CURRENT TRANSFORMERS
4-20 mA D.C OUTPUT

In many installations and control processes it is necessary to have a current signal between 4 and 20 mA. This signal is presently obtained by means of a .../5 A current transformer together with a 5 A / 4...20 mA converter.

NMI offers a wide range of equipments incorporating the transformer-converter single module, which that substitute the classic systems.

These converters have a current transformer consisting of an active conductor as primary winding, and a secondary winding coiled around a ferromagnetic core. All of the types have a 4...20 mA output with a frequency response that is linear between 50 and 60 Hz.

The main application of these converters is their connection to a P.L.C. They can also be used in any industrial process or control system requiring a 4...20 mA lineal current signal.

The equipments can be supplied either with direct current (10...28 V d.c.), or with alternating current (230 V a.c.) according to the selected series.

The converter output has to be supplied with a voltage between 10 and 28 V d.c. The Series has a wide range of converters with transformers of different diameters for their adaptation to any installation wires.

Measurement circuit:
• Load resistor: depending on the voltage supply (see fig. 1)

Supply circuit:
• Type: external supply of the 4...20 mA output
• Supply voltage: 10...28 V d.c.

Constructive characteristics:
• Built in a self-extinguishing, impact-resistant
• Metallic holders for easy-fitting
• Nickel plated connection terminals protected with a transparent cover
• Sealable connection terminal box at the secondary side

CURRENT TRANSFORMER WITH BUILT-IN CONVERTER
4...20 mA d.c.
(int. supply of the 4...20 mA output)
(ext. supply of the converter to 230 V a.c.)
TCB-420 Series

The converters of this Series have a supply source in an additional module. That way it is possible to directly supply the equipment from a 230 V a.c. network.

The built-in transformer has an useful circular window with several diameters according to the type.

Measurement circuit:
• Load resistor: R_L 300 W

Supply circuit: • Internal supply of the converter
• 230 V a.c. –15 % / +10 % ; 50...60 Hz
• Consumption: 0.5 VA

Constructive characteristics:
• Built in a self-extinguishing, impact-resistant
• Metallic holders for easy-fitting
• Nickel plated connection terminals