Description

Teltonika current transformer (CT) clamps are an accessory for the TeltoCharge EVC2 charging station that enables dynamic load balancing without a separate meter. They clip around the phase conductors at the supply entry and continuously tell the charger how much current the whole house is drawing at that moment. When the cooker, heat pump or other high-power appliances switch on, the charger reduces the charging current so the main circuit breaker is not exceeded. It works best when the board is near the charger – the clamp wires run straight to it.

Who needs them and who does not

The 7.4 kW and 11 kW EVC2 models are sold without clamps – for dynamic load balancing the accessory is bought separately. Most 22 kW EVC2 models (socket, socket with shutter and 5 m cable) include the clamps in the box; the 22 kW model with the 7.5 m cable (EVC2002130S0) also needs them bought separately. Balancing is also possible via Modbus RTU or Modbus TCP/IP meters, EMS or the Smartstuff P1 converter, but the clamps are the simplest route when the board is close to the charger.

Parameters set by the manufacturer

The EVC2 charger accepts only 3000:1 ratio current transformers without an integrated burden resistor. The rated current is chosen according to the supply capacity – the manufacturer recommends not exceeding 150 A, and it must be no lower than the main breaker rating. One clamp is needed per phase – three for a three-phase supply, one for a single-phase supply.

Installation and distance

Each clamp connects to its own EVC2 terminal: blue wire to B, red wire to A, and the arrow on the clamp must point towards the grid (away from the charger). Accuracy drops as the line gets longer, so the manufacturer recommends a distance to the board of up to 15 m; depending on interference it may reach 25–50 m, and with quality wiring and testing up to 100 m.

Setup in the Teltonika Energy app

In the "Load balancing" section, select the CT feature, enable balancing, tick the clamps and run the calibration – before it, the clamp is connected to the terminal but not yet placed around the cable. In the "Max grid load" field enter the supply current in amps, for example the main breaker rating. A separate support call for private charging stations is planned; the previous programme required dynamic load management.

Technical specifications

Current

According to the supply, manufacturer's recommended limit – up to 150 A

Phases

One clamp per phase

Features

3000:1 ratio, no integrated burden resistor, dynamic load balancing

Communication

Direct to EVC2 CT terminals (blue – B, red – A)

Compatibility

Teltonika TeltoCharge EVC2 (EVC20xx)

Mounting

In the distribution board on the supply lines, recommended within 15 m of the charger