Answer:

Each EnergyHub, whether it's an EnergyHub Wall or an EnergyHub rack cabinet, has only one DC connection. To connect cables from SSO:s (Solar String Optimizers) and Batteries, you generally use the DC distributions provided by Ferroamp. However, for larger installations, it may sometimes be necessary to build additional DC distribution cabinets to ultimately reduce it to only one DC cable that can be connected to the EnergyHub. This may be necessary if:

• The system contains more than 15 components (SSO and batteries), or if for any other reason, we need to utilize more than 1 DC distribution from Ferroamp.
• The battery has a maximum power equivalent to a current of over 32 A, which is the maximum size of fuse that can be placed in the fuse holders in the DC distribution.
• Several EnergyHubs need to be connected in a PowerShare to share resources such as solar power and batteries between multiple grid connections.

When it comes to the design and dimensioning of DC distribution cabinets, these generally consist of terminal blocks, wiring, and MCBs (Miniature Circuit Breakers) designed for 1000 V DC and at least the maximum current that can theoretically go through the cable they are intended to break.

For instance:

• If connecting a Pylontech battery with a maximum power of 36 kW, this corresponds to approximately 47 A at a voltage of 760 V, so the MCB should be dimensioned to break at least 50 A.
• If connecting an EnergyHub Rack Cabinet 42U containing 5 EnergyHub XL 28 kW units, this corresponds to a power of 140 kW, approximately 185 A, so the MCB should be dimensioned to break at least 190-200 A.
• If connecting a DC distribution 15 with one SSO connected at each location, it can reach a maximum of 15 times 8 kW, which corresponds to 120 kW and 158 A, so the MCB should be dimensioned to break at least 160 A.

Example:

Attached is an example of a single-line diagram for the interconnection of 2 EnergyHub Rack Cabinets 42U, 3 DC distributions 15, and a Pylontech 81 kWh/36 kW battery.

We constantly want to improve the content in the Knowledge Database and would appreciate it if you give feedback on our articles. Does all the information exist, is there anything that needs to be clarified or is there any information that is missing that would help installing or using the EnergyHub system in general? You can give us feedback by choosing if the article was helpful or not in the options below. 

If you need to get in contact with Ferroamp's Technical Support or if you have any questions about the system, you can do so by creating a ticket here.