SMA EM-1CT63A-21 Energy Meter (Smart Meter)

The SMA Energy Meter CT EM-1CT63A-21 is a smart energy meter designed to quickly and accurately record electrical flows in photovoltaic installations and SMA energy management systems. This version includes a 63 A current transformer and can transmit measured values via Ethernet within the local network, making it easier to monitor grid consumption, exported energy, and photovoltaic generation.

Thanks to its bidirectional measurement, the SMA EM-1CT63A-21 can determine both energy imported from the grid and energy fed into it. This information can be used within the SMA ecosystem to optimize energy management, increase the use of photovoltaic energy, and perform control functions compatible with the installed equipment.

Measurement with 63 A current transformer

The SMA EM-1CT63A-21 measures energy using a current transformer, included as standard with the device. This version features a CT connection and is intended for single-phase applications with a maximum current limit of up to 63 A.

Unlike other meters with direct connection, the SMA Energy Meter CT records current via the corresponding transformer. This setup makes it easier to integrate into electrical panels and allows measurement without routing the full installation current directly through the meter itself.

Bidirectional measurement for photovoltaic installations

The SMA Energy Meter CT can record energy flows in both directions. In this way, it can be used to determine the power consumed from the grid and the photovoltaic power exported to the grid.

It can also be used as a photovoltaic generation meter and help integrate the output of inverters from other manufacturers into certain compatible SMA energy management systems.

Communication via Ethernet

The meter includes an Ethernet interface to transmit recorded values over the local network. It does not have WiFi connectivity, so integration with the other system components is carried out via network cable.

Fast communication of electrical values allows compatible SMA systems to have up-to-date information for monitoring and energy management. The manufacturer provides measurement cycles of 1000 ms and 200 ms.

Compatible with SMA energy management systems

The SMA EM-1CT63A-21 is designed to integrate into installations with SMA management systems. It can be used together with Sunny Home Manager 2.0 and compatible System Manager solutions, providing the values needed to monitor and manage the installation’s energy flows.

SMA also includes this meter among the compatible components for certain zero-export configurations. In these systems, the information provided by the meter allows the control system to know the energy exchange at the grid connection point in real time.

Compact DIN rail installation

The device is designed for DIN rail installation inside an electrical panel or meter cabinet. Its dimensions are only 35 x 88 x 65 mm and it occupies two DIN rail modules, making it easy to integrate even in panels with limited available space.

The EM-1CT63A-21 model has an approximate weight of 0.2 kg and is designed to operate at ambient temperatures between -25 and +55 °C.

Accuracy and low consumption

The SMA Energy Meter CT offers measurement accuracy of up to ≤ 2% and supports a maximum current of 63 A via the supplied transformer. Its maximum own consumption is ≤ 2 W, helping keep the auxiliary consumption of the monitoring system low.

The nominal operating voltage is between 85 and 250 V AC and it supports grid frequencies of 50 or 60 Hz with a tolerance of ±5%.

Technical specifications of the SMA EM-1CT63A-21

• Brand: SMA Solar.
• Reference: EM-1CT63A-21.
• Range: SMA Energy Meter CT.
• Type: smart energy meter / Smart Meter.
• Application: energy measurement and management in photovoltaic installations.
• Number of current transformers included: 1.
• Current limit: maximum 63 A.
• Measurement type: current transformer.
• Bidirectional measurement: yes.
• Nominal voltage: 85-250 V AC.
• Frequency: 50/60 Hz (±5%).
• Maximum own consumption: ≤ 2 W.
• Measurement accuracy: ≤ 2%.
• Measurement cycles: 1000 ms / 200 ms.
• Communication interface: Ethernet.
• WiFi: no.
• Mounting: DIN rail in electrical panel or meter cabinet.
• DIN rail space required: 2 modules.
• Dimensions: 35 x 88 x 65 mm.
• Weight: approximately 0.2 kg.
• Operating ambient temperature: -25 to +55 °C.
• Transport and storage temperature: -25 to +70 °C.
• Maximum operating altitude: 2000 m above sea level.
• Degree of protection: IP20.
• Protection class: II.
• Overvoltage category: CAT III.
• Manufacturer warranty: 2 years.

Scope of delivery

According to SMA documentation, the EM-1CT63A-21 package includes the SMA Energy Meter CT itself, a 63 A current transformer, the connector for the voltage input, the connector for the current transformer, and the installation documentation.

Measurement to optimize photovoltaic self-consumption

The information provided by the SMA EM-1CT63A-21 makes it possible to see how energy flows between the photovoltaic system, the loads, and the grid. Integrated into a compatible SMA system, this data can be used to optimize self-consumption, monitor energy purchased or exported, and coordinate energy management strategies.

Its compact DIN rail format, Ethernet communication, bidirectional measurement, and included 63 A current transformer make the SMA Energy Meter CT EM-1CT63A-21 a dedicated solution for single-phase installations that need to add energy metering to the SMA ecosystem.

Important: installation and commissioning of the meter must be carried out by qualified personnel and in accordance with the instructions and safety requirements established by SMA.