NEN EN 50021 : 99 C1 2000

Foreword
Section One: General
1 Scope
2 Normative references
3 Definitions
4 General requirements
Section Two: Requirements for all electrical apparatus
5 General
6 Construction
7 Connection facilities and wiring
8 Clearances, creepage distances and separations
9 Electric strength
Section Three: Supplementary requirements for non-sparking
apparatus
10 Rotating machines
11 Fuses and fuse assemblies
12 Luminaires
13 Instruments and low-power apparatus
14 Current transformers
15 Plugs and sockets
16 Cells and batteries
Section Four: Supplementary requirements for apparatus
producing arcs, sparks or hot surfaces
17 General
18 Enclosed-break devices and non-incendive components
19 Hermetically sealed device
20 Sealed device or encapsulated device
21 Energy-limited apparatus and circuits
22 Restricted-breathing enclosures
23 Simplified pressurization
Section Five: Verification and testing
24 General
25 Documents
26 Type tests
27 Routine verifications and tests
Section Six: Marking and documentation
28 Marking
29 Documentation
30 Manufacturer's responsibility
Annex A (normative) Assessment of energy-limited
apparatus and circuits by reference curves and tables

Defines requirements for construction, testing and marking of Group II electrical apparatus with type of protection "n", meant to be used solely in areas where explosive atmospheres of gas, vapour and mist are not likely to occur, or if they do, only infrequently or for a short time.