UNE-EN 60904-3:2016

This Standard sets out design requirements for photovoltaic (PV) arrays including d.c. array 199 wiring, electrical protection devices, switching and earthing provisions. The scope includes all 200 parts of the PV array up to but not including energy storage devices, power conversion 201 equipment or loads. An exception is that provisions relating to power conversion equipment 202 are covered only where d.c. safety issues are involved. The interconnection of small d.c. 203 conditioning units intended for connection to one or two PV modules are also included. 204 The object of this Standard is to address the design safety requirements arising from the 205 particular characteristics of photovoltaic systems. Direct current systems, and PV arrays in 206 particular, pose some hazards in addition to those derived from conventional a.c. power 207 systems, including the ability to produce and sustain electrical arcs with currents that are not 208 greater than normal operating currents. 209 In grid connected systems the safety requirements of this Standard are however critically 210 dependent on the inverters associated with PV arrays complying with the requirements of 211 IEC 62109-1 and IEC 62109-2. 212 Installation requirements are also critically dependent on compliance with IEC 60364 series 213 (see Clause 4). 214 PV arrays of less than 100 W and less than 35 V d.c. open circuit voltage at STC are not 215 covered by this Standard. PV arrays of greater than 200kW at STC are not covered by this 216 standard. 217 NOTE While this Standard applies to systems of up to 200 kW, the general requirements of this Standard may be 218 applied to larger installations. 219 220 Attention is drawn to Annex D describing arc fault detection and interruption in PV arrays. It is 221 expected that requirements for the use of this type of equipment will be included in this 222 Standard when reliable commercial equipment for detection of arcs in PV systems is 223 available. 224 NOTE 1 This Standard covers the protection requirements of PV arrays which develop as a result of the use of 225 batteries in PV systems. 226 NOTE 2 Additional requirements may be needed for more specialized installations e.g. concentrating systems, 227 tracking systems or building integrated PV.