely proportional to the input signal where the loop requires it.
Features And Specifications
Every figure below is transcribed from the datasheet EAA publishes for this series. Anything not published is not listed.
- 1/2 inch NPT conduit fitting with pigtail
- Extended range: additional relay section amplifies the output pressure
- Field reversible output, inversely proportional to the input signal
- RFI and EMI protection
- Internal electronic feedback with a solid state controlled piezoelectric actuator
- Damping adjustment for optimum tuning response
- Split range operation from a common signal source
- Compact size for restricted spaces
- NEMA 4X, Type 4 enclosure, IP65 rated for indoor and outdoor installation
- Canadian Registration Numbers (CRN) certification for all territories and provinces
| Set point | 3 psig [0.2 BAR] (20 kPa) | 9 psig [0.6 BAR] (60 kPa) | 15 psig [1.0 BAR] (100 kPa) | 30 psig [2.0 BAR] (200 kPa) |
|---|---|---|---|---|
| Maximum air consumption, all ranges | 3.5 SCFH (0.10 m3/HR) | 7.0 SCFH (0.20 m3/HR) | 9.5 SCFH (0.27 m3/HR) | 13.5 SCFH (0.38 m3/HR) |
| Range | Low | Middle | High |
|---|---|---|---|
| Output range | 3-15 psig [0.2-1.0 BAR] (20-100 kPa) | 3-27 psig [0.2-1.8 BAR] (20-180 kPa) | 6-30 psig [0.4-2.0 BAR] (40-200 kPa) |
| Supply pressure | 20-120 psig [1.5-8.0 BAR] (150-800 kPa) | 32-120 psig [2.2-8.0 BAR] (220-800 kPa) | 35-120 psig [2.4-8.0 BAR] (240-800 kPa) |
| Minimum span | 5 psig [0.35 BAR] (35 kPa) | 10 psig [0.7 BAR] (70 kPa) | 10 psig [0.7 BAR] (70 kPa) |
| Parameter | Value |
|---|---|
| Input range | 4-20 mA DC, 0-10 VDC, 1-9 VDC |
| Flow rate | 2.5 SCFM (4.25 m3/HR) at 25 psig [1.7 BAR] (170 kPa) supply and 9 psig [0.6 BAR] (60 kPa) output, or 9.0 SCFM (15.3 m3/HR) at 120 psig [8.0 BAR] (800 kPa) supply and 9 psig output |
| Accuracy (ISA S51.1) | 0.25% full scale guaranteed, 0.15% full scale typical |
| Hysteresis (ISA S51.1) | 0.1% full scale |
| Deadband | 0.02% full scale |
| Repeatability (ISA S51.1) | 0.1% full scale |
| Frequency response | -3 dB at 5 Hz per ISA S26.4.3.1 load configuration A |
| Operating temperature | -40 F to +160 F (-40 C to +71.2 C) |
| Storage temperature | -40 F to +180 F (-40 C to +82.2 C) |
| Required operating voltage | Two-wire current input 7.2 VDC at 20 mA (4-20 mA signal); three-wire voltage input 7.2-30 VDC, less than 3 mA |
| Signal impedance | Three-wire voltage input 10 kilohms |
| Span and zero adjustment | Screwdriver adjustments located on the front of the unit |
| Position effect | No measurable effect |
| Supply pressure effect | No measurable effect |
| Temperature effect | +0.5% +0.04% per F temperature change of span, typical |
| Vibration effect | Less than +/-1% of span at 5-15 Hz with 0.8 inch constant displacement and 15-500 Hz at 10 G |
| Reverse polarity protection | No damage from reversal of normal supply current (4-20 mA) or from misapplication of up to 60 mA |
| RFI / EMI effect | Less than 0.5% of span at 30 V/m class 3 band ABC (20-1000 MHz) per SAMA PMC 33.1 1978, and less than 0.5% of span at 10 V/m to 2 GHz per EN 61000-4-3:1998 +A1, EMC Directive 89/336/EEC, European norm EN 61326 |
| Component | Material |
|---|---|
| Body and housing | Chromate treated aluminium |
| Orifice | Nickel plated brass and sapphire |
| Trim | Stainless steel, brass and zinc plated steel |
| Elastomers | Nitrile |
| Model | Electrical connection and range |
|---|---|
| TT7800 | Terminal block. Available in standard range and extended range. |
| TA7800 | 1/2 inch NPT conduit fitting with pigtail. Available in extended range. |
| TD7800 | DIN 43650 connection. Available in standard range and extended range. |
| TR7800 | For use with the TR manifold rack kit. Same as the TT7800 except that the terminal block is located on the rear. Available in standard and extended range. |
Selecting Installing And Calibrating
- Check the supply against the output range20-120 psig for 3-15 psig output, 32-120 psig for 3-27 psig and 35-120 psig for 6-30 psig, in the standard range. Extended range units amplify above this.
- Terminate the pigtail properlyLand the flying lead in a junction box outside the instrument and keep the conduit seal intact so the enclosure rating is maintained.
- Adjust from the frontSpan and zero are screwdriver adjustments on the front of the unit.
- Verify the reverse acting directionIf the loop needs inverse action, confirm it before commissioning rather than after the valve moves the wrong way.
How It Compares With The Alternatives
TA7800, TT7800, TD7800 and TR7800 are the same instrument with different electrical connections: conduit pigtail, terminal block, DIN 43650 and rear-terminal rack mount. Choose on how the installation is wired, then choose standard or extended range on how much output the final element needs.
| Model | Distinguishing specification | Best suited to |
|---|---|---|
| TA7800 Electro Pneumatic Transducer | Conduit fitting with pigtail, extended range | Conduit-wired field installations |
| TT7800 Electro Pneumatic Converter | Terminal block | Cabled installations landed on terminals |
| TD7800 Electro Pneumatic Transducer | DIN 43650 connection | Plug-in terminations |
Related cases
- No OEM case published for this model yet.
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View specifications →Questions About The TA7800 Electro Pneumatic Transducer
What does the A in TA7800 mean
It is the electrical connection: a 1/2 inch NPT conduit fitting with a pigtail.
What is the extended range build
A version in which an additional relay section amplifies the output pressure, so the instrument delivers above the standard range figures.
Is the accuracy the same as the standard range unit
The piezoelectric primary section and the internal electronic feedback are common to the T7800 family, which is specified at 0.25% full scale guaranteed to ISA S51.1.
Can it be used outdoors
Yes. The enclosure is NEMA 4X, Type 4 and IP65 rated for indoor and outdoor installations.
Does it have reverse polarity protection
Yes. No damage occurs from reversal of the normal supply current or from misapplication of up to 60 mA.
Request A Price For The TA7800
Tell us the input signal, the output range and the electrical termination, and the quotation comes back against the published part number.