IEC TS 62257-7-1:2006 Recommendations for small renewable energy and hybrid systems for rural electrification - Part 7-1: Generators - Photovoltaic arrays
This part of IEC 62257 specifies the general requirements for erection and operation of PV
arrays in decentralized rural electrification systems.
This technical specification contains requirements for ELV and LV PV arrays.
Particular attention must be paid to voltage level, as this is important for safety reasons and
has an influence on protective measures and on the skill and ability level of people operating
the systems.
For the sake of completeness, this technical specification gives requirements for d.c. voltages
below and above 120 V. However for rural electrification projects it is strongly recommended
to choose a voltage in the range of extra low voltage, taking into account the assumed skills
of the operators, installers and users. Nevertheless, designers must be aware that decreasing
the voltage means increasing the current and thus transferring voltage hazards to current
risks (risk of fire, etc.).
The following PV array configurations are considered (see Figure 5 to Figure 7):
a) single string of modules;
b) multi-string PV array;
c) PV array divided into several sub-arrays.
Direct current systems, and photovoltaic systems in particular, pose various hazards in
addition to those derived from conventional a.c. power systems, for example the ability to
produce and sustain electrical arcs with currents that are not much greater than normal
operating currents. This technical specification addresses those safety requirements arising
from the particular characteristics of photovoltaic systems.
The aim is to provide safety and fire protection requirements for:
? uninformed persons, including owner(s)/occupier(s) and users of the premises where
photovoltaic arrays are installed;
? informed workers (e.g. electricians) working on these systems; and
? emergency workers (for example fire fighters).
For installation of PV arrays see IEC 60364-7-712.
IEC TS 62257-7-1:2006 history
2010IEC TS 62257-7-1:2010 Recommendations for small renewable energy and hybrid systems for rural electrification – Part 7-1: Generators – Photovoltaic generators
2006IEC TS 62257-7-1:2006 Recommendations for small renewable energy and hybrid systems for rural electrification - Part 7-1: Generators - Photovoltaic arrays