Festo MPA-S, Manual

Page: 84 / 174

4 Commissioning
84 Festo – P.BE-MPA-EN – 1309f – English
4.1 Prior to commissioning
• Switch off the power supply before connecting or disconnecting plug connectors (otherwise func-
tional damage).
• Only commission a valve terminal that has been mounted and wired completely.
• Make sure that there is a sufficient supply of fresh air (cooling) for the following operating condi-
tions:
– maximum number of valves
– maximum operating voltage
– endurance stress off the solenoid coil
• Please observe the subsequent instructions on pressure build-up in the overall supply.
Commissioning of the CPX terminal is described in the corresponding description for the
CPX bus node ( the system description of your CPX terminal, table “Descriptions of the
CPX terminal”).
4.1.1 Pressure build-up in the overall supply
Warning
If the pressure build-up of the pilot air supply is too slow or delayed, this may cause the
actuators to perform sudden unexpected movements under the following conditions:
– when the compressed air is connected via a soft-start valve (gradual pressure build-
up) and
– if there are electric signals (e.g. after EMERGENCY OFF).
This can cause damage to the machine or system and even injury to persons.
• Operate the valve terminal with an external pilot air supply (3 ... 8 bar). Branch the
pilot air supply off upstream of the safety start-up valve ( Fig. 4.1).
The pilot air supply must reach a pressure of 3 ... 8 bar immediately after it is switched on (dependent
on the valve, Appendix A, Fig. A.1 … Fig. A.5). Otherwise there is no guarantee that the valve will
switch directly ( Fig. 4.1). If the pressure is less than the minimum required pilot pressure, there may
be a delay before the valve reverses, despite the presence of an electric signal. The gradual pressure
build-up of the overall supply does not affect the actuator in that case. The actuator would react sud-
denly (e.g. a cylinder would extend or retract suddenly, depending on the valve function).