Installation in air inside a room

According to IEC 60287-2-1 Ed.2.0 for a single group.

Coefficient f is used for channel acc. Heinhold. The values for one single cable, three cables spaced horizontally and three cables trefoil are given in the book 'Kabel und Leitungen für Starkstrom' by L. Heinhold, 5th edition 1999. There are no values for 2 cables nor touching cables and no difference between horizontal and vertical laying. In comparison with the value for trefoil being 2/3, the value for 3 objects touching is assumed to be 5/6 and for 2 objects touching is assumed to be 8/9.

Symbol
$inst_{t}$
Choices
IdInstallationfactor Zfactor Efactor gfactor fInfo
11 single object0.213.940.601.000Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.3D
22 objects touching, horizontal0.292.350.500.888Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.5D
32 objects spaced, horizontal (clearance > 0.75D)0.213.940.601.000Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.3D, horizontal clearance ≥ 0.75D
42 objects touching, vertical1.420.860.250.888Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.5D
52 objects spaced, vertical (clearance > D)0.752.800.301.000Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.5D, vertical clearance ≥ D
63 objects touching, horizontal0.621.950.250.833Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.5D
73 objects spaced, horizontal (clearance > 0.75D)0.213.940.601.000Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.3D, horizontal clearance ≥ 0.75D
83 objects touching, vertical1.610.420.200.833Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ D
93 objects spaced, vertical (clearance > D)1.312.000.201.000Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.5D, vertical clearance ≥ D
103 objects touching trefoil0.961.250.200.667Installation on non-continuous brackets, ladder supports or cleats, clearance to wall ≥ 0.5D