Festo Smart cubic CPV-SC Series, Manual, Page: 41 / 80

3. Installation
3-15
Festo P.BE-CPVSC-EN en 0112NH
Vacuum/low pressure operation
The CPV-SC valve terminal can be operated with vacuum or
low pressure (
<
3 bar), if regulated auxiliary pilot air is ap-
plied separately. An overview of the end plates required can
be found in Appendix A.
3.3.4 Connecting the electric cables
Warning
Use only power units which guarantee reliable isolation of
the operating voltages as per IEC 742/EN 60742/VDE 0551
with at least 4 kV isolation resistance (Protected Extra Low
Voltage PELV). Switch power packs are permitted, provid-
ing they guarantee reliable isolation in accordance with
EN 60950/VDE 0805.
Please note:
By the use of PELV power units, protection against electric
shock (protection against direct and indirect contact) is guar-
anteed with the Festo valve terminals in accordance with
EN 60204-1/IEC 204. Safety transformers with the adjacent
symbol must be used for supplying PELV networks. The valve
terminals must be earthed to ensure that they function cor-
rectly (e.g. EMC).
Please note
Check within the framework of your EMERGENCY STOP
circuit, to ascertain the measures necessary for putting
your machine/system into a safe state in the event of an
EMERGENCY STOP (e.g. switching off the operating voltage
for the valves and output modules, switching off the com-
pressed air).