Festo CPA-SC Series, Manual

Page: 89 / 140

4. Commissioning
4−5
Festo P.BE−CPASC−EN en 0808c
4.1.2 Pressure increase in the complete supply
Warning
If the build−up in pilot air pressure is too slow or is
delayed, the holding current reduction may prevent the
pilot solenoids from actuating the valves.
·
Make sure that the pilot air is applied in accordance with
the External pilot air diagram" (see appendix A, Fig.A/1
and Fig.A/2) when the pilot solenoids are energized in
the high current phase of 20 ms.
Warning
If the build−up in pressure of the pilot air is too slow or
delayed, this may cause the actuators to perform sudden
unexpected movements under the following conditions:
when the compressed air is switched on with a safety
start−up valve (slow build up of pressure) and
if there are electric signals (e.g. after EMERGENCY
STOP).
This can cause damage to the machine or system and even
injury to human beings.
·
Operate the valve terminal with external pilot air as a
factor of the operating pressure (see appendix A,
Fig.A/1 and Fig.A/2). Branch the pilot air in front of the
safety start−up valve (see Fig.4/1).