ETA3.RTU - 3 Phase Current Transducer /w RS485 Output

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ETA3.RTU - 3 Phase Current Transducer /w RS485 Output

Features:

True RMS, accurate measurements.
RS485 Communication.
Easily addressable (up to 63 devices).
Supports inexpensive current transformers (MCT or MSCT) and standard 5 A CTs.
Compact Size, Easy Wiring, DIN Rail Mounting.
Ideal for Control and Energy Management Applications.

Application:

The ETA3.RTU transducer offers inexpensive yet accurate true RMS monitoring of AC current in three independent circuits or one 3 phase circuit.

This unique product is ideal as a precision AC load transducer for Control and Energy Management applications.

The ETA3.RTU combined with inexpensive current transformers provides a convenient tool for accurate load monitoring in any electrical equipment.

Product Description:

The ETA3.RTU is a microprocessor based precision current transducer that performs true RMS current measurements in one three phase circuit or in three independent AC circuits.

The unit supports standard current transformers (5A or 1A) as well as a variety of inexpensive current sensors which provide safe mV signals (no shunts necessary). These sensors include split and solid core CTs as well as precision current sensors that may be applied to the secondary wires of the existing 5 A CTs.

The ETA3.RTU measures true RMS current in each of the three inputs and provides output data (via RS485 port) that is proportional to the RMS current in each input and to the averaged current {Iavg= (I1+I2+I3)/3}. The transducer supports Modbus RTU protocol (please refer to the Communications Protocol Sheet for more information on communication requirements).

The ETA3.RTU is powered by 24 VAC/VDC and a small, (for AC excitation, a small dedicated Class 2 transformer is recommended). The unit is housed in a small plastic enclosure equipped with universal DIN mounting attachment.

The ETA3.RTU-Display may be used instead of a dedicated Modbus Master to graphically display the readings from up to six ETA3.RTU modules. Contact Elkor for more details.

Specifications:

Power Req.:	24 VDC/VAC, 2 VA
Current Inputs:	Standard CTs, 5A or 1A Elkor Current Transformers (solid/split core — MCT/MSCT): mV output CTs (1000mV or 333mV)
Output:	RS485 digital communication port. Up to 63 devices may be served by one line. 9600, N, 8, 1, Modbus RTU protocol.
Accuracy:	TRMS, 0.5% FS
Temperature Range:	Standard: 0-70°C Industrial: -40°C to 80°C, conformal coated.
Mounting:	DIN Rail - universal DIN attachment mounted on the back of enclosure; dimensions h=3.75" w=2" d=2.25" (95x50x60mm).

Ordering Information:

ETA3.RTU-[1]-[2]

Where:
[1] Specifies CT Input Type:

	5A	Inputs for 5A CTs
	MCTA	Inputs for MCTA CTs (full scale current must follow, up to 300A)
	MSCT1	Inputs for MSCT1 CTs (full scale current must follow, up to 200A)
	MSCT2	Inputs for MSCT2 CTs (full scale current must follow, up to 600A)
	MSCT3	Inputs for MSCT3 CTs (full scale current must follow, up to 1500A)
	333mV	Inputs for 333mV CTs
	1000mV	Inputs for 1000mV CTs
	*** Contact Elkor for other input options

[2] Specifies desired Full Scale Calibration (Amps). (N/A for 5A)

Example:

ETA3.RTU-MSCT1-100A

Specifies transducer with MSCT1 CTs. Output Full Scale = 100A

Information:

Datasheet	PDF
Communications Protocol	PDF
App. Note AN0302 - RS485 Modbus Addressing	PDF
App. Note AN0303 - Modbus Troubleshooting	PDF
App. Note AN0305 - Introduction to Current Transformers	PDF
Wiring Diagram	PDF	GIF