Festo CPA-SC Series, Manual

Page: 66 / 140

3. Installation
3−12
Festo P.BE−CPASC−EN en 0808c
Note
·
Internal pilot air is branched centrally from supply
channel 1 for all valve solenoid coils. This also applies
when the CPA−SC valve terminal is operated with several
pressure zones (see Fig.3/3).
External pilot air supply If the operating pressure lies below 3 bar or above 8 bar,
pilot control of the valve solenoid coils must be carried out
with external pilot air. In this case, the pilot air is supplied
externally via connection (12/14).
Note
·
Use closed−loop regulated external pilot air (3
Ū
8 bar),
reliable faultless operation of the CPA−SC valve terminal
is then possible, e.g. even with fluctuating operating
pressure.
·
The external pilot air for all valve solenoid coils is
supplied centrally via pilot connection (12/14) on the
left−hand or right−hand side of the base block. This also
applies when the CPA−SC valve terminal is operated with
different pressure zones (see Fig.3/3).
·
Set the external pilot air supply in accordance with the
operating pressure (see diagrams appendix A, Fig.A/1
and Fig.A/2).