Photovoltaic system: electrical equipments selection

Grid connected PV system <= 10kW (Residential)

Typically, a 5kW grid-connected single-phase inverter. with UOC MAX  600V.
One or two strings – Isctc < 25A, IAC < 32A.
In this design there is no string protection.
A PV main switch is necessary. When the inverter is indoors, an additional remote controlled switch at the DC cable entry point is recommended for emergencies services.

Needs	String junction box	PV array main switch	Inverter	AC box (400V)
Switchgears and control
Isolation \|\| • \|\| • (d) \|\| (a) \|\| • (d)
Switching (Making & breaking rated current \|\| • DC21B \|\| (a) \|\| • (d) \|\|
Control \|\| • (b) \|\| • (d) \|\| (e) \|\| • (d)
Over-current protection \|\| (c) \|\| \|\| \|\|
Protection against Insulation fault \|\| \|\| \|\| (h) \|\| (h) RCD type B or A SI
Surge protection		• type 2		• type 1 or 2
Enclosure	Outdoor IP5x Double insulation	Indoor IP5x Double insulation		Standard AC requirement + grid code requirement

Fig. P23 : 10-100kW single multi MPPT inverter