Answer:

All models of EnergyHub are designed and tested according to IEC 62109-1 and IEC 62109-2 standards, thus meeting the surge category III for AC connection and surge category II for DC connection (equivalent to a test voltage of 4 kV impulse and can therefore be likened to surge protection class III). However, these internal protections do not withstand the same currents and pulse energies as external protections. For this reason, the EnergyHub system can be supplemented with external protections if prescribed in the electrical installation regulations or if desired as additional equipment protection. For example, it may be desirable to have external protection in cases where one resides in a house or property where the risk of lightning strikes that can affect the property's electrical system is high. To investigate this further, please consult your local electrician.

The figure below shows the recommended placement in cases where the EnergyHub system is supplemented with additional surge protection.

Surge protection on the AC side of the EnergyHub

In cases where surge protection is prescribed, the AC side of the EnergyHub can be equipped with surge protection class II, connection type 2 (CT2). For example, FEEO FSP-A 4P AC SPD.

Surge protection on the direct current (DC) side of the EnergyHub

In cases where surge protection is prescribed or desired as additional protection on the DC side, surge protection class II, connection type 2 should be used. For example, ZJBENY BUD-40/3 1000V.

Surge protection at the input to Solar String Optimizers (SSOs)

Surge protection is not recommended for inputs to SSOs as it adds cost and is a potential source of failure in installations. Due to the quantity of SSOs often used, their placement, and relatively low cost, the disadvantages of surge protection outweigh the benefits. Furthermore, SSOs are designed with double insulation, just like solar panels, and can withstand 4 kV impulse relative to ground, reducing the need for external surge protection.

Surge protection for CT cabling

For Surge protection of the CT cabling, it is important that the model does not have a built-in resistor. An example of this is the OBO MCR protection 2-pole, 24V. To use these, one unit is required per CT clamp.

Other instances where surge protection may be needed

Since the EnergyHub system requires an internet connection for full functionality, surge protection may also be needed for the property's internet connection for adequate protection. This is in case your EnergyHub is connected to the internet via an Ethernet cable. For more information on this, read here or contact your internet service provider.

Surge protection may also be necessary for the CT cabling if it is laid underground or is otherwise more exposed to surges. Our recommendation is to contact companies that specialize in surge protection for further consultation.

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