Victron VM-3P75CT Energy Meter: Setup & Wiring Guide

Key Takeaways

• The Victron VM-3P75CT (part number VM-3P75CT REL200300100) is an advanced three-phase energy meter with a Rated current 75 A per phase.
• Accommodates wide AC grid inputs: Input voltage range L-N 85 to 265 VAC and Input voltage range L-L 150 to 460 VAC (50/60 Hz).
• Equipped with 3x split-core current transformers featuring Current connection Via current transformers (included - wire length 640 mm (25,2in) for non-invasive installation.
• Provides high-speed telemetry over VE.Can communication port Two RJ45 connectors (VE.Can terminators included) or Ethernet communication port One RJ45 connector, Modbus UDP.
• Delivers an ultra-fast Refresh rate 100 ms, enabling real-time Energy Storage System (ESS) zero-export control and load compensation.
• Operates using Type Self-power supply via L1-N with low power draw: Consumption 1,45 W / 3,1 VA.
• Compact DIN-rail form factor with Dimensions 90 x 71 x 59 mm (3,5 x 2,8 x 2,3 in) Weight 370 g and Operating temperature From -10 to +55 °C.

Hardware Overview & Power Connection

The Victron VM-3P75CT provides real-time energy metering for grid-tied, off-grid, and ESS storage installations. By broadcasting power values at high speeds over VE.Can or Ethernet, it eliminates the measurement latency common to older RS485 Modbus RTU meters.

The Victron VM-3P75CT is a three-phase energy meter (part number VM-3P75CT REL200300100) accepting 85-265 VAC L-N and 150-460 VAC L-L (50/60 Hz) voltage inputs, self-powered via L1-N terminals (consumption: 1,45 W / 3,1 VA):

• Current Sensing: 3x Split-Core CTs, Rated Current 75 A, Wire: 640 mm Length.
• VE.Can Port (RJ45): 2x RJ45 Sockets, 250 kbit/s Speed, Terminators Incl.
• Ethernet Port: 1x RJ45 Port, Modbus UDP, 100 ms Rate.

When wiring the meter:

1. Line Voltage Wiring: Connect L1, L2, L3, and Neutral to the top screw terminals. The meter utilizes a Type Self-power supply via L1-N, meaning L1 and Neutral must be energized for the meter to operate. Ensure an external 2-pole or 4-pole disconnecting circuit breaker protects the voltage sensing leads.
2. Voltage Ranges: The meter accepts Input voltage range L-N 85 to 265 VAC and Input voltage range L-L 150 to 460 VAC, making it suitable for both single-phase and three-phase grid topologies.
3. Physical Dimensions: Sized at Dimensions 90 x 71 x 59 mm (3,5 x 2,8 x 2,3 in) Weight 370 g, the unit occupies 4 DIN modules in standard distribution boards.

Split-Core Current Transformer Installation

The VM-3P75CT includes 3 pre-wired split-core current transformers for measuring AC line currents without disconnecting main distribution cables:

• CT Specifications: Each transformer is calibrated for a Rated current 75 A with pre-wired leads measuring Current connection Via current transformers (included - wire length 640 mm (25,2in).
• Orientation & Matching: Each CT is marked to correspond with its respective phase input terminal (L1, L2, L3). An arrow printed on the clamp body indicates orientation; ensure the arrow points towards the loads (away from the grid).
• Safety Warning: Never install current clamps on bare uninsulated copper busbars or damaged conductors.

VE.Can & Ethernet Modbus UDP Networking

The VM-3P75CT provides dual networking paths to communicate with Cerbo GX, Ekrano GX, and Venus OS devices:

With a Refresh rate 100 ms, the VM-3P75CT delivers instantaneous power readings to the MultiPlus-II or Quattro inverter/charger, ensuring sub-second response times for ESS dynamic zero-export and phase balancing.