Electrical & Thermal Transducers
True RMS to 4-20 mA, with channel-to-channel isolation.
A PLC analog input does not care how the measurement was made, only that the signal arriving is the truth. That is the whole job of a transducer, and it is where an average-responding device quietly fails: on a distorted waveform it reads low, and the control system acts on a number that was never correct. These transducers measure true RMS, along with peak value and harmonics to the 11th order, at better than 0.2% accuracy over 5% to 100% of span.
AC input runs up to 380 V and DC input up to 400 V, with 0–10 VDC, 0–20 mA or 4–20 mA output, 100–240 V supply at 45 mA and 35 mm DIN rail mounting. Channel-to-channel isolation is provided for safe operation in severe electrical environments, which is what makes them usable on MV-derived signals feeding a shared PLC rack. The range extends to a four-channel thermal protection relay for transformer and panel temperature protection.
Why it matters
True RMS measurement means the SCADA value matches the real quantity on a distorted waveform, where an average-responding transducer under-reads.
Channel-to-channel isolation lets several circuits share a rack without one fault propagating across the analog inputs.
Better than 0.2% accuracy across 5% to 100% of span keeps the signal usable at light load, not only near full scale.
0–10 VDC, 0–20 mA and 4–20 mA outputs cover the analog input cards already installed, so a retrofit does not force a controller change.
The four-channel thermal protection relay adds 10 programmable relay outputs with Modbus TCP/IP, DNP3.0 and Bluetooth, so temperature protection joins the same data path.
Ratings
AC input: Up to 380 V
DC input: Up to 400 V
Outputs: 0–10 VDC, 0–20 mA or 4–20 mA
Supply: 100–240 V, 45 mA, 50/60 Hz
Accuracy: <0.2%
Operating range: 5% to 100% of span
Measurement: True RMS, peak value and harmonics to the 11th order
Isolation: Channel-to-channel isolation for safe operation in severe electrical environments
Mounting: 35 mm DIN rail
Extended range
Four-channel thermal protection relay: Up to 4 temperature channels with 10 programmable relay outputs, 24 VDC / 240 VAC supply, <0.5% current and <0.2% voltage uncertainty, Modbus TCP/IP, DNP3.0, Bluetooth and optional Wi-Fi, non-volatile event memory.
Standards
IEC 61010-1
IEC 61326-1 EMC
Applications
Feeding PLC and SCADA analog inputs from MV circuits
Retrofitting analog instrumentation to digital control
Transformer and panel temperature protection
Harsh industrial environments needing galvanic isolation
Questions engineers ask
Why does true RMS matter in a transducer?An average-responding transducer is calibrated on a sine wave, so once the current is distorted by drives, rectifiers or LED loads it reads low. A true RMS transducer measures the heating-equivalent value directly, which is the quantity your protection settings, cable ratings and energy calculations are actually based on.
What does channel-to-channel isolation protect against?It keeps each measurement channel electrically separate from the others and from the output, so a fault or a large potential difference on one circuit does not propagate through the shared analog wiring into the PLC. That is the condition to look for when several MV-derived signals land on one controller rack in a harsh environment.
Technical documentation
Download HVEX Electrical and Thermal Transducers datasheet (English, PDF)
