Festo SBO Q Series, Manual

Page: 49 / 156

3. Installation
3−5
Festo P.BE−SBO−Q−EN en 0702a
3.1.1 Selecting the power supply unit
Warning
·
For the electric power supply, use only PELV circuits in
accordance with IEC/DIN EN 60204−1 (Protective Extra−
Low Voltage, PELV).
Also take into account the general requirements for PELV
circuits in accordance with IEC/DIN EN 60204−1.
·
Only use power sources which guarantee reliable electri
cal isolation of the operating voltage in accordance with
IEC/DIN EN 60204−1.
By using PELV circuits, protection against electric shock
(protection against direct and indirect contact) is guaranteed
in accordance with IEC/DIN EN 60204−1 (electrical machine
equipment, general requirements).
Recommendation: Use a separate regulated power supply
which does not have to supply any other devices. You will
then achieve the greatest resistance to interference.
Simple 24 V transformers with rectifier and smoothing capaci
tor achieve output voltages of 28 V and more with low output
voltages. Correct operation can only be guaranteed if the per
mitted operating voltage range is not exceeded (see Technical
Data in appendix A.4).