Siemens Sentron 3VA Manual page 171

Cable classes according to UL 486 and IEC 60228:
①
Cable with solid wire in core
②
Cable with stranded wires in core
③
Cable with stranded wires in core
④
Cable with a large number of extra finely stranded conductors
The conductors of class 1 / solid and class 2 / B refer to rigid conductors, solid and stranded.
These are used predominantly in applications with low-curvature cable bending radii and in
fixed or inflexible installations.
Flexible conductors of class 5 / C and class 6 permit higher-curvature cable bending radii.
Solid cables of class 1 / solid are normally used only up to a cross section of 16 mm² (IEC) /
AWG 10 (UL).
Please note: Solid-conductor cables in classes 1 / solid and 2 / B are smaller in diameter
than cables in classes 5 / C and 6 even when their cross sectional area is the same. As a
result, cables with the same diameter from different classes may have different connection
cross sections.
3VA molded case circuit breakers with UL and IEC certification
Manual, 01/2019, L1V30435333-01
Accessories
4.3 Connection system
UL 486 IEC 60228
Solid Class 1
Class B Class 2
Class C Class 5
Class 6
169