Legrand 4 120 42 & 4 120 43 3-Phase CT Energy Meter

Product Overview and Safety Precautions

⚠️ Important Safety Warning: Failure to strictly observe installation and use conditions may lead to risks of electric shock or fire.

This document provides technical and installation information for the Legrand 3-phase Current Transformer (CT) operated energy meters, models 4 120 42 and 4 120 43. These meters are designed for accurate energy measurement in three-phase electrical systems.

Key Specifications:

• Voltage Input: 3x100V to 3x400V (Phase-to-Phase) or 3x100/173V to 3x230/400V (Phase-to-Neutral)
• Current Input: Via CTs (requires 5A secondary current rating)
• Frequency: 50-60 Hz
• Operating Temperature: -25°C to +55°C
• Metering Accuracy: 0.1 Wh/imp (Watt-hour per impulse)
• Communication: RS485 Modbus
• Electrical Safety Classification: CAT III
• Conformity Standards: EN 50470-1:2006, EN 50470-3:2006

Terminal Identification:

The meters feature clearly labeled terminals for various functions:

• Power Input: L1, L2, L3, N (for auxiliary power supply)
• Measurement Input: V1, V2, V3, N (for voltage measurement, used in conjunction with CTs for current measurement)
• Output Terminals: For pulse output (e.g., 1 C, E, SG)
• Communication Terminals: RS485 (+, -, SG)
• Auxiliary Power: 12/24V d.c. terminals

Lead Sealing:

Designated positions are available for lead sealing to ensure the integrity of the installation.

Wiring Configurations

The following diagrams illustrate typical wiring setups for the Legrand 4 120 42/4 120 43 meters. Ensure appropriate protective fuses (e.g., F:0,5A gG) are installed.

3-Phase, 3-Wire (3N-3E) Configuration:

This configuration connects the three phase lines (L1, L2, L3) and potentially the neutral (N) for power and voltage measurement inputs. The diagrams show connections to voltage terminals (V1, V2, V3, N) and other functional terminals (e.g., 2, 5, 8, 11).

3-Phase, 3-Wire (3-3E) Configuration:

This diagram details wiring for a 3-wire system, focusing on phase connections for measurement.

3-Phase, 2-Wire (3-2E) Configurations:

Two variations are presented for 3-2E systems, showing different phase connections for voltage inputs (e.g., between L1-L2 or L1-L3).

Load Connection: Terminals are provided for connecting the electrical load.

Communication Interface (RS485/Ethernet)

The meters support data communication via the RS485 interface, typically utilizing the Modbus protocol. An Ethernet connection is also an option for network integration.

RS485 Wiring:

The RS485 interface uses dedicated terminals for data transmission (+, -, SG). The diagrams illustrate a daisy-chain connection for multiple devices on a network.

• Recommended Cables: For optimal performance, use Belden 9842, Belden 3106A (or equivalent) for bus lengths up to 1000 meters. For shorter distances up to 50 meters, Category 6 (FTP or UTP) cable is suitable.
• Termination Resistor: A termination resistor is recommended for RS485 bus stability. Note that this resistor is not supplied with articles 4 120 42 and 4 120 43.

Modbus Configuration Parameters:

To establish communication, configure the following Modbus parameters:

• Modbus Address: The default address is 5.
• Baud Rate: Set to 19.2 kbps.
• Parity: Configure for Even parity.

EU Declaration of Conformity

Legrand, located at 128, Avenue du Maréchal de Lattre-de-Tassigny, 87045 LIMOGES CEDEX, FRANCE, hereby declares under its sole responsibility that the product:

• Trade Mark: LEGRAND
• Designation: Compteur tri-phase CT 4M 5A - MID / 3-phase CT meter 4M 5A - MID
• Product Codes: 4 120 42, 4 120 43

This product is in conformity with the relevant Union harmonisation legislation, including:

• Directive 2014/35/EU (Low Voltage)
• Directive 2014/30/EU (Electromagnetic Compatibility)
• Directive 2014/32/EU (Measuring Instrument)
• Directive 2011/65/EU (ROHS 2) as amended by 2015/863

The conformity is ensured through adherence to the following standards:

• EN 50470-1:2006
• EN 50470-3:2006

The product described herein matches the product detailed in the EU type examination certificate N° 0120/SGS0446, issued by the Notified Body 0598. This declaration certifies that the essential requirements of Annex I and relevant specific annexes have been demonstrated.

Further Documentation

The complete documentation for these Legrand products is available on the official e-catalogue website. Please visit www.e-catalogue.legrandgroup.com and search for "4 120 42 - 4 120 43".