Instruction Manual

A. Technical appendix
A−7
Festo P.BE−CPX−SYS−EN en 0902e
A.2 Cable length and cross−sectional area
Note
In the following section it is assumed that the reader is
familiar with the information in the chapter Installation" in
this manual. This section is directed exclusively at person
nel trained in electrotechnology.
A load−dependent drop in voltage occurs on the cables of the
operating voltage supply to a CPX terminal. This can
cause
the voltage at pin1 or pin2 of the operating voltage connec
tion to be outside the permitted tolerance.
Recommendation:
· Avoid long distances between the power supply unit and
the CPX terminal.
· Ascertain the most suitable cross−sectional area and the
maximum cable length for the operating voltage cable in
accordance with the following formula.
Note
The following formula assumes that the cross−sectional
areas of the operating voltage supply are the same.