ACREL Split Core Current Transformer for Solar PV Monitoring Projects

Why Split Core CTs Are Often Used in PV Retrofit Work

Solar PV systems usually need current measurement at several points: inverter AC output, AC combiner cabinet, grid-connected cabinet, energy meter panel and sometimes the main low-voltage distribution cabinet. In these locations, the electrical cabinet may have limited space, and the wiring may already be fixed. A conventional closed-type CT may require cable disconnection, which means more labor and possible shutdown time.

The AKH-0.66/K split core design makes the installation more practical for this type of work. For EPC contractors, system integrators and O&M teams, it helps reduce installation difficulty when adding energy monitoring, power metering or remote monitoring to an existing PV system.

Typical Application Points in a Solar PV System

1. Inverter AC Output Monitoring

In a PV plant with multiple inverters, the operator may need to check the output current of each inverter. By installing split core CTs on the AC output cables, the monitoring system can collect current data from each inverter branch. This helps the user compare operating status between inverters and find abnormal conditions more quickly.

2. AC Combiner Cabinet

In distributed PV projects, several inverter outputs are often connected to an AC combiner cabinet before going to the grid-connected cabinet. Current measurement at this point is useful for branch monitoring and cabinet-level energy data collection. For cabinets that are already wired, split core CTs are easier to add than traditional closed CTs.

3. Grid-Connected Cabinet

The grid-connected cabinet is one of the key measurement points in a PV system. Current data from this cabinet can be used for energy metering, power monitoring and system operation analysis. ACREL split core CTs can be used together with Acrel power meters or monitoring devices to support this kind of data collection.

4. Existing PV Plant Upgrade

Many PV plants are not fully equipped with detailed monitoring when they are first built. After several years of operation, the owner may want to add remote monitoring, energy management, zero-export control or more detailed branch analysis. In this case, using split core CTs can make the retrofit work easier and reduce changes to the original wiring.

Product Features That Matter on Site

The AKH-0.66/K series is suitable for low-voltage current measurement applications. The product range includes different window sizes and current ratios, so it can be selected according to the cable diameter, busbar size and rated current of the measured circuit.

For cable-type installation, the AKH-0.66/K-Φ series provides compact models such as K-Φ24 and K-Φ36 and K-Φ50. These models are suitable for cable applications where the installer needs a small-size CT with convenient wiring. For projects that require small-current signal output, the AKH-0.66/K-Φ mA output series can provide output signals such as 20mA, 40mA, 50mA or other small current outputs depending on the selected model.

or busbar applications, the AKH-0.66/K series provides larger window sizes, such as 30×20, 60×40, 80×40, 100×40, 120×60, 130×50 and other specifications. This gives engineers more flexibility when selecting CTs for different distribution cabinets.

How to Select the CT for a PV Project

For a PV monitoring project, the CT should not be selected only by rated current. The engineer should also check the cable diameter or busbar size, the input requirement of the meter, the required accuracy class, and the available installation space inside the cabinet.

For example, if the CT will be connected to a multifunction power meter, the secondary output may need to be 5A or 1A. If it is used for multi-loop monitoring with a compact monitoring device, a small-current output CT may be more suitable. For an existing cabinet, the physical window size is also very important, because the CT must be able to close properly around the cable or busbar.

Suggested Use with Acrel Monitoring Devices

In solar PV applications, the split core CT is usually used together with power meters, multi-loop monitoring meters or an energy management system. A typical configuration may include split core CTs installed on inverter output cables, Acrel meters installed in the cabinet, and communication through RS485 to the monitoring platform.

This structure is commonly used when the project requires current measurement, power data collection, energy statistics and remote operation visibility. For multi-branch monitoring, the AKH-0.66/K-Φ series can be considered together with Acrel multi-loop monitoring instruments.

Installation Notes

During installation, the current direction and secondary wiring should be checked according to the product marking and manual. The CT should be fully closed after being placed around the cable or busbar. The installer should also make sure that the secondary side is connected correctly before the system is put into operation.

For PV projects, the installation environment should also be considered. The CT should be installed in a suitable electrical cabinet or indoor electrical location, away from direct rain, severe pollution and strong mechanical shock.

Conclusion

ACREL AKH-0.66/K split core current transformers are a practical choice for solar PV monitoring and retrofit projects. They are especially useful when the system is already installed and current measurement needs to be added without major changes to the original wiring.

For inverter output monitoring, AC combiner cabinets, grid-connected cabinets and existing PV plant upgrades, the split core design helps reduce installation time and makes current measurement easier to implement on site. With different current ratios, window sizes and output options, ACREL can support different PV monitoring requirements from small commercial systems to larger industrial PV projects.