The attached design is for a PV installation. We have decided to connect the PV system upstream of the main panel board, as there is no spare way available and this is the most cost‑effective option. We intend to install a junction box (JB) between the site main panel board and the DNO fuse. The JB will supply both the existing main panel board and a PV MCCB box. Since there is only one inverter, we have chosen a 4‑pole MCCB box. The existing site board is already equipped with a Type 1 SPD. However, with this arrangement, the PV system will not be protected by the existing SPD. Therefore, a separate SPD is required for the PV system.
Can the SPD be installed downstream of the PV MCCB box? I mean, can the PV MCCB provide a parallel supply to both the PV inverter and an SPD via an MCB?
