What is the minimum clearance between phases and ground for the secondary side connections for Trihal Transformers?

Issue:
Minimum clearance between phases and ground for the secondary side connections for Trihal Transformers

Product Line:
Trihal Medium Voltage Transformer

Resolution:
For low voltage connections (< 1100 V), the standardized distances between phases are defined by standards IEC 1439 and IEC 60664-1.
For a nominal voltage of 1000 V, with an overvoltage category III (impulse voltage of 8000 V) and a pollution degree 3 (industrial environment), the minimum air gap between two conductors is 8 mm.

Distance between phases:
Minimum 8 mm

Distance between phase and ground:
Minimum 10 mm with an insulating screen
Minimum 21 mm in air

Please see attached file for reference

Released for: Schneider Electric South Africa