NBN EN 60519-21 : 2009

1 Scope
2 Normative references
3 Definitions
4 Classification of electroheat equipment according to
    voltage bands
5 Classification of electroheat equipment according to
    frequency bands
6 General requirements
7 Prohibition of the use of earth as part of an active
    circuit
8 Marking, labelling and circuit diagrams
9 Protection against overcurrent
10 Isolation and switching
11 Connection to the supply network and internal connections
12 Protection against electric shock
13 Protection against thermal influences
14 Risk of fire and danger of explosion
15 Inspection, commissioning, utilization and maintenance of
    electroheat installations
Annex ZA Normative references to international publications with
their corresponding European publications

Applicable to the protecting of persons from contact with current from electrically heated equipment for melting glass. Describes also the safety aspects of electrical parts where electrical heating is combined with other methods of heating, such as liquid fuel heating.