Current Transformers (CTs) can be organised into groups to aggregate their readings. This functionality is particularly useful for monitoring multiple solar PV systems and displaying their total generation. The grouping of CTs is configured via the CT Config menu, where you can assign each CT to a specific group.
Warning: Different CT Types cannot coexist in the same group; this is clearly indicated by the group names. Additionally, only the first four groups are eligible for current limiting, as explained below.
Setting Group Limits
Group limits are a crucial feature for managing power consumption within specified parameters. When a group limit is set, the myenergi devices within that group will regulate the power they draw to remain within the defined limit.
Group limits should only be configured on the master device. It is possible to implement more than one type of group limit concurrently (e.g., IL1 with MN1), thus allowing multiple conditions for limiting power usage.
Below are some examples of how to effectively set up group limits:
Example Configurations for Group Limits
Scenario 1: Limiting Current Drawn by Two zappi Devices on the Same 32A Supply
- Additional CT Installed: None; only the internal CTs are used.
- CT Config (all devices):
- CT Type: Internal
- Group: IL1
- Group Limit: 32A
Scenario 2: Limiting Current Drawn by a zappi Device on a 32A Supply Also Feeding Another Appliance (e.g., a Tumble Dryer)
- Additional CT Installed: One CT is clipped around the live wire of the 32A supply and wired to CT2 of the zappi.
- CT Config:
- CT2 Type: Monitor3
- Group: MN1
- Group Limit: 32A
Scenario 3: Limiting Current Drawn by Two zappi Devices in a Garage Fed by a 40A Supply (Also Powers a Washing Machine and Dryer)
- Additional CT Installed: One CT is clipped around the live wire of the 40A supply to the garage and wired to CT2 of one of the zappi units. Note: The other zappi does not require a CT connection, but it must have a CT input configured to be in the same Monitor group.
- CT Config:
- CT2 Type: Monitor
- Group: MN1
- Group Limit: 40A
Conclusion
Organising CTs into groups and setting appropriate group limits are essential for efficient energy management in various setups. By following the outlined configurations, users can ensure that their myenergi devices operate within safe and efficient parameters, maximising the benefits of their energy systems.