ABB 6401 U-102-500 Manual Del Usuario página 57

Installation
d. ... in Conjunction with Extensions
Insert 6401U-102-500 can be operated via extensions. In
this case, the following must be taken into account:
• The maximum line length depends on the maximum
permissible ripple voltage at the extension inputs. How-
ever, the ripple voltage must not exceed 100 V (in
practice, this is equivalent to a minimum line length of
100 m).
The following can be used as extensions:
- NO pushbutton (e.g., 2020 US or 2021/6 UK)
CAUTION
It is not permissible to illuminate the pushbutton
extension parallel to the switching contact. Use
pushbutton with separate "N" terminal.
NOTE
In order to ensure optimum operation, switched lines
must be laid separately to the extension lines.
GB