IEC 60364-5-55:2011 pdf – Electrical installations of buildings – Part 5-55: Selection and erection of electrical equipment – Other equipment.
— photovoltaic cells (IEC 60364-7-712 also applies);
— electrochemical accumulators;
— other suitable sources.
551.1.2 Generating sets with the following electrical characteristics are cons3ee1.
— mains-excited and separately excited synchronous generators;
— mains-excited and self-excited asynchronous generators;
mains-commutated and soft-commutated static converters with or without by-pass facilities:
generating sets with other suitable electrical characteristics.
551.1.3 The use of generating sets for the following purposes is considered:
— supply to permanent installations;
— supply to temporary Installations:
— supply to portable equipment which is not connected to a permanent installation:
— supply to mobile units (IEC 60364-7-717 also applies).
551.2 General requirements
551.2.1 The means of excitation and commutation shall be appropriate for the intended use of the generating set and the safety and proper functioning of other sources of supply shall not be impaired by the generating set.
NOTE See 551.? for particular requirements where the generating set may operate en parallel with S System for the desinbution of electricity to the public.
551.2.2 The prospective shot-circuit current and prospective earth fault current shall be assessed for each source of supply or combination of sources which can operate independently of other sources or combinations. The short-circuit breaking capacity of protective devices within the installation and. where appropriate, connected to a system for distribution of electricity to the public, shall not be exceeded for any of the Intended methods of operation of the sources.
NOTE Atlenhon should be given to th, power factor specified for protective devices in the installation
551.2.3 The capacity and operating characteristics of the generating set shall be such that danger or damage to equipment does not arise after the connection or disconnection of any intended load as a result of the deviation of the voltage or frequency from the intended operating range. Means shall be provided to automatically disconnect such parts of the installation as may be necessary if the capacity of the generating set is exceeded.
NOTE I Atlenleon should be given to the size of individual loads as a proportion of ih, capacity of he generating
set and to motor starting currents
NOTE 2 Attention should be given to the power factor specified for protective devices in the instailation
NOTE 3 The Installation of a generating set within an existing building or installation may change the conditions of external influence for the installation (see IEC 80364-I), for example by the introduction of moving parts, parts at high temperature or by the presence of inflammable fluids and noxious gases. etc.
551.2.4 Provision for isolation shall meet the requirements of Clause 537 for each source or combination of sources of supply.
551.3 Protective measure: extra-low-voltage provided by SELV and PELV
551.3.1 AddItional requirements for SELV and PELV where the Installation Is supplied from more than one source
Where a SELV or PELV system may be supplied by more than one source, the requirements of 414.3 of IEC 60364-4-41:2005 shall apply to each source. Where one or more of the sources is earthed. the requirements for PELV systems in 414.4 of IEC 60364-4-41:2005 shall apply.
If one or more of the sources does not meet the requirements of 414.3, the system shall be treated as a FELV system and the requirements of 411.7 of IEC 60364-4-41:2005 shall apply.
551.3.2 AddItional r.qulr.m.nts where It Is necessary to maintain th. supply to an .xtra-low voltage system
Where it is necessary to maintain the supply to an extra-low voltage system following the loss of one or more sources of supply, each source of supply or combination of sources of supply which can operate independently of other sources or combinations shall be capable of supplying the intended load of the extra-low voltage system. Provisions shall be made so that the loss of low-voltage supply to an extra-low voltage source does not lead to danger or damage to other extra-low voltage equipment.
NOTE Such precautions may be necessary In supplIes for safely services (see Clause 35 of IEC 60364-12005).
551.4 Fault protection (protection against Indirect contact)
551.4.1 Fault protection shall be provided for the installation in respect of each source of supply or combination of sources of supply that can operate independently of other sources or combinations of sources,
The fault protective provisions shall be selected or precautions shall be taken to ensure that where fault protective provisions are achieved in different ways within the same installation or part of an installation according to the active sources of supply, no influence shall occur or conditions arise that could impair the effectiveness of the fault protective provisions.