- Input
- AC current from 0-5 A to 0-3000 A, AC voltage to 500 V, DC current and voltage, with split-core and through-bore forms
- Output
- 4-20 mA, 0-20 mA, 0-10 V, 0-5 V, RS-485/Modbus or CAN
- Accuracy
- 0.2, 0.3 or 0.5 class, with plus or minus 0.1 % and 0.2 % of full scale on some forms
- Supply
- 24 V DC, 220 V AC or 12 V DC depending on the form
- Frequency range
- 50 to 400 Hz on the AC forms, with a 0-20 kHz bandwidth on the wideband form
- Power consumption
- 1.5 W or less on the one-in/one-out 220 V form
- Mounting
- DIN rail, with through-bore or split-core input
- Isolation
- Galvanic isolation between input, output and supply
A controller cannot be wired into a live feeder. A current transducer is the device that makes the measurement possible without opening the circuit: it takes the current or voltage, isolates it, and sends a standard signal to whatever is doing the reading.
The distinction that matters in a quotation is that this is not a panel meter. It has no display. It is read by a PLC, a logger or a drive, and the person who specifies it is usually the one wiring the control panel rather than the one standing at the machine.
Product overview
The device is a DIN-rail module with a through-bore or a split core for the primary conductor, screw terminals for the output and supply, and electronics that convert the measured quantity into a standard signal.
The material covers AC current from 0-5 A to 0-3000 A, AC voltage to 500 V, DC current and voltage, and three-phase power and frequency. Output is 4-20 mA, 0-20 mA, 0-10 V, 0-5 V, RS-485/Modbus or CAN, depending on the form. Supply is commonly 24 V DC, with 220 V AC and 12 V DC versions.
How a current transducer works
Three input methods appear in the material, and the difference between them is practical rather than theoretical.
A through-bore form passes the conductor through a hole in the device and senses the field around it. It is the simpler and more compact of the three, and it requires the circuit to be opened once, during installation.
A split core clamps around a cable or a busbar that is already terminated. It is what makes a retrofit possible on a 3000 A feeder, and its weakness is the joint: the two halves have to close cleanly, and a poor joint reads low rather than failing.
A direct voltage input takes the voltage across its terminals through a divider, which is why the voltage forms are rated to 500 V rather than to a current.
In every case the output is isolated from the input, which is what allows a 3000 A feeder and a 24 V control system to share an enclosure.
How to select the right transducer
AC or DC, and how many phases. A single-phase current form and a three-phase power form are different products. The three-phase form is specified by its connection — three-wire or four-wire — rather than by current alone.
Whether the circuit can be opened. This decides between through-bore and split core, and it is usually known before anything else. A retrofit on a live feeder has one answer; a new panel has the other.
Output and protocol. 4-20 mA is the default for a PLC analogue card. RS-485/Modbus or CAN is used where several parameters are read over one bus. The controller decides this, not the transducer.
Accuracy class. 0.2, 0.3 and 0.5 class are all offered. A finer class costs more and matters where the reading feeds a bill or a compliance record; for a status signal the coarser class is enough.
Installation and configuration
The module clips onto a DIN rail in the control enclosure. The primary conductor passes through the bore or sits in the split core, and the output is wired to the controller with the supply.
The practical points are the direction of the conductor, the tightness of a split core, and the separation between the primary cable and the output wiring. The material gives no wiring diagram, no torque and no clearance distances, and none is invented here.
Measurement limitations and selection considerations
The first limitation is that a transducer measures what passes through it. A conductor outside the bore, or a split core that does not close, gives a reading that is plausible and wrong.
The second is that the output is a scaled copy of the input, not a true RMS measurement on every form. The material states a frequency range of 50 to 400 Hz on the AC forms and a 0-20 kHz bandwidth on one wideband form; a distorted waveform outside that band is not represented faithfully.
The third is that several figures are missing: the isolation voltage, the enclosure rating, the ambient range and the long-term drift. They are listed as information required rather than filled in from a similar device.
Every value below is taken from source documentation. Where a parameter is not stated in the available material it is marked as information required rather than estimated.
