S.L. 545.24 · Electrical Installations Regulations (S.L. 545.24)
S.L. 545.24 Art. 18Use of standby generators with fixed installations.
Generators intended to be used as standby to supply a fixed electrical installation which is also connected to the electricity distribution system:
(a) shall be provided with a two pole (for single phase installations) or a four pole (for three phase installations) change over switch;
(b) shall not, under no circumstances, come in direct or indirect connection with the electricity distribution system.