IEC 60038:2009 pdf download.IEC standard voltages
1 Scope
This publication applies to
-a.c. transmission, distribution and utilization systems and equipment for use in such systems with standard frequencies 50 Hz and 60 Hz having a nominal voltage above 100 V;
- a.c. and d.c. traction systems;
-a.c. and d.c. equipment having nominal voltages below 120 V a.c. or below 750 V d.c.,the a.c. voltages being intended (but not exclusively) for 50 Hz and 60 Hz applications;such equipment covers batteries (from primary or secondary cells), other power supply devices (a.c. or d.c.)， electrical equipment (including industrial and communication),and appliances.
This publication does not apply to voltages representing or transmitting signals or measured values.
This publication does not apply to standard voltages of components and parts used within electrical devices or items of equipment.
This publication specifies standard voltage values which are intended to serve as preferential values for the nominal voltage of electrical supply systems, and as reference values for equipment and system design.
NOTE 1 Two main reasons have led to the values specified in this standard:
The values of nominal voltage (or highest voltage for equipment) specified in this standard are mainly based on the historical development of electrical supply systems throughout the world, since these values turned out to be the most common ones, and have achieved worldwide recognition;
The voltage ranges mentioned in this standard have been recognized to be the most appropriate ones as a basis for design and testing of electrical equipment and systems.
NOTE 2 It is nevertheless the task of system and product standards to define appropriate testing values, testing conditions and acceptance criteria.
2，Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60364-5-52: Electrical installations of buildings - Part 5-52: Selection and erection of electrical equipment一Wiring systems
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
For alternating voltages, the voltages stated below are r.m.s. values.
3.1 nominal system voltage
a suitable approximate value of voltage used to designate or identify a system [IEV 601-01-21, modified]
3.2 highest voltage of a system (excluding transient or abnormal conditions)
the highest value of operating voltage which occurs under normal operating conditions at any time and at any point on the system
NOTE It excludes transient overvoltages, such as those due to switching operations, and temporary variations of voltage.[IEV 601-01-23, modified]
3.3 lowest voltage of a system (excluding transient or abnormal conditions)
the lowest value of operating voltage which occurs under normal operating conditions at any time and at any point on the system
NOTE It excludes transient voltages, such as those due to switching operations, and temporary variations of voltage.[IEV 601-01-24, modified].IEC 60038 pdf download.